Serpentine tensioner pulley bearing
Discussion
I've checked some of the old threads and yes, I know a lot of people eliminate the spring tensioner but I'd decided to retain mine. Makes belt changing or replacement a roadside job.
The pulley had a slight rattle. Not terrible, only apparent with the bonnet up, but needed sorting. I got the tensioner and pulley wheel off, only to find that the bearing NTN 6203LB seems to be very hard to get. Only available online from USA stockist it seems. I admit I haven't tried a bearing specialist in the UK by phone, they're all closed at them moment. Holidays pah!!
I haven't been able to get the old bearing out either. I've tried the old G clamp with sockets / washers trick but it won't budge. Old threads suggest it is peened over in there but it doesn't look like that to me. The wheel is only plastic so I doubt a huge press is required?
This and the fact that I damaged the collar on the mounting before I realised it was left hand thread
has led me to getting the whole lot for a princely £27.15. (Available for £40 + VAT + delivery from guess who) A Land Rover Bearmach item (ERR6439). Even cheaper if a Land Rover specialist was near enough for me to go and collect it!
But it would be nice to know how to replace and where to obtain the bearing if it goes again. Some owners have had them fail regularly due to the heat under there. One (COG) - 15k miles!
The pulley had a slight rattle. Not terrible, only apparent with the bonnet up, but needed sorting. I got the tensioner and pulley wheel off, only to find that the bearing NTN 6203LB seems to be very hard to get. Only available online from USA stockist it seems. I admit I haven't tried a bearing specialist in the UK by phone, they're all closed at them moment. Holidays pah!!
I haven't been able to get the old bearing out either. I've tried the old G clamp with sockets / washers trick but it won't budge. Old threads suggest it is peened over in there but it doesn't look like that to me. The wheel is only plastic so I doubt a huge press is required?
This and the fact that I damaged the collar on the mounting before I realised it was left hand thread
has led me to getting the whole lot for a princely £27.15. (Available for £40 + VAT + delivery from guess who) A Land Rover Bearmach item (ERR6439). Even cheaper if a Land Rover specialist was near enough for me to go and collect it!But it would be nice to know how to replace and where to obtain the bearing if it goes again. Some owners have had them fail regularly due to the heat under there. One (COG) - 15k miles!
Just move on to the JE alternator bracket, the original tensioner jockey wheel and bearing is a poor quality thing and the cheap pattern part replacements are worse still.
Not sure why you think you wouldn't be able to easily fit a new belt with the JE bracket? The type of belt used lasts almost indefinitely and if it did fail replacing it if you have a JE bracket fitted is easy.
It sounds like you're giving yourself a lot of pointless stress over a small detail where there's already a neat solution available to the poor quality original sprung jockey wheel with its short lived bearing.
Not sure why you think you wouldn't be able to easily fit a new belt with the JE bracket? The type of belt used lasts almost indefinitely and if it did fail replacing it if you have a JE bracket fitted is easy.
It sounds like you're giving yourself a lot of pointless stress over a small detail where there's already a neat solution available to the poor quality original sprung jockey wheel with its short lived bearing.
You must be very bored.
Mine was same after about 50,000 miles, someone might have changed it in the past but I think it was the original one.
Just a slight swish rather than a whine and I lived with it for about a year. You might be pleasantly surprised how quite it is after replacement.
I quite like the new one as it’s shiny
I did notice the new one seems to hold the belt tighter when you blip the throttle as the belt didn’t sort of vibrate like it used to.
Mine was same after about 50,000 miles, someone might have changed it in the past but I think it was the original one.
Just a slight swish rather than a whine and I lived with it for about a year. You might be pleasantly surprised how quite it is after replacement.
I quite like the new one as it’s shiny
I did notice the new one seems to hold the belt tighter when you blip the throttle as the belt didn’t sort of vibrate like it used to.
ChimpOnGas said:
Just move on to the JE alternator bracket, the original tensioner jockey wheel and bearing is a poor quality thing and the cheap pattern part replacements are worse still.
Not sure why you think you wouldn't be able to easily fit a new belt with the JE bracket? The type of belt used lasts almost indefinitely and if it did fail replacing it if you have a JE bracket fitted is easy.
It sounds like you're giving yourself a lot of pointless stress over a small detail where there's already a neat solution available to the poor quality original sprung jockey wheel with its short lived bearing.
I'm no stressing over it. Not even driving the car at the moment. I just wondered (on a thumb-twiddling cold day I grant you, with the ashes cricket highlights on, good for once!) if anyone had followed up on the other threads I read about swapping out the bearing. The original had lasted 21 years.Not sure why you think you wouldn't be able to easily fit a new belt with the JE bracket? The type of belt used lasts almost indefinitely and if it did fail replacing it if you have a JE bracket fitted is easy.
It sounds like you're giving yourself a lot of pointless stress over a small detail where there's already a neat solution available to the poor quality original sprung jockey wheel with its short lived bearing.
You only need a 15" socket wrench to bear on the tensioner and swap the belt. Seconds. The JE bracket way looks a bit old-fashioned to me; especially when if you watch the engine idling, the spring tensioner moves slightly all the time. At least mine does! It's a fixed belt pathway any other way that would move between over and under tight. Spring tensioners were also fitted to Range Rovers. I didn't buy a pattern part, I ordered Bearmach. You can buy second-hand for about £10 on ebay but that is penny pinching, even for me.
The jokey references to the 'banana' bracket and missing bolts in the other threads lent me to getting whole new one, delivered.
Other users of Pistonheads may like to swap out just the bearing if it's possible, bu aside from Amazon / eBay (USA), I haven't found any listed.
I agree with the above. If that tensioner takes out some torque that’s otherwise delivered to more important bearings like the water pump or alternator I’ll leave well alone.
And yes if I had a warm garage I’d probably be considering this on a cold winters day for kicks.
Would the pulley wheel have been warmed up before the bearing pushed in I wonder?
And yes if I had a warm garage I’d probably be considering this on a cold winters day for kicks.
Would the pulley wheel have been warmed up before the bearing pushed in I wonder?
ianwayne said:
the bearing NTN 6203LB seems to be very hard to get.
NTN is I guess the Brand, possibly not available in UK?6203 is the size and the LB bit refers to the seal, but not a terminology used in UK. Don't see why this little chap shouldn't do the job?
Changed mine some time back when I had a Chimaera. Seem to recall some plastic has to be cut away, as if the bearing is moulded into the pulley.
Contributor Steve_D of Southways said on this thread I've found from 2016 that he keeps them in stock:
https://www.pistonheads.com/gassing/topic.asp?h=0&...
https://www.pistonheads.com/gassing/topic.asp?h=0&...
I had no problem finding the bearing....but.
I have tried to replace bearings recently and find later (possibly aftermarket) tension pulleys are moulded around the bearing and I have not been able to do the job sensibly meaning we are a business so spending time trying to dremel the plastic away from one side of the bearing so it can be pressed out is not cost effective for a customers car. A whole new tensioner with pulley is about £23 so you can't put much time into replacing a bearing.
Steve
Southways
I have tried to replace bearings recently and find later (possibly aftermarket) tension pulleys are moulded around the bearing and I have not been able to do the job sensibly meaning we are a business so spending time trying to dremel the plastic away from one side of the bearing so it can be pressed out is not cost effective for a customers car. A whole new tensioner with pulley is about £23 so you can't put much time into replacing a bearing.
Steve
Southways
Classic Chim said:
I agree with the above. If that tensioner takes out some torque that’s otherwise delivered to more important bearings like the water pump or alternator I’ll leave well alone.
I just don't buy this, simply use the age old method of tensioning by setting the belt it so you can just turn it 90 degrees with your thumb and forefinger on the longest run, if you follow this tried and tested procedure you will not be overstessing your PS pump, alternator, or water pump bearings... 
People need to understand that all the kicking and jumping you see from that nasty cheap plastic sprung jockey wheel is in fact belt whip, and the thing is it's actually the a sprung jockey wheel that allows this whip. As the belt whips, the sprung jockey wheel kicks, this kick in turn loads and unloads the bearings in the PS pump, alternator & water pump.
The undesirable belt whip causes a violent on/off torque reaction which is most definitely not good for those bearings or smooth alternator output, the truth is if you ditch the nasty cheap plastic sprung jockey wheel and go with a correctly adjusted rigid tensioning system such as the JE alternator bracket you eliminate this undesirable belt whip in a stroke.
Belt whip is also a well know way to shorten the life expectancy of a drive belt, the on/off torque reaction increases and decreases the friction the belt has on the pulleys, what you're introducing is tiny moments of slip, all be it measured in milliseconds.... but make no mistake all the tiny periods of slip quickly add up.
Fit the JE alternator bracket and correctly tension the belt and you completely eliminate all this whip, kick & slip..... and the undesirable effects of the on/off torque reaction it places on both the belt and the bearings in the accessories it's driving. In summary the reality is assuming you've correctly tensioned your belt, the JE alternator bracket is actually better for bearing and belt life not worse!
I'm not saying the nasty cheap plastic sprung jockey wheel is a belt or ancillary killer as such, obviously it's not, but my point is those suggesting the JE bracket is worse for bearing life actually have it back to front, if you want the better system it'll be the JE bracket every time.
Seriously folks.... get shot of that nasty cheap plastic sprung jockey wheel and go with a correctly adjusted rigid tensioning system such as the JE alternator bracket, it's a far better and way more reliable setup...
Just make sure you tension the belt correctly.....
https://www.youtube.com/watch?v=FMiB3CnZpRc
Instead of wasting your life reading all that waffle above, you can take a quick peek at Gates website. For those who do not know - seems to be at least one on here - Gates are the most respected and world leaders in automotive belts. This is what they have to say:
"Belt tensioners are extremely important in the proper operation of the accessory belt drive system. A tensioner maintains the correct amount of tension on the belt at all times throughout its duty cycle. It also helps protect other components such as the alternator and water pump from undue stress and premature failure. In addition, a tensioner is a relatively inexpensive part to replace. So, every time you replace a multi-ribbed belt, be sure to replace the tensioner at the same time."
And some useful information on identifying tensioner problems in the link.
https://www.gatestechzone.com/en/problem-diagnosis...
And another website seems to agree strangely enough:
"Belt tensioners were first used back in the late 1970s. These early units were fixed tensioners that required manual adjustment. Then automatic belt tensioners arrived in the mid-1980s. The spring-loaded design eliminated the need for manual adjustments and assured proper belt tension for the life of the belt. Because of this, the tensioner is often overlooked when a belt is replaced. Even so, the tensioner should always be inspected when changing a belt"
http://www.aa1car.com/library/belt_tensioners.htm
Firestone agree with this too:
"Many of today’s vehicles are equipped with a self-tensioning device called an automatic belt tensioner. These tensioners are designed to hold a predetermined amount of tension on the serpentine belt so it functions properly and keeps your car cruising.
Your serpentine belt is like one giant, fast-spinning rubber band. And, like a rubber band, it must maintain a balance of flexibility and tension. Most tensioners feature an internal spring and pulley, which applies needed force against the serpentine belt to keep it tight. If there is not enough tension, a belt can slip, squeal or run hot. Worst-case scenario: a loose belt may come off of its pulleys. When this happens, all the accessories powered by the engine go kaput and the vehicle will stop running."
http://blog.firestonecompleteautocare.com/maintena...
Edited by N7GTX on Friday 29th December 16:13
ChimpOnGas said:
I just don't buy this, simply use the age old method of tensioning by setting the belt it so you can just turn it 90 degrees with your thumb and forefinger on the longest run, if you follow this tried and tested procedure you will not be overstessing your PS pump, alternator, or water pump bearings...
People need to understand that all the kicking and jumping you see from that nasty cheap plastic sprung jockey wheel is in fact belt whip, and the thing is it's actually the a sprung jockey wheel that allows this whip. As the belt whips, the sprung jockey wheel kicks, this kick in turn loads and unloads the bearings in the PS pump, alternator & water pump.
The undesirable belt whip causes a violent on/off torque reaction which is most definitely not good for those bearings or smooth alternator output, the truth is if you ditch the nasty cheap plastic sprung jockey wheel and go with a correctly adjusted rigid tensioning system such as the JE alternator bracket you eliminate this undesirable belt whip in a stroke.
Belt whip is also a well know way to shorten the life expectancy of a drive belt, the on/off torque reaction increases and decreases the friction the belt has on the pulleys, what you're introducing is tiny moments of slip, all be it measured in milliseconds.... but make no mistake all the tiny periods of slip quickly add up.
Fit the JE alternator bracket and correctly tension the belt and you completely eliminate all this whip, kick & slip..... and the undesirable effects of the on/off torque reaction it places on both the belt and the bearings in the accessories it's driving. In summary the reality is assuming you've correctly tensioned your belt, the JE alternator bracket is actually better for bearing and belt life not worse!
I'm not saying the nasty cheap plastic sprung jockey wheel is a belt or ancillary killer as such, obviously it's not, but my point is those suggesting the JE bracket is worse for bearing life actually have it back to front, if you want the better system it'll be the JE bracket every time.
Seriously folks.... get shot of that nasty cheap plastic sprung jockey wheel and go with a correctly adjusted rigid tensioning system such as the JE alternator bracket, it's a far better and way more reliable setup...
Just make sure you tension the belt correctly.....
https://www.youtube.com/watch?v=FMiB3CnZpRc
In this case on a Tvr that may well be. People need to understand that all the kicking and jumping you see from that nasty cheap plastic sprung jockey wheel is in fact belt whip, and the thing is it's actually the a sprung jockey wheel that allows this whip. As the belt whips, the sprung jockey wheel kicks, this kick in turn loads and unloads the bearings in the PS pump, alternator & water pump.
The undesirable belt whip causes a violent on/off torque reaction which is most definitely not good for those bearings or smooth alternator output, the truth is if you ditch the nasty cheap plastic sprung jockey wheel and go with a correctly adjusted rigid tensioning system such as the JE alternator bracket you eliminate this undesirable belt whip in a stroke.
Belt whip is also a well know way to shorten the life expectancy of a drive belt, the on/off torque reaction increases and decreases the friction the belt has on the pulleys, what you're introducing is tiny moments of slip, all be it measured in milliseconds.... but make no mistake all the tiny periods of slip quickly add up.
Fit the JE alternator bracket and correctly tension the belt and you completely eliminate all this whip, kick & slip..... and the undesirable effects of the on/off torque reaction it places on both the belt and the bearings in the accessories it's driving. In summary the reality is assuming you've correctly tensioned your belt, the JE alternator bracket is actually better for bearing and belt life not worse!
I'm not saying the nasty cheap plastic sprung jockey wheel is a belt or ancillary killer as such, obviously it's not, but my point is those suggesting the JE bracket is worse for bearing life actually have it back to front, if you want the better system it'll be the JE bracket every time.
Seriously folks.... get shot of that nasty cheap plastic sprung jockey wheel and go with a correctly adjusted rigid tensioning system such as the JE alternator bracket, it's a far better and way more reliable setup...
Just make sure you tension the belt correctly.....
https://www.youtube.com/watch?v=FMiB3CnZpRc
I sold a lot of fan belts back in the day and usually because the old ones had stretched beyond serviceable use so I’m not sure if the old way of doing it is actually that superior
The cheap nasty plastic wheel is pretty reliable and if you buy a decent one keeps the belt taught and you have no vibration or flexing of it to mention in my experience.
What it does do is keep the belt on there and you have little chance of belt loss where as you have to keep an eye on one that has no spring tension as if it gets loose your asking for disaster.
I’m over playing it for laughs
but again back in the day I sold plenty of belts that had been lost from the car, snapped. Obviously Tvr owners are likely to keep a decent service schedule and breaking belts unlikely. Being a TVR I can see the attraction of removing the great block of alloy that signifies RR.
A belt held under the correct tension by a JE bracket is no different from a belt held under the correct tension by a healthy sprung tensioner! The point is if you take the trouble to check you'll find most sprung tensioners on TVR Chimaeras are a long long way off being healthy
The idea you need a sprung tensioner to absorb some sort of mysterious shock loads from the engine under normal running conditions is of course complete nonsense, no such shock should be present under normal running, additional torque loadings on the belt only exist momentarily under cranking or very hard acceleration, and even then only for a split second. With the engine at idle you shouldn't see any significant kick from a sprung tensioner unless you have a missfire (not uncommon on Chimaeras), or more likely if your sprung tensioner's spring has gone weak.
Unfortunately most Chimaeras have a kicking tensioner because the spring has been weakened by manifold heat, this is a fault that should be corrected with either a new sprung tensioner or better still a JE alternator bracket.
All the belt manufacturers are saying is a repetition of my clear point, IE the importance of ensuring correct belt tension. You can achieve this equally easily with a healthy sprung tensioner or a JE alternator bracket and the 90 degree rule (correct maintenance). The belt manufacturers recommend regularly replacing sprung tensioners (often overlooked) because they know they lose their spring tension over time, this is even more important on a Chimaera as the manifold heat definitely cooks the spring making it go weak in very short order.
If you think about it this recommendation to regularly replace a sprung tensioner is no different to the old school requirement on a manually adjusted system to every now and then make a small tweak of the belt tension. Whatever system you use the important point is you must always maintain the correct tension on the belt. The uncomfortable truth is the effectiveness of the sprung tensioner is often over looked because people mistakenly see it as a fit and forget item which it most certainly isn't...
I would put money on most of the sprung tensioners fitted to Chimaeras out there either having a weak spring or a shot bearing.... and most of them will have both!
If working correctly (and most on TVRs aren't) sprung auxiliary belt tensioners are indeed an excellent invention, but they really only came about because manual adjustment on engines fitted with cam belts is impractical. People often failed to tension their auxiliary belt correctly too, so in the case of auxiliary belt tentioning the sprung tensioner is mostly just a solution for poor maintenance, ie failure to annually check and adjust belt tension if required. If you check and adjust the belt correctly on an annual basis (which is hardly a chore on a TVR), a fixed system is better, however if you are an OEM looking for any way possible to make your service costs look lower to prospective customers, especially on a front wheel drive transverse engine where auxiliary belt belt/alternator accessibility can also be tiresome, then the sprung tensioner is an excellent idea.
When you see that sprung tensioner kick on your TVR the belt is whipping and the tensioner needs replacing, spend your £25 or so on a new one by all means, it'll stop the problem for a while but in my experience that spring will go weak again in as little as 6,000 miles. On the other hand if you have a manually adjustable system you'll never have a spring go weak and you'll save the cost of buying a JE bracket in sprung tensioners pretty quickly.
Buy a JE alternator bracket and you'll never need to buy another nasty plastic tentioner again, simply check the belt tension annually and adjust as required following the 90 degree twist rule, a process that is easy and of course completely free. The JE bracket is definitely a more reliable and cost effective solution for people who understand the importance of proper maintenance, but you do need to following the correct tensioning procedure. The sprung tensioner on the other hand is better for those who mistakenly think so called fit and forget solutions are the answer or for people who dont mind shelling out on a new sprung tensioner (and fitting it) every few years.
Of course all the above only applies to an auxiliary belt on something like a TVR Chimaera where accessibility is easy, as previously stated sprung tensioners really came from cam belt technology where they are essential because you wouldn't want to be manually adjusting your cam belt annually as it would be a real pain. Obviously when you replace a cam belt you should also replace the tensioner (if indeed a sprung one is used) which further supports my case for the need for regular replacement of your sprung auxiliary belt tensioner if that's your bag.
I prefer to check/manually adjust my belt tension rather than relying on a sprung tensioner that costs £25 plus every time it fails, adjusting belt tension on a TVR Chimaera is such a quick and simple maintenance task the JE bracket really becomes a no-brainer, a 90 degree twist check takes seconds and an adjust takes less than 5 minutes.
The idea you need a sprung tensioner to absorb some sort of mysterious shock loads from the engine under normal running conditions is of course complete nonsense, no such shock should be present under normal running, additional torque loadings on the belt only exist momentarily under cranking or very hard acceleration, and even then only for a split second. With the engine at idle you shouldn't see any significant kick from a sprung tensioner unless you have a missfire (not uncommon on Chimaeras), or more likely if your sprung tensioner's spring has gone weak.
Unfortunately most Chimaeras have a kicking tensioner because the spring has been weakened by manifold heat, this is a fault that should be corrected with either a new sprung tensioner or better still a JE alternator bracket.
All the belt manufacturers are saying is a repetition of my clear point, IE the importance of ensuring correct belt tension. You can achieve this equally easily with a healthy sprung tensioner or a JE alternator bracket and the 90 degree rule (correct maintenance). The belt manufacturers recommend regularly replacing sprung tensioners (often overlooked) because they know they lose their spring tension over time, this is even more important on a Chimaera as the manifold heat definitely cooks the spring making it go weak in very short order.
If you think about it this recommendation to regularly replace a sprung tensioner is no different to the old school requirement on a manually adjusted system to every now and then make a small tweak of the belt tension. Whatever system you use the important point is you must always maintain the correct tension on the belt. The uncomfortable truth is the effectiveness of the sprung tensioner is often over looked because people mistakenly see it as a fit and forget item which it most certainly isn't...
I would put money on most of the sprung tensioners fitted to Chimaeras out there either having a weak spring or a shot bearing.... and most of them will have both!
If working correctly (and most on TVRs aren't) sprung auxiliary belt tensioners are indeed an excellent invention, but they really only came about because manual adjustment on engines fitted with cam belts is impractical. People often failed to tension their auxiliary belt correctly too, so in the case of auxiliary belt tentioning the sprung tensioner is mostly just a solution for poor maintenance, ie failure to annually check and adjust belt tension if required. If you check and adjust the belt correctly on an annual basis (which is hardly a chore on a TVR), a fixed system is better, however if you are an OEM looking for any way possible to make your service costs look lower to prospective customers, especially on a front wheel drive transverse engine where auxiliary belt belt/alternator accessibility can also be tiresome, then the sprung tensioner is an excellent idea.
When you see that sprung tensioner kick on your TVR the belt is whipping and the tensioner needs replacing, spend your £25 or so on a new one by all means, it'll stop the problem for a while but in my experience that spring will go weak again in as little as 6,000 miles. On the other hand if you have a manually adjustable system you'll never have a spring go weak and you'll save the cost of buying a JE bracket in sprung tensioners pretty quickly.
Buy a JE alternator bracket and you'll never need to buy another nasty plastic tentioner again, simply check the belt tension annually and adjust as required following the 90 degree twist rule, a process that is easy and of course completely free. The JE bracket is definitely a more reliable and cost effective solution for people who understand the importance of proper maintenance, but you do need to following the correct tensioning procedure. The sprung tensioner on the other hand is better for those who mistakenly think so called fit and forget solutions are the answer or for people who dont mind shelling out on a new sprung tensioner (and fitting it) every few years.
Of course all the above only applies to an auxiliary belt on something like a TVR Chimaera where accessibility is easy, as previously stated sprung tensioners really came from cam belt technology where they are essential because you wouldn't want to be manually adjusting your cam belt annually as it would be a real pain. Obviously when you replace a cam belt you should also replace the tensioner (if indeed a sprung one is used) which further supports my case for the need for regular replacement of your sprung auxiliary belt tensioner if that's your bag.
I prefer to check/manually adjust my belt tension rather than relying on a sprung tensioner that costs £25 plus every time it fails, adjusting belt tension on a TVR Chimaera is such a quick and simple maintenance task the JE bracket really becomes a no-brainer, a 90 degree twist check takes seconds and an adjust takes less than 5 minutes.
Some sweeping statements there.
I got my car at 38,000 miles and 10 years old.
I replaced the tensioner at 66,000 miles as the wheel was starting to make noise.
When I got the car the tensioner showed exactly the same darkened colour and level of oxidisation as the rest of the engine so was most likely the original one or near as damn it
That’s hardly having to change it every few years Dave!
If you prefer one or the other then fit it.
But all that is a figment of a vivid imagination and or RR f
ked up big time with that cheap nasty often useless pulley wheel.
I’ve not heard of any cases off RR throwing or breaking belts.
The tensioner must do a decent job or it would have been binned years ago!
You paint a picture of utter incompetence from RR to use said pulley wheel, just don’t add up as there’s no real evidence to support such claims.
A cheap copy, but a decent one does the job and appears to go on for years on some applications including my own Tvr.
I’ve done nearly 8000 miles since I fitted it so should I expect imminent failure very shortly!!?!
I got my car at 38,000 miles and 10 years old.
I replaced the tensioner at 66,000 miles as the wheel was starting to make noise.
When I got the car the tensioner showed exactly the same darkened colour and level of oxidisation as the rest of the engine so was most likely the original one or near as damn it
That’s hardly having to change it every few years Dave!
If you prefer one or the other then fit it.
But all that is a figment of a vivid imagination and or RR f
ked up big time with that cheap nasty often useless pulley wheel. I’ve not heard of any cases off RR throwing or breaking belts.
The tensioner must do a decent job or it would have been binned years ago!
You paint a picture of utter incompetence from RR to use said pulley wheel, just don’t add up as there’s no real evidence to support such claims.
A cheap copy, but a decent one does the job and appears to go on for years on some applications including my own Tvr.
I’ve done nearly 8000 miles since I fitted it so should I expect imminent failure very shortly!!?!
New tensioner arrived and fitted it. Much stiffer than the old one so it was most likely the original. Glad I didn't just try to change the pulley wheel bearing now.
I have no misfire (canems) and the pulley wheel still moves very slightly when the engine is idling. Albeit at 1600 rpm on a cold engine.
I have no misfire (canems) and the pulley wheel still moves very slightly when the engine is idling. Albeit at 1600 rpm on a cold engine.
N7GTX said:
Instead of wasting your life reading all that waffle above, you can take a quick peek at Gates website. For those who do not know - seems to be at least one on here - Gates are the most respected and world leaders in automotive belts. This is what they have to say:
"Belt tensioners are extremely important in the proper operation of the accessory belt drive system. A tensioner maintains the correct amount of tension on the belt at all times throughout its duty cycle. It also helps protect other components such as the alternator and water pump from undue stress and premature failure. In addition, a tensioner is a relatively inexpensive part to replace. So, every time you replace a multi-ribbed belt, be sure to replace the tensioner at the same time."
And some useful information on identifying tensioner problems in the link.
https://www.gatestechzone.com/en/problem-diagnosis...
And another website seems to agree strangely enough:
"Belt tensioners were first used back in the late 1970s. These early units were fixed tensioners that required manual adjustment. Then automatic belt tensioners arrived in the mid-1980s. The spring-loaded design eliminated the need for manual adjustments and assured proper belt tension for the life of the belt. Because of this, the tensioner is often overlooked when a belt is replaced. Even so, the tensioner should always be inspected when changing a belt"
http://www.aa1car.com/library/belt_tensioners.htm
Firestone agree with this too:
"Many of today’s vehicles are equipped with a self-tensioning device called an automatic belt tensioner. These tensioners are designed to hold a predetermined amount of tension on the serpentine belt so it functions properly and keeps your car cruising.
Your serpentine belt is like one giant, fast-spinning rubber band. And, like a rubber band, it must maintain a balance of flexibility and tension. Most tensioners feature an internal spring and pulley, which applies needed force against the serpentine belt to keep it tight. If there is not enough tension, a belt can slip, squeal or run hot. Worst-case scenario: a loose belt may come off of its pulleys. When this happens, all the accessories powered by the engine go kaput and the vehicle will stop running."
http://blog.firestonecompleteautocare.com/maintena...
Edited by N7GTX on Friday 29th December 16:13
For once my gut reaction about this seems to have paid off.
Do I remember early Pinto engines from the mid 70’s eating belts, both slipping and breaking or was that a wives tale,, I’m sure that’s why I like a tensioner though,,,
ianwayne said:
New tensioner arrived and fitted it. Much stiffer than the old one
Like I said the tensioner loses it's spring tension, this happens faster than you think in a TVR Chimaera due to manifold heat, so do keep an eye on it.... along with the bearing life.The thing was designed for a Range Rover, so was never intended to tolerate the kind of heat it must endure on a Chimera with it's forward facing manifolds.
Personally and after two failures I'm glad to see the back of mine, horses for courses but the JE alternator has proved to be an excellent and permanent solution for me.
Classic Chim said:
N7GTX said:
Instead of wasting your life reading all that waffle above, you can take a quick peek at Gates website. For those who do not know - seems to be at least one on here - Gates are the most respected and world leaders in automotive belts. This is what they have to say:
"Belt tensioners are extremely important in the proper operation of the accessory belt drive system. A tensioner maintains the correct amount of tension on the belt at all times throughout its duty cycle. It also helps protect other components such as the alternator and water pump from undue stress and premature failure. In addition, a tensioner is a relatively inexpensive part to replace. So, every time you replace a multi-ribbed belt, be sure to replace the tensioner at the same time."
And some useful information on identifying tensioner problems in the link.
https://www.gatestechzone.com/en/problem-diagnosis...
And another website seems to agree strangely enough:
"Belt tensioners were first used back in the late 1970s. These early units were fixed tensioners that required manual adjustment. Then automatic belt tensioners arrived in the mid-1980s. The spring-loaded design eliminated the need for manual adjustments and assured proper belt tension for the life of the belt. Because of this, the tensioner is often overlooked when a belt is replaced. Even so, the tensioner should always be inspected when changing a belt"
http://www.aa1car.com/library/belt_tensioners.htm
Firestone agree with this too:
"Many of today’s vehicles are equipped with a self-tensioning device called an automatic belt tensioner. These tensioners are designed to hold a predetermined amount of tension on the serpentine belt so it functions properly and keeps your car cruising.
Your serpentine belt is like one giant, fast-spinning rubber band. And, like a rubber band, it must maintain a balance of flexibility and tension. Most tensioners feature an internal spring and pulley, which applies needed force against the serpentine belt to keep it tight. If there is not enough tension, a belt can slip, squeal or run hot. Worst-case scenario: a loose belt may come off of its pulleys. When this happens, all the accessories powered by the engine go kaput and the vehicle will stop running."
http://blog.firestonecompleteautocare.com/maintena...
Edited by N7GTX on Friday 29th December 16:13
For once my gut reaction about this seems to have paid off.
Do I remember early Pinto engines from the mid 70’s eating belts, both slipping and breaking or was that a wives tale,, I’m sure that’s why I like a tensioner though,,,
they did however change to a dual belt system when bigger alternators and PAS pumps become standard on Sierra's,Granada's etc, just think of all those cars years ago that run serp belts with no auto tensioner's e.g Honda Nissan Mitsubishi VAG etc with no reliability woes in fact a serp belt tensioned correctly needs no more adjustment in its service life in my experience Sardonicus said:
ope not so they did however change to a dual belt system when bigger alternators and PAS pumps become standard on Sierra's,Granada's etc, just think of all those cars years ago that run serp belts with no auto tensioner's e.g Honda Nissan Mitsubishi VAG etc with no reliability woes in fact a serp belt tensioned correctly needs no more adjustment in its service life in my experience
I see what you have done there Simon. You just happened to pick the most reliable brands available they did however change to a dual belt system when bigger alternators and PAS pumps become standard on Sierra's,Granada's etc, just think of all those cars years ago that run serp belts with no auto tensioner's e.g Honda Nissan Mitsubishi VAG etc with no reliability woes in fact a serp belt tensioned correctly needs no more adjustment in its service life in my experience So, my guess is you have the manual tensioner on your car then?
Of course when I was tensioning the belts you mentioned, there was a tension given by the manufacturer to ensure longevity of the associated components. I don't seem to have one for Rover V8s (except V belts that is).
The only advantage I am seeing is a minute weight saving and some bling
Unless you are an experienced mechanic, and the majority of owners are not, then sticking with Gates and Firestone has to be the best way. N7GTX said:
Sardonicus said:
ope not so they did however change to a dual belt system when bigger alternators and PAS pumps become standard on Sierra's,Granada's etc, just think of all those cars years ago that run serp belts with no auto tensioner's e.g Honda Nissan Mitsubishi VAG etc with no reliability woes in fact a serp belt tensioned correctly needs no more adjustment in its service life in my experience
I see what you have done there Simon. You just happened to pick the most reliable brands available they did however change to a dual belt system when bigger alternators and PAS pumps become standard on Sierra's,Granada's etc, just think of all those cars years ago that run serp belts with no auto tensioner's e.g Honda Nissan Mitsubishi VAG etc with no reliability woes in fact a serp belt tensioned correctly needs no more adjustment in its service life in my experience So, my guess is you have the manual tensioner on your car then?
Of course when I was tensioning the belts you mentioned, there was a tension given by the manufacturer to ensure longevity of the associated components. I don't seem to have one for Rover V8s (except V belts that is).
The only advantage I am seeing is a minute weight saving and some bling
Unless you are an experienced mechanic, and the majority of owners are not, then sticking with Gates and Firestone has to be the best way. 
but yes the JE just removes clutter no other advantage really, the serp tensioner works fine providing the tensioner is brander e.g Gates INA etc its all personal choice Gassing Station | Chimaera | Top of Page | What's New | My Stuff