knocking noise from the rear
Discussion
Starting to get fed up with this now. Had the diff out found a possible rear bush and carrier issue got a beefed up carrier from Adrian and new rear bushes. Checked all the drive shafts hubs prop etc pulled the back of the diff and checked all the brearings and gears and all good just got it all back together tonight and test diven and exactly the same power on clunk clunk clunk power off all quiet more noticeable when going up hill but can't hear it when on full power. Can't really feel it no vibrations sounds a bit like a dull UJ sound but they are all new and fine. No idea what to look at now. May have to just put up with it until it either disappears or gets a lot worse but does take the shine out of driving it.
Chris
Chris
I had a similar clunk particularly when taking up power or coming off power. After numerous diff changes it turned out to be a worn driveshaft spline. I had looked at UJ's and they were ok and only later looked at splines - movement was minimal but still noticeable when doing it by hand but the tiny click was enough to resound when driving to give a loud almost thump type noise.
Any use?
Any use?
V6Pushfit said:
I had a similar clunk particularly when taking up power or coming off power. After numerous diff changes it turned out to be a worn driveshaft spline. I had looked at UJ's and they were ok and only later looked at splines - movement was minimal but still noticeable when doing it by hand but the tiny click was enough to resound when driving to give a loud almost thump type noise.
Any use?
Cheers for the advice but I did try this and did find one that had a small amount of play in so replaced it but made no difference. It was suggested earlier that it may be further forward I have checked the gearbox mounting and engine mounts also the exhaust. Clutch feels fine checked all bellhousing bolts as well. Handbrake cables aren't touching anything plus if you put the handbrake on while drivingitmakes no difference to the sound. No idea where to go next. Was thinking of driving down to BHP on Sunday but not sure I dare risk it. It must be something Any use?
bluezeeland said:
- Rear hubs to upright bolts ?
-lower rear uprights to wishbone pin ?
-g/b rear mount ?
-engine mounts ?
All checked and good I think it must be internal on the diff. I have another diff on its way a known good one so will try this. If this doesn't work then I will have to admit to being beat and see if it get worse which will help find the fault.-lower rear uprights to wishbone pin ?
-g/b rear mount ?
-engine mounts ?
Thanks for the help Chris
TVR Beaver said:
I mean.. it's that loud isn't it 
It's one of those noises that just spoils your driving as your always listening for it. Your right it isn't loud and most of the time you can't hear it above the exhaust and road noise, but it's there and needs sorting. New diff now acquired so will be fitting it over the weekend. This diff has a lot less free play on the prop pinion so may be that the guy who rebuilt mine didn't do a good job or missed something he was recommended by other Tvr guys that have had them rebuilt by him with no issues. He also rebuilt the Vixen diff so hopefully that will be ok.
Chris
chris52 said:
It's one of those noises that just spoils your driving as your always listening for it. Your right it isn't loud and most of the time you can't hear it above the exhaust and road noise, but it's there and needs sorting.
New diff now acquired so will be fitting it over the weekend. This diff has a lot less free play on the prop pinion so may be that the guy who rebuilt mine didn't do a good job or missed something he was recommended by other Tvr guys that have had them rebuilt by him with no issues. He also rebuilt the Vixen diff so hopefully that will be ok.
Chris
I hope it wasn't the guy that did mine and then when it made noises this was in it from the drain hole he drilled after rebuilding:New diff now acquired so will be fitting it over the weekend. This diff has a lot less free play on the prop pinion so may be that the guy who rebuilt mine didn't do a good job or missed something he was recommended by other Tvr guys that have had them rebuilt by him with no issues. He also rebuilt the Vixen diff so hopefully that will be ok.
Chris
Edited by V6Pushfit on Wednesday 20th April 09:50
Before fitting the replacement diff as it needs a new front oil seal which is on its way to me I decided to do some measuring of the backlash on the diff. DTI gauge on the ring gear and measured the free play. Triumph quote 0.004" to 0.006". The one that I had rebuilt was 0.0118". The second hand one that I have just bought the backlash 0.0055 so within tolerance. I don't know if this will cause the noise I cant find anything else wrong with it but this is pretty disappointing to say that a well known rrecommended axle specialist would allow this to come out of there workshop like this.
Would appreciate any opinions on what basically double the backlash will do and if it's possible this will be the cause of the noise.
Chris
Would appreciate any opinions on what basically double the backlash will do and if it's possible this will be the cause of the noise.
Chris
When I've done diffs in the past, I've always 'blued' them up and with pressure on the outputs, tried to get the contact area towards the back of the tooth (depending which way you look), so when it comes under more presure, it tends to drive central... you shim it to get this....
with that much play on and off power, it will move too much over the contact area on the tooth I would have thought.... so assuming he's set it central on power.. it will move right off the area when off power (or over-run)
but even then... it still does not explain why it knocks?....
try the new one is all you can do... hope it fixes the problem...
Did someone mention splines??..
with that much play on and off power, it will move too much over the contact area on the tooth I would have thought.... so assuming he's set it central on power.. it will move right off the area when off power (or over-run)
but even then... it still does not explain why it knocks?....
try the new one is all you can do... hope it fixes the problem...
Did someone mention splines??..
We changed the diff in the Taiamr as the backlash was too much, but it didn't knock constantly, it was only a clunk when coming onto and off the power if your weren't silky smooth.
The diff was also checked over by a decent place with a new front seal installed.
Even the replacement one, which is a used one still, has a small clunk sometimes at power on, but it's much much better than the old one.
The diff was also checked over by a decent place with a new front seal installed.
Even the replacement one, which is a used one still, has a small clunk sometimes at power on, but it's much much better than the old one.
chris52 said:
Replaced the diff and the noise has now gone so must have been something in the diff. I have sent it back to the rebuilders to find out what was up with it and get it sorted as I will put it back in the car at some point as the one in now has a small oil leak.
Chris
Glad its sorted Chris look forward to seeing her out motoring Chris
Andrew
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