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the car gives a wiggle changing gear


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I have an idea that this is due to rear suspension arm bushes needing replaced.

sometimes while changing gear on a fast long bend the car gives a funny wiggle. Unsettles the car briefly and is slightly worrying. It's more noticeable at speed.

I believe my chassis is fine. tires are good, shocks and springs nearly new. Thinking It through my minds eye is seeing the rear arm , the big alloy bugger, moving and causing it. Would this be something someone else has experienced? If I told you the bushes have not been changed in 18 years you may just laugh.

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Hi Murray Arnold, well described as wiggle, i have the same "wiggle" and have already had it diagnosed as trailing arm bushes,i have bought some polybushes ready to fit this winter....

Have fun

Conrad.

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I get this too, and I have assumed that the drive shaft splines were locking up under torque.The wiggle always occurs on the first gear change after accelerating strongly out of a corner, at which time the splines move back to their "normal" position and the rear suspension settles.

 

Bryan

New Zealand

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I get this too, and I have assumed that the drive shaft splines were locking up under torque.The wiggle always occurs on the first gear change after accelerating strongly out of a corner, at which time the splines move back to their "normal" position and the rear suspension settles.

 

Bryan

New Zealand

Bryan, Yes. Mine used to the lock up in a tight corner accelerating hard, and released with a wiggle the instant I lifted off to change gear. I cured mine with liberal molygrease on the drive shaft splines. Peter

Edited by Peter Cobbold
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Similar to Bryan and Peter, mine used to do a little shimmy on the first change accelerating after a corner. If I was accelerating hard I'd describe it as more of a hop. Not good. I had the half-shafts replaced with a mod using Datsun drive shafts. That solved it. Since then I've put in polybushes all round (standard stiffness though) and that tightened up the handling wonderfully.

Cheers,

John

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As I suspected. well apart from the spline issue. So just another typical tr nuance. wow, it does have a few of them, ha. But I still love it. So basically remove the trailing arm and drive shafts, grease the shafts up and renew all bushes. Easy job with the correct tools. The problem with this issue is when unexpected, it's easy to over react and end up on the other side of a hedge. Ok winter work.

Thanks guys for confirming this.

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If you think an IRS TR is bad for this you ought to try a Stag !!! famously called the Stag twitch. The lubing of the splines on the driveshafts work temporarily but after 5-6 months driving the twitch comes back. CV joints or the Datsun driveshafts cure it permanently and I'm yet to do my Stag.

 

Mick Richards

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Brings back memories of my TR4, in the 1960's, with it's solid back axle...it used to hop around corners!

Wish I kept it in hindsight and not the TR6, as it was a lot more fun and far more reliable!...I'll get my coat! :huh:

Edited by Denis
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I have to say for tarmac regular road use I see the old English axle as perfectly acceptable. In my opinion IRS is only beneficial for rough road. And I mean look at all the race success that mk1 and 2 escorts had with a live axle.

At the end of the day its personal choice. And I really cant see many 6 owners reverting from IRS to a live axle. That's just not cricket some would say.

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Yes the famous Stag "twitch" is not only for the Stag but due to the same rear susp & trans architecture, also for the TR4A irs, TR5, 250 & 6..

 

Note/ Stag: Unfortunately for the Stag the Datsun driveshafts are not any more available (as fare as I experienced this summer) and the only real option is the upgraded design of the drive shaft but very expensive. Finaly, I used the Rilsan upgraded drive shafts and after 3000 Km this summer it is still good.... so fare. I shall check if the same option is available for the TR6.

 

Regards

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Marc,

 

Monarch Stag I believe still offer the Datsun driveshafts, and I've see 2 used pairs off Datson 180y available on e bay in the last 2 months, (America though).

 

Mick Richards

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Mick Richards,

 

I was in contact w/ Monarch Stag in May/june but the Datsun driveshafts reconditioned was not anymore available and I select a GKN wIth rislan expoxu coated splines and for your information It works very well. Certainly a good and not too expensive option for the TR6 also.

 

Regards

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This drive shaft thing is all a new concept for me. I plan to renew my bushes. Is renewing the drive rices with a retro mod realy an option. Basically what's the cost benefit ratio and is this a straight forward bolt on

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Mine were a straight bolt-on. As for cost-benefit, they were the right answer for me. They solved that worrying shimmy, which had given me a couple of interesting moments. At the time (10+ years ago?) the originals were not available, and nor were the GKN alternatives (or the latter might have been but v pricey). BTW I think they use non-standard UJs. Not sure as I got my local specialist to do the UJs last time they needed replacing.

Cheers,

John

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This drive shaft thing is all a new concept for me. I plan to renew my bushes. Is renewing the drive rices with a retro mod realy an option. Basically what's the cost benefit ratio and is this a straight forward bolt on

The wiggle is nothing to do with the bushes. Duirng accleration in a bend the unlubricated drive shaft on the outside of the bend 'shortens' with body roll and spring compression. The unlubricated shaft holds that attitude until the torque on it is released when you lift off to change gear. The shaft relengthens and the spring extends and the body roll reverses - that the wriggle you feel.

 

The cure is to lubricate the sliding splines with molygrease ( MS2). I do that whenver a UJ needs replacing. But you might be able to do it with the shafts on the car. Clean off the inner end of the rubber boot and squirt molygrease in there from a gun, liberally. Ziplock to reseal the sleeve.

Edited by Peter Cobbold
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As per my post the lubrication improvement tends to be temporary, the friction scrapes it off again.

 

Mick Richards

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As per my post the lubrication improvement tends to be temporary, the friction scrapes it off again.

 

Mick Richards

I didn't find that. With the halves separated I used a toothbursh to work the moly onto the surfaces. Mind you the suspension is now so stiff there's little roll now, so they might be sticking. And they are around 150k old so wear might help keep them from sticking too.

Peter

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Mine had a little step on the shafts where they had worn away where they had spent most of their time.

 

Can someone refresh my memory though, wasnt it discussed about swapping the stubs around (so slide LHS inner, into RHS outer or even swap the whole thing around LHS to RHS and vice versa) so that the normally unloaded side of the spline (and unworn side) became the loaded side?

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