Gearbox failed 18 months after garage work - what to do?
Discussion
(Bit of a complicated post, so apologies - and if it's in the wrong place, apologies on that front as well.)
My gearbox was fitted with an aftermarket limited slip diff by a reputable-looking garage 18 months ago, in August 2018.
About 100 miles ago I noticed a metallic knocking in first, third and fifth gears, particularly whilst accelerating - even gently.
About 10 miles ago I started hearing a fairly loud knocking noise a bit like something catching the wheelarch liner when making left turns, particularly at low speed with a bit of throttle applied.
At this point I limped the car home.
On getting the car up in the air, I found that the front-left driveshaft won't rotate more than a fraction of a mm in either direction, while the right rotates freely.
There are no puddles of transmission oil under the car, or any other signs which might indicate a catastrophic failure.
Drive from the engine is still being sent to the freely-rotating wheel; the wheel spins when all the wheels are in the air and the car is in gear with the engine running.
My working assumption at this point is that the left driveshaft side of the diff has seized.
So, should I ask if the garage who did the original work would be prepared to get the gearbox off and find the cause of the problem? (I wouldn't expect them to work for free, but I would hope if they found something which was clearly their mistake they might own up to it...)
Or, should I ask an independent garage to take a look, on the basis that the first garage might have carried out poor work which could have caused this?
I guess for me the bottom line is, should I trust a garage who may or may not have done a poor job in the first place to put things right - or, from the other point of view, if it's just rotten luck and a part has failed somehow, why wouldn't I trust the work to fix it to the garage who worked on the gearbox previously?
(In case it helps to paint a picture, Shed has a fancy dual clutch gearbox and one of the dual clutches is mated to an input shaft which looks after 1st, 3rd and 5th gear cogs. I'm wondering if the knocking in 1, 3 and 5 might be a red herring and not directly related to the seized driveshaft.)
Yours confusedly,
Alex
My gearbox was fitted with an aftermarket limited slip diff by a reputable-looking garage 18 months ago, in August 2018.
About 100 miles ago I noticed a metallic knocking in first, third and fifth gears, particularly whilst accelerating - even gently.
About 10 miles ago I started hearing a fairly loud knocking noise a bit like something catching the wheelarch liner when making left turns, particularly at low speed with a bit of throttle applied.
At this point I limped the car home.
On getting the car up in the air, I found that the front-left driveshaft won't rotate more than a fraction of a mm in either direction, while the right rotates freely.
There are no puddles of transmission oil under the car, or any other signs which might indicate a catastrophic failure.
Drive from the engine is still being sent to the freely-rotating wheel; the wheel spins when all the wheels are in the air and the car is in gear with the engine running.
My working assumption at this point is that the left driveshaft side of the diff has seized.
So, should I ask if the garage who did the original work would be prepared to get the gearbox off and find the cause of the problem? (I wouldn't expect them to work for free, but I would hope if they found something which was clearly their mistake they might own up to it...)
Or, should I ask an independent garage to take a look, on the basis that the first garage might have carried out poor work which could have caused this?
I guess for me the bottom line is, should I trust a garage who may or may not have done a poor job in the first place to put things right - or, from the other point of view, if it's just rotten luck and a part has failed somehow, why wouldn't I trust the work to fix it to the garage who worked on the gearbox previously?
(In case it helps to paint a picture, Shed has a fancy dual clutch gearbox and one of the dual clutches is mated to an input shaft which looks after 1st, 3rd and 5th gear cogs. I'm wondering if the knocking in 1, 3 and 5 might be a red herring and not directly related to the seized driveshaft.)
Yours confusedly,
Alex
You don’t say how much you have used the car over the 18 months. What age / mileage is the car and gearbox. Modifications always carry a risk re their impact on other components. Sounds like the extra loads of an LSD may have been too much for the gearbox.
You have nothing to lose by going back to the lsd installer. They may have experience of similar issues. Unfortunately I don’t think you can expect much else from them.
You have nothing to lose by going back to the lsd installer. They may have experience of similar issues. Unfortunately I don’t think you can expect much else from them.
What criteria for your use to choose the garage in the first place? I presume some confidence that they had the right expertise to take a gearbox apart, fit the LSD and put it back together?
If you still have confidence take it back. If not go elsewhere to someone who you are confident in.
It's pretty simple.
Bert
If you still have confidence take it back. If not go elsewhere to someone who you are confident in.
It's pretty simple.
Bert
alexmonkey said:
...My gearbox was fitted with an aftermarket limited slip diff by a reputable-looking garage 18 months ago, in August 2018.
That probably puts it beyond any kind of warranty repair, I would think.alexmonkey said:
About 100 miles ago I noticed a metallic knocking in first, third and fifth gears, particularly whilst accelerating - even gently.
If it's only in those gears, that suggests that it's not the diff. The diff has no idea what gear you're in.alexmonkey said:
About 10 miles ago I started hearing a fairly loud knocking noise a bit like something catching the wheelarch liner when making left turns, particularly at low speed with a bit of throttle applied.
That sounds more like a CV joint problem as does this...alexmonkey said:
On getting the car up in the air, I found that the front-left driveshaft won't rotate more than a fraction of a mm in either direction, while the right rotates freely.
alexmonkey said:
So, should I ask if the garage who did the original work would be prepared to get the gearbox off and find the cause of the problem? (I wouldn't expect them to work for free, but I would hope if they found something which was clearly their mistake they might own up to it...)
Sounds like a plan.alexmonkey said:
I'm wondering if the knocking in 1, 3 and 5 might be a red herring and not directly related to the seized driveshaft.)
I struggling to believe that the two are related myself. It is feasible that perhaps a piece has chipped off a gear tooth and has now dropped into the diff and busted something properly, but I can't think that a DSG box would have one gear pinion in common with 1-3-and 5th gear. Could be a bearing on that shaft, I suppose.Sounds like a strip and check exercise anyway.
Im assuming this vehicle is a VAG group product with 7 speed DSG box, twin plate clutches and dual mass flywheel. If I remember correctly there is definately a connection between 1st, 3rd and 5th, the mechatronic has 3 solenoids one controls 1st,3rd and 5th, one 2and 6 and the other 4th and 7th I think.
The o/s driveshaft is the longest and in my experience will always spin more freely than the short n/s but not to the extent of your problem, there would definately appear to be something odd happening there.
Your knocking noise could possibly be the dual mass flywheel worn out although you would normally hear that at idle when stationery. I have seen cases with VWs where the engine would lock up due to a badly worn flywheel but Ive never heard of it affecting the gearbox.
The o/s driveshaft is the longest and in my experience will always spin more freely than the short n/s but not to the extent of your problem, there would definately appear to be something odd happening there.
Your knocking noise could possibly be the dual mass flywheel worn out although you would normally hear that at idle when stationery. I have seen cases with VWs where the engine would lock up due to a badly worn flywheel but Ive never heard of it affecting the gearbox.
You don't say how much use the vehicle has had since the LSD was installed but as someone who has been well into modifying cars myself over the years I think you are going to be facing an uphill battle to get the garage to take blame on the face of it.
I wonder did the garage supply the LSD or did you supply your own parts?
I wonder did the garage supply the LSD or did you supply your own parts?
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