Steering from the rear... And not in a good way!!!
Discussion
Anyone got any ideas? It's a strange one...
It happens majority of the time when I am driving on a motorway or A-road at speed. It does happen at other times but not often.
As I am driving the rear drifts off to the left and then with a heavy 'jolt' bangs back straight again!! As you can imaging it can be quite hairy.
Sometimes its minor but others can be quite a long (well it seems long) slide (cant think of a better word!) before it snaps back inline.
The shocks have been changed, as far as I can see the chassis is ok the main diff bush was replaced last year. The diff bush bracket is a few years old but was ok when the bush was changed. Diff oil checked but not replaced. The other bushes were checked at a recent MOT but not ruling these out completely.
It could be the diff itself but as it happens when I am driving in a straight line I cant see why it would be but again not ruling it out!
Anybody got any ideas?
It happens majority of the time when I am driving on a motorway or A-road at speed. It does happen at other times but not often.
As I am driving the rear drifts off to the left and then with a heavy 'jolt' bangs back straight again!! As you can imaging it can be quite hairy.
Sometimes its minor but others can be quite a long (well it seems long) slide (cant think of a better word!) before it snaps back inline.
The shocks have been changed, as far as I can see the chassis is ok the main diff bush was replaced last year. The diff bush bracket is a few years old but was ok when the bush was changed. Diff oil checked but not replaced. The other bushes were checked at a recent MOT but not ruling these out completely.
It could be the diff itself but as it happens when I am driving in a straight line I cant see why it would be but again not ruling it out!
Anybody got any ideas?
If the rear suspension is secure I can't see how the diff moving would cause it to steer. Clunk and bang, certainly but the wheels wouldnt move. I would have a look at the toe adjusters on the lower rear suspension arms - if the lock nut has come loose or the pin has broken then the wheel would be free to move under load.
As far as I can tell the front diff brackets are ok! But I know looks can be very deceptive. I have got the bushes to replace the front ones but after inspecting them a short while ago didn't feel they looked like they needed doing but again looks can be deceptive!
"I would have a look at the toe adjusters" hmm certainly something I have not looked at so worth checking out are they easily to spot from under the car? I did also recently have all my shocks changed.. the problem was there before and also after this so was keeping my eyes open for anything suspect.
The diff mounting bracket has been checked twice and the bush changed. In fact last time it was checked was because on of the bolts had sheered in it which is very very odd!!!
"I would have a look at the toe adjusters" hmm certainly something I have not looked at so worth checking out are they easily to spot from under the car? I did also recently have all my shocks changed.. the problem was there before and also after this so was keeping my eyes open for anything suspect.
The diff mounting bracket has been checked twice and the bush changed. In fact last time it was checked was because on of the bolts had sheered in it which is very very odd!!!
Mark - I'd take the car to a Wheel allignment place and get that checked out. You can do some rough measurements at home first with a bit of string, which may show something up if is 'well' out. Measure from the centre of the wheels front to back, and underneath the car do some diagonal measurements from points along the chassis.
The rear toe adjusters are where the front of the lower suspension arm pivots on the chasis. There is a threaded rod that is mounted to the chasis with a bush and this fits into a tube with a threaded insert on the suspension arm. There is a lock nut on the end of the rod that holds the whole thing together.
I would put it up on stands, take the back wheels off and grab the front edge of the lower suspension arm and give it a good tug with my feet braced against the chasis. If there is any movement at all I suspect that you have lost a lock nut and may be the cause of the problem.
I would put it up on stands, take the back wheels off and grab the front edge of the lower suspension arm and give it a good tug with my feet braced against the chasis. If there is any movement at all I suspect that you have lost a lock nut and may be the cause of the problem.
The car has been involved in an accident but that was before I got it and I've had it over 5 years now!
Alignment would also tie in with what Peter is saying.. I know the adjusters you are talking about now. I did change one of the bushes in one a while back (when I started having this issue) thinking that might be the cause, but it wasn't! Thats when I discovered one of the diff bracket bolts had sheared!
Definitely worth another look at these adjusters just in case!!
It's not something that is permanently out of align because sometimes I can drive with no problems what so ever but then other times it makes for a hell of a tense ride lol
Alignment would also tie in with what Peter is saying.. I know the adjusters you are talking about now. I did change one of the bushes in one a while back (when I started having this issue) thinking that might be the cause, but it wasn't! Thats when I discovered one of the diff bracket bolts had sheared!
Definitely worth another look at these adjusters just in case!!
It's not something that is permanently out of align because sometimes I can drive with no problems what so ever but then other times it makes for a hell of a tense ride lol
The toe adjusters hark back to '71 in their design on the TVR....a common error in bolting the bush eye (suspension pin tracking adjusting) part of these into the male threaded part (track adjusting sleeve) and adding a washer which locks locks out on the thread of the wishbone which is the female part, this allows a gap between the sleeve and the head of the nut which slowly attempts to punch the washer through down the thread and leaves the bush eye loose...it might be worth a look.
Adrian@
Adrian@
Adrian is there another way you can explain that? sorry my brain must be fried due to all the sun past two days lol
When I changed the bush (near side) I didn't undo the 'unit' but through being belted, to pop the bush out, it did start turning but it wasn't the thread itself but the bush housing as it joins to the threaded section. If that makes sense lol
When I changed the bush (near side) I didn't undo the 'unit' but through being belted, to pop the bush out, it did start turning but it wasn't the thread itself but the bush housing as it joins to the threaded section. If that makes sense lol
Adrian@ said:
The toe adjusters hark back to '71 in their design on the TVR....a common error in bolting the bush eye (suspension pin tracking adjusting) part of these into the male threaded part (track adjusting sleeve) and adding a washer which locks locks out on the thread of the wishbone which is the female part, this allows a gap between the sleeve and the head of the nut which slowly attempts to punch the washer through down the thread and leaves the bush eye loose...it might be worth a look.
Adrian@
In simple terms Adrian@
Think that wishbone/threaded adjuster and locknut as a complete unit.... this has a bush eye , which is held on by a 1/2UNF nut (going through the threaded adjuster), IF when this is built up a washer that is too large under that nut, then it locks onto the first thread of the wishbone rather than locking up onto the adjuster ....in motion the loads will push and pull these in and out acting like a hammer driver.
Checking that there is no washer OR the right size washer is in there, also rolling the car forward then looking for a gap between the bush eye and adjuster AND do the same rolling the car backwards.
Adrian@
I have never seen a pictorial factory procedure for the later cars on adjusting rear toe, (there is one for the early cars on the TVRCC site archives which is identical in design) but I've seen this fault through out my TVR life.
Edited by Adrian@ on Sunday 23 May 19:44
Just an update on this .... Still no joy by the way!
A bit of a delay in this because I had an op to repair a broken collar bone.
Well I completely removed the toe in adjusters inspected them and replaced them. Whilst tightening them up I watched the gap close up so I knew they were tight according to me tightening them. (That kinda makes sense lol)
Also I checked again the diff bracket and all was fine!
Whilst the rear wheels were both off the ground and both inner lower wishbone bolts (one being the toe in adj) were removed I tried to feel for any unusual play and found nothing wrong that I could tell anyway.
Could the Diff really cause this? Its the kind of problem that if I take it to a specialist and go for a test drive it wont do it and i am reluctant to rip out the diff until convinced it is the cause. I hear they are not the easiest things to remove!!
A bit of a delay in this because I had an op to repair a broken collar bone.
Well I completely removed the toe in adjusters inspected them and replaced them. Whilst tightening them up I watched the gap close up so I knew they were tight according to me tightening them. (That kinda makes sense lol)
Also I checked again the diff bracket and all was fine!
Whilst the rear wheels were both off the ground and both inner lower wishbone bolts (one being the toe in adj) were removed I tried to feel for any unusual play and found nothing wrong that I could tell anyway.
Could the Diff really cause this? Its the kind of problem that if I take it to a specialist and go for a test drive it wont do it and i am reluctant to rip out the diff until convinced it is the cause. I hear they are not the easiest things to remove!!
No not losing traction. It happens at pretty much any given time more noticeably, and commonly and scarealy (is that a made up word? lol) while cruising and in straight line until the rear drifts off to the left then with a jolt goes straight again.
Naturally my A road and M way journeys now are very very limited. Imagine a spring winding up then letting go!!
I have felt the 'jolt' (best word to describe it) even at very slow speeds parking manoeuvres but not the drifting as there is no speed involved! And it doesn't seem to be related to any turning either!!
I have spun the wheels by hand and they felt fine as far as I can tell the hydratrack is as it should be but whats the lumpiness you mention? I will have another check for this?
Naturally my A road and M way journeys now are very very limited. Imagine a spring winding up then letting go!!
I have felt the 'jolt' (best word to describe it) even at very slow speeds parking manoeuvres but not the drifting as there is no speed involved! And it doesn't seem to be related to any turning either!!
I have spun the wheels by hand and they felt fine as far as I can tell the hydratrack is as it should be but whats the lumpiness you mention? I will have another check for this?
The wheel should be hard to turn, as it turns you should feel it turn easier and then harder again, something to do with the viscous LSD doing its stuff.
I dont think its the diff though.
It sounds like you have maybe a broken chassis
or maybe even your brakes doing some strange stuff?
Who changed the top diff mount bush? These are an absolute t
t to remove and if they tried to hammer it out its possible they could of broken the welds to the chassis.
As Gazzab says get it to a good indie or get in on ramps, get the exhausts off and have a good look yourself at the chassis.
I dont think its the diff though.
It sounds like you have maybe a broken chassis
or maybe even your brakes doing some strange stuff?Who changed the top diff mount bush? These are an absolute t
t to remove and if they tried to hammer it out its possible they could of broken the welds to the chassis. As Gazzab says get it to a good indie or get in on ramps, get the exhausts off and have a good look yourself at the chassis.
Well thats the thing! Most of them are quite a distance and I know that when I do go for a spin with them it will behave itself!! Sods law that. I have been hampered myself in what I can do recently including driving it due to a broken collar bone.
I will have to take it somewhere soon and get an opinion.
I will have to take it somewhere soon and get an opinion.
It could be the chassis. They can break due to poor welds, rot or metal fatigue. Particularly if they have had accident repairs and a weakness not spotted etc Could there have been a chassis repair, some sleeving etc? soounds like that something is moving - either the chassis or the diff....?
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