Horrendous transmission noises in a selection of Caterham's
Discussion
REALIST123 said:
So it’s worth examining. I’m still wondering if enough movement is to be found in the bolts but if I can get some movement in the lower bracket to chassis bolts the front of the diff will go up and the rear come down, which might make a noticeable change to the angle. Not the same with the diff to bracket bolts, where one point is at the extreme top rear so any play will only allow a small movement up at the front.
What about moving the engine inclination? Does it mean lifting the rear of the motor? That feels possible. If it;s the other way, could be harder.Bert
Engine would need lifting at the front Bert.
Latest theory is that I shouldn’t have dropped the diff from the bracket but should have removed the whole assembly.
Apparently, the bracket is quite stressed, witnessed by the advice from CC to grind a chamfer on the long bolt, line it up and hammer it home.
If you take the diff from the bracket, that stress is released, the bracket moves and it doesn’t go back where it was when you bolt the diff back in. The diff needs to be bolted in to the bracket off the car.
Any comments welcome.
Latest theory is that I shouldn’t have dropped the diff from the bracket but should have removed the whole assembly.
Apparently, the bracket is quite stressed, witnessed by the advice from CC to grind a chamfer on the long bolt, line it up and hammer it home.
If you take the diff from the bracket, that stress is released, the bracket moves and it doesn’t go back where it was when you bolt the diff back in. The diff needs to be bolted in to the bracket off the car.
Any comments welcome.
Your asking my to help, so here I am helping.
It's said that previously the diff was quite quiet. We can eliminate the angle of the engine and/or diff, because as far as we have been told , this has never changed.
The main event that caused all the noise appears to be the rebuild of the diff. Therefore as I said before, I would start with replacing the oil with the recommended highest quality. If no change, return the diff to the rebuilder.
I would expect any prop misalignment, play or poor balance to cause terrible vibration and probably damage the gearbox rear oil rejecter leaking gearbox oil out onto the prop.
BTW have you checked the torque on the bolts fixing the diff flange to the prop flange ?
It's said that previously the diff was quite quiet. We can eliminate the angle of the engine and/or diff, because as far as we have been told , this has never changed.
The main event that caused all the noise appears to be the rebuild of the diff. Therefore as I said before, I would start with replacing the oil with the recommended highest quality. If no change, return the diff to the rebuilder.
I would expect any prop misalignment, play or poor balance to cause terrible vibration and probably damage the gearbox rear oil rejecter leaking gearbox oil out onto the prop.
BTW have you checked the torque on the bolts fixing the diff flange to the prop flange ?
Bert.
If I write something you don't like. That doesn't make me a knob !
No. What it means is that you don't like what I wrote.
And because I write something you don't like, it doesn't make me wrong either.
If we were having this conversation across a table in a pub, it's unlikely you would call me ( or anyone ) a knob to their face.
I read all sorts of stuff on the net. Some highly intelligent and some dumb as fxxk. I would never talk down to or badly to anybody, no matter what. If you would like to debate with me on any subject....... Be my guest.
I'm sure you have had lessons in manners for people far closer to home, so I won't comment on the tone of your language as I assume you already know better.
If I write something you don't like. That doesn't make me a knob !
No. What it means is that you don't like what I wrote.
And because I write something you don't like, it doesn't make me wrong either.
If we were having this conversation across a table in a pub, it's unlikely you would call me ( or anyone ) a knob to their face.
I read all sorts of stuff on the net. Some highly intelligent and some dumb as fxxk. I would never talk down to or badly to anybody, no matter what. If you would like to debate with me on any subject....... Be my guest.
I'm sure you have had lessons in manners for people far closer to home, so I won't comment on the tone of your language as I assume you already know better.
the av8er said:
Your asking my to help, so here I am helping.
It's said that previously the diff was quite quiet. We can eliminate the angle of the engine and/or diff, because as far as we have been told , this has never changed.
The main event that caused all the noise appears to be the rebuild of the diff. Therefore as I said before, I would start with replacing the oil with the recommended highest quality. If no change, return the diff to the rebuilder.
I would expect any prop misalignment, play or poor balance to cause terrible vibration and probably damage the gearbox rear oil rejecter leaking gearbox oil out onto the prop.
BTW have you checked the torque on the bolts fixing the diff flange to the prop flange ?
There is a chance that the position of the diff has moved. The way it’s fitted is a bit HR, bolts needing to be hammered through, diff bolted to carrier, carrier bolted to diff. It's said that previously the diff was quite quiet. We can eliminate the angle of the engine and/or diff, because as far as we have been told , this has never changed.
The main event that caused all the noise appears to be the rebuild of the diff. Therefore as I said before, I would start with replacing the oil with the recommended highest quality. If no change, return the diff to the rebuilder.
I would expect any prop misalignment, play or poor balance to cause terrible vibration and probably damage the gearbox rear oil rejecter leaking gearbox oil out onto the prop.
BTW have you checked the torque on the bolts fixing the diff flange to the prop flange ?
I’ve been told the diff should be removed and replaced fully bolted into carrier, though given no reasons why. I didn’t do that, so there seems to be the chance it’s not in its original position. There certainly seems to be tolerance in bolts/holes to allow movement.
The diff has been rebuilt twice and to be fair is very quiet under power. It was done by the guy who’s supposed to be the best and it has his recommended oil in, which many rate as ‘magic’. For now, I think I’m going to assume this element is correct and look for something that I might have caused. But I will keep it in mind.
The rear box seal thing is interesting. It’s always leaked a little bit, which is not at all unusual. Just recently during this work it’s been worse, which I thought was down to moving the nose of the prop in and out of the box a little to clear the diff flange. Maybe not. It’s not bad, just the odd drop.
Yes, the prop bolts have been tightened correctly. I had a whole thread on the club forum just trying to confirm the correct figure, even asked CC. In the various manuals they have at least three different figures!
In my manual, it seems to be the only torque figure not listed.
My prop oil rejector seal also weeps very very slightly. It never drips, but after I long blat there is a slight smear along the underside of the floor. I feel that this is nothing to worry about. Though at some point I will replace it.
If you think you have altered the position of the diff, slacken off the bolts and see how much movement you have to play with.
Definitely worth a go but not sure that's the problem.
May sound daft, but have you checked the tyre pressures across the rear axle. If they are not equal this will effect the dif......
Or if you have directional tyre, is 1 fitted the wrong way round ?
Just a thought.
My prop oil rejector seal also weeps very very slightly. It never drips, but after I long blat there is a slight smear along the underside of the floor. I feel that this is nothing to worry about. Though at some point I will replace it.
If you think you have altered the position of the diff, slacken off the bolts and see how much movement you have to play with.
Definitely worth a go but not sure that's the problem.
May sound daft, but have you checked the tyre pressures across the rear axle. If they are not equal this will effect the dif......
Or if you have directional tyre, is 1 fitted the wrong way round ?
Just a thought.
the av8er said:
In my manual, it seems to be the only torque figure not listed.
My prop oil rejector seal also weeps very very slightly. It never drips, but after I long blat there is a slight smear along the underside of the floor. I feel that this is nothing to worry about. Though at some point I will replace it.
If you think you have altered the position of the diff, slacken off the bolts and see how much movement you have to play with.
Definitely worth a go but not sure that's the problem.
May sound daft, but have you checked the tyre pressures across the rear axle. If they are not equal this will effect the dif......
Or if you have directional tyre, is 1 fitted the wrong way round ?
Just a thought.
My prop oil rejector seal also weeps very very slightly. It never drips, but after I long blat there is a slight smear along the underside of the floor. I feel that this is nothing to worry about. Though at some point I will replace it.
If you think you have altered the position of the diff, slacken off the bolts and see how much movement you have to play with.
Definitely worth a go but not sure that's the problem.
May sound daft, but have you checked the tyre pressures across the rear axle. If they are not equal this will effect the dif......
Or if you have directional tyre, is 1 fitted the wrong way round ?
Just a thought.
Tyre pressures and direction are fine.
Well, for those who are interested, I believe I’ve got to the bottom of this.
The CWP assembly has been damaged by the carbon plate Titan LSD breaking up. (After 8000 miles)
According to CC “it wouldn’t be uncommon In the past to see the crown wheel and pinion become damaged, most commonly caused by the carbon particles from the worn clutch plates eating into the internal surfaces”
CC have also told me that the LSD requires regular servicing which, I’m told, amounts to rebuilding every few thousand miles and keeping a close check on preload during those miles. If the preload falls, rebuild the LSD.
The CW&P aren’t available as parts, BMW won’t sell them to CC, so if you need to replace you have to buy a new open diff at £1300.
My diff is being again overhauled with special attention to polishing up and removing any burrs or marks on the CWP. If that doesn’t work I’m stuck with buying a new open diff.
There is another option, at even more expense, that I’ve considered. It would require another £1500 but would avoid paying £5/600 every few years on Titan rebuilds.
I shall be back..........
The CWP assembly has been damaged by the carbon plate Titan LSD breaking up. (After 8000 miles)
According to CC “it wouldn’t be uncommon In the past to see the crown wheel and pinion become damaged, most commonly caused by the carbon particles from the worn clutch plates eating into the internal surfaces”
CC have also told me that the LSD requires regular servicing which, I’m told, amounts to rebuilding every few thousand miles and keeping a close check on preload during those miles. If the preload falls, rebuild the LSD.
The CW&P aren’t available as parts, BMW won’t sell them to CC, so if you need to replace you have to buy a new open diff at £1300.
My diff is being again overhauled with special attention to polishing up and removing any burrs or marks on the CWP. If that doesn’t work I’m stuck with buying a new open diff.
There is another option, at even more expense, that I’ve considered. It would require another £1500 but would avoid paying £5/600 every few years on Titan rebuilds.
I shall be back..........
Do you really need to have an LSD?
Why not fit a standard diff ? Obviously there will be a difference in handling and feel, but just as much fun or maybe more.
I don't have an LSD and have no problems, no noise, no hassle and all the fun.
I can hold a conversation in my car without raising my voice (with weather gear fitted) and the handling is great !!
If your car is excessively noisy and your constantly worried about reliability it must effect your enjoyment in a negative way. Is it really worth the agro ??
Why not fit a standard diff ? Obviously there will be a difference in handling and feel, but just as much fun or maybe more.
I don't have an LSD and have no problems, no noise, no hassle and all the fun.
I can hold a conversation in my car without raising my voice (with weather gear fitted) and the handling is great !!
If your car is excessively noisy and your constantly worried about reliability it must effect your enjoyment in a negative way. Is it really worth the agro ??
You have my sympathies
I have now had two caterhams with faulty diffs due to the carbon plates. The first one was repaired in warranty by caterham (although i has to pay the labour for its removal/reffitting) and second time had to bear the full cost even after the caterham salesman had assured me the car didnt have the carbon plates fitted. They were clearly a design fault and Caterham should have to bear the cost of these issues but they dont.
The second time, the carbon breaking down caused the gear to whine badly requiring a refurbished replacement with new gears and sintered plates.
The suggestion to go to an open diff is a fair shout, im not sure how necessary an lsd really is. I have a 420R and regularly track it and strongly suspect i dont need an lsd
I have now had two caterhams with faulty diffs due to the carbon plates. The first one was repaired in warranty by caterham (although i has to pay the labour for its removal/reffitting) and second time had to bear the full cost even after the caterham salesman had assured me the car didnt have the carbon plates fitted. They were clearly a design fault and Caterham should have to bear the cost of these issues but they dont.
The second time, the carbon breaking down caused the gear to whine badly requiring a refurbished replacement with new gears and sintered plates.
The suggestion to go to an open diff is a fair shout, im not sure how necessary an lsd really is. I have a 420R and regularly track it and strongly suspect i dont need an lsd
Thanks for the replies.
I’m a little surprised that an open diff has been suggested. Before the diff came out, when the LSD wasn’t working, the car was a real handful under power accelerating hard in lower gears.
If one wheel hit a bump, or accelerating hard out of a corner, it would easily start to slide or fishtail. As soon as the LSD was rebuilt that all stopped, which is what I would expect.
Easily avoidable on the road, keeping a light foot, but I doubt it would be much fun on track. I dread to think what it would be like with one wheel up on a kerb.
I’ve considered a Quaife but think there may be a better option. Watch this space
I’m a little surprised that an open diff has been suggested. Before the diff came out, when the LSD wasn’t working, the car was a real handful under power accelerating hard in lower gears.
If one wheel hit a bump, or accelerating hard out of a corner, it would easily start to slide or fishtail. As soon as the LSD was rebuilt that all stopped, which is what I would expect.
Easily avoidable on the road, keeping a light foot, but I doubt it would be much fun on track. I dread to think what it would be like with one wheel up on a kerb.
I’ve considered a Quaife but think there may be a better option. Watch this space
kev b said:
Just poking my nose in here as I have never even sat in a Caterham but theres been no mention of propshaft balance, from what I glean from this thread regarding QC at CC it could be worth checking?
No. Propshaft is fine. I am close to telling you what the issue was and what the solution is. Just not quite ready. Soon.
Just read through this thread... My K series R300 was a little clunky, but eventually I learned the throttle control to minimise it.
It never really bothered me that much being an open car.
I suppose the answer is to shim the diff yourself. You can buy shims of various sizes and thicknesses from bearing suppliers.
It never really bothered me that much being an open car.
I suppose the answer is to shim the diff yourself. You can buy shims of various sizes and thicknesses from bearing suppliers.
mickrick said:
Just read through this thread... My K series R300 was a little clunky, but eventually I learned the throttle control to minimise it.
It never really bothered me that much being an open car.
I suppose the answer is to shim the diff yourself. You can buy shims of various sizes and thicknesses from bearing suppliers.
My issue was far more than being a little clunky, Mick. It never really bothered me that much being an open car.
I suppose the answer is to shim the diff yourself. You can buy shims of various sizes and thicknesses from bearing suppliers.
However, I’ve learned an awful lot over the last few months, things are a lot clearer.
Gassing Station | Caterham | Top of Page | What's New | My Stuff