Car veers to the left when changing gear ??

[kev.w]

Hello,

 

Just fitted a Koni Shocks rear suspension upgrade (s/hand) and apart from finding the ride now too hard, I have noticed today, that when changing up from 3rd to 4th gear, on occation my TR4A veers quite sharply (under acceleration between gears) to the left. I dont know if its just coincidence, but do you think the shocks conversion has anything to do with it, or maybe its highlighted another problem ? I'm on standard everything apart from the shock kit.

 

Thanks for any advice.

 

Kev.w

[bob-menhennett]

Kev

Perhaps a little more detail, for budding Sherlock Holmes', might shed some light on the problem.

Was it just the shocks themselves that were second hand ?

A matching pair ?

Did they both seem to provide the same sort of resistance manually before you fitted them to the car ?

Any adjustment ...equal on both shocks ?

New mounting rubbers or the second hand ones that came with the shocks ?

Did the rubbers look serviceable, if second hand ?

No oil leaks from the shocks now that you have put them under load ?

No other work carried out to the rear of the car at the same time ?

No obvious loose bolts on suspension/ drive train ?

Tyre pressures checked ?

Braking is presumably "normal" i.e. no deviation from a straight line when brakes applied ?

 

Bob

[kev.w]

Kev

Perhaps a little more detail, for budding Sherlock Holmes', might shed some light on the problem.

Was it just the shocks themselves that were second hand ?

A matching pair ?

Did they both seem to provide the same sort of resistance manually before you fitted them to the car ?

Any adjustment ...equal on both shocks ?

New mounting rubbers or the second hand ones that came with the shocks ?

Did the rubbers look serviceable, if second hand ?

No oil leaks from the shocks now that you have put them under load ?

No other work carried out to the rear of the car at the same time ?

No obvious loose bolts on suspension/ drive train ?

Tyre pressures checked ?

Braking is presumably "normal" i.e. no deviation from a straight line when brakes applied ?

 

Bob

 

Hi Bob,

The shocks (Koni Adjustable) and the mounting brackets came as complete set. Look to be in very good condition, no rust scabs etc. Nice shiny original paint. Resistance seemed the same for both shocks. Rubbers in very good condition. No oil leaks and no other work carried out. The shocks were adjusted one full turn to each shock before fitting. I have to say that having 'bounced' the rear of the car each side after fitting, that the nearside did seam slightly softer. I haven't checked tyre pressures. Braking (no servo) as normal as usual, eventually stopping in a straight line. May be something not to do with the kit but just seams coinsidental.

 

Cheers,

 

Kev.w

Edited September 14, 2008 by kev.w

[robgeev]

Check trailing arm bushes, maybe compessing/decompressing as load changes?

 

Rob.

[TR 2100]

I have noticed today, that when changing up from 3rd to 4th gear, on occation my TR4A

veers quite sharply (under acceleration between gears) to the left.

Difficult to come up with a logical suggestion on the information given.

 

You say "on occasions" - how frequently?

Does it ever happen when changing from 2nd to 3rd?

Does the veering left happen more, or less, if you change gear at high revs

as against low revs?

Do you get any veering left when you brake?

 

AlanR

[kev.w]

Difficult to come up with a logical suggestion on the information given.

 

You say "on occasions" - how frequently?

Does it ever happen when changing from 2nd to 3rd?

Does the veering left happen more, or less, if you change gear at high revs

as against low revs?

Do you get any veering left when you brake?

 

AlanR

 

Hi Alan,

 

No veering to the left when braking. Only happened when accelerating after leaving roundabout onto dual carriageway, 2nd to 3rd ok then clutch down to change to 4th and veered to left. I have checked the rubber bushes on the rear trailing arms and they do look perished and cracked. Could be a combination of worn bushes, harder suspension at rear compared to front and maybe the camber of the road. Only happened a couple of times. The first time, coming off the roundabout was quite scary. I slowed my driving down after that, just to be careful.

 

Thanks,

 

Kev.w

[Rhodri]

Are you getting the IRS "twitch" where the splines lock in the drive shaft as the drive is on and under load? As you push the clutch down, to change gear, the pressure comes off the splines, the axle suddenly lengthens/shortens and unseats the back end of the car. My TR4 is a live axle, but I believe that the IRS twitch is well documented.

[kev.w]

Are you getting the IRS "twitch" where the splines lock in the drive shaft as the drive is on and under load? As you push the clutch down, to change gear, the pressure comes off the splines, the axle suddenly lengthens/shortens and unseats the back end of the car. My TR4 is a live axle, but I believe that the IRS twitch is well documented.

 

Rhodri,

 

I think you could be right. Just read an article about improving rear suspension/handling by Roger Williams and 'the twitch' is mentioned. I've only owned the car for about 6 months and still getting to know it. Winter will be a busy time for me, sorting out the ride quality and general re-newing of all rubber bushes, etc. Any ideas welcome !!

 

Thanks again,

 

Kev.w

[bob-menhennett]

Kev

 

Best of luck with the rebushing...the process of gradual elimination works eventually.

 

Bob

[kev.w]

Kev

 

Best of luck with the rebushing...the process of gradual elimination works eventually.

 

Bob

 

Thanks Bob.

[piman]

Hello Kev,

 

it is almost certainly drive shaft lock up. The first thing to do is to disconnect the drive shaft flanges form the differential, split the drive shafts, i.e slip the inboard section off the splines of the outboard section, then liberally apply molyslip grease to the splines and reassemble.

 

If that doesn't cure it then replacement shaft(s) are needed or just get used to it, as it feels worse than it is.

 

Alec

[Badfrog]

Hi Kev,

 

I don't want to play the obnoxious frenchman, but seems to me, post after post, that it is a nasty beast you're working on.

I could tell, I've got a similar case at home. Don't expect a miracle: I beheaded mine just to get even. BWAA* is the name of the game (*B...h With An Attitude).

 

I personnally experienced "madness at the roundabout" with my live axle TR4. It was due to a higher setting of the rear of the car due to 16" rims (anything goes for higher speed). After trying almost everything, I put back the original wheels with 165.15 tyres. This lowered the rear by 0.5" (heights taken at mid wheel arch) under the level of the front (as it should be) ... and the car stopped veering.

In your case, a set of shocks a bit too long might jack up the rear just enough. Of course, that might come on top of spline lock.

 

Er...Holmes-wise, did the car howled in the veering?

 

Regards,

Edited September 15, 2008 by Badfrog

[Ragtag]

I think you could be right. Just read an article about improving rear suspension/handling by Roger Williams and 'the twitch' is mentioned. I've only owned the car for about 6 months and still getting to know it. Winter will be a busy time for me, sorting out the ride quality and general re-newing of all rubber bushes, etc. Any ideas welcome !!

 

Hi Kev,

 

Having viewed you excellent mount on a few occasions, I find it hard to believe that anything could be worn out or need replacing. Don't let the Wessex group know or you might have to give the Cup back.

 

On the subject of the Konis, it may well be that they are just too harsh, even on the lowest setting. I had this with a Capri, years ago and it felt like I had no springs. You can certainly get non adjustable gas shocks and I'm sure there will be someone on the forum who can recommend something suitable.

[kev.w]

Hi Kev,

 

Having viewed you excellent mount on a few occasions, I find it hard to believe that anything could be worn out or need replacing. Don't let the Wessex group know or you might have to give the Cup back.

 

On the subject of the Konis, it may well be that they are just too harsh, even on the lowest setting. I had this with a Capri, years ago and it felt like I had no springs. You can certainly get non adjustable gas shocks and I'm sure there will be someone on the forum who can recommend something suitable.

 

Hi Chris,

 

I must admit, as mentioned at the start of this topic, that the suspension is now too hard. Over the weekend I'm going to adjust the Koni's to their softest setting and see if there is much difference. If not, then I will talk to Colin at CTM. I will also grease the splines as has also been suggested. Dont want to spend too much time under her though as the weather looks as if it could be good. Hows the '6' ? Have you fitted those springs yet ?

 

Cheers,

Kev.

[Ragtag]

Hi Chris,

 

I must admit, as mentioned at the start of this topic, that the suspension is now too hard. Over the weekend I'm going to adjust the Koni's to their softest setting and see if there is much difference. If not, then I will talk to Colin at CTM. I will also grease the splines as has also been suggested. Dont want to spend too much time under her though as the weather looks as if it could be good. Hows the '6' ? Have you fitted those springs yet ?

 

Cheers,

Kev.

 

Ahh yes.....the 6. Actually it was running fine up to the point where I "threw in the towel", quite literally and put her in the garage to dry out. I have taken the seats and carpets out and I keep checking for signs of death watch tin worm but so far so good. The springs were bought to give me something to do over the winter so no, not fitted yet. My intention is to work my way round each corner and overhall the complete suspension. I have ordered CTM brackets for my telescopic conversion which was why I was interested in your handling woes. I'm sure Colin will be able to advise, if no opinions are forthcoming from the forum but in any event, I know the TR Shop do a gas shock of Japanese origin but I don't know the price and "harshness" yet.

 

BTW, when is this good weather coming?

[littlejim]

That sort of behaviour was evident on my 4A when the rear wheel setup had positive camber on the rear wheels. Anything that made the back squat, heavy foot, sharp corner, produced some interesting behaviour as the wheel under load changed from positive to negative and back again in a few milliseconds.

When I got the rear camber to zero life was a lot more pleasant.

In my case I found that the PO had forked out his hard earned dollars to pay someone to fit the wrong springs.

[Badfrog]

Kev,

 

In contrast to many TR drivers overhere, I've always favored Spax shocks over Konis both for my TR4 and my Volvo 122S, as they are adjustable with a simple screwdriver without dismantling. And they last a lot longer too.

 

The fact that your Konis are too hard concurs to the ride height level problem I mentionned earlier as they will act against normal lowering of the rear during car position changes relative to the road (hope this is clear). An incorrect setting of the rear will perturbate mass transfer, hence veering. It will also be detrimental when braking or downshifting, for the same reason.

Whatever kind of axle you have might give different ideal figures for rear ride height and shock stiffness but the basic rule remains the same: If the rear is too high or too hard, you'll get poor handling.

 

BTW, has anybody in the forum ever tried 16" rims like some guys used to mount on TRs in the 50's-60's rallyes?

I realized that it was a mistake to have them at the rear only but I'm considering trying a full set. Even if I could not take a roundabout at 25 mph, I managed a solid 122 mph on a straight bit of motorway (consider the wheel development increase with 175.80.16 tyres over 165.80.15 tyres).

 

Regards,

Edited September 17, 2008 by Badfrog

[67_gt6]

I have Konis front and rear, set to about half, with no problems. This is using CTM brackets on the rear. Which conversion do you have Kev? I see you got them s/h , were they definitely supplied to the previous owner as a kit or is there a chance that you have the wrong dampers for the application?

 

I was under the impression the Koni Classics only offer rebound damping in which case they should not affect ride height or changes in camber, but I may be wrong.

 

I experienced intermittent twitch before I replaced my driveshafts with the tyoe with Teflon coated splines.

 

Andy

[88V8]

Bowtie has 16" rims on his 6. I forget the exact tyre size, but 205 something at the front, 215 at the rear. See his website.

 

Back to this topic.... what puzzles me, why only the twitch 3rd to 4th?

After all, there'd be far more torque reaction 2nd to 3rd and even more 1st to 2nd.

 

I think, if it were the suspension bushes it would be happening all the time. I suspect instead that there is some occasional interaction between the driveshaft splines and the harder shocks, perhaps when traversing a particular sequence of bumps at the greater speeds natural to the higher gears.

As it would cost nothing, I'd agree with those who suggest the first port of call would be to regrease the splines.

 

Still puzzled about 1st/2nd & 2nd/3rd though.

 

Ivor

Edited September 17, 2008 by 88V8

[Badfrog]

Bowtie has 16" rims on his 6. I forget the exact tyre size, but 205 something at the front, 215 at the rear. See his website.

 

Hi Ivor,

 

I checked on Bowtie's TR6 as you mentionned. What can I say? I would not do this to a Peugeot... Now really, I don't get it. Drive British steel or drive Detroit muscle (I've had both), but don't bastardize. There was only one Carroll Shelby ever.

 

Then again, it's a free world....

 

BTW, I got my new Spax tonight AND the new TS needles for the HS8 SU's. Can't wait for the w-e to get them on and go pushing 306's. ...

Edited September 18, 2008 by Badfrog