D1 Left Front Tyre Abnormal Wear

[gazk]

I have a problem that has developed in the last month or so with the left front tyre on my 93 TDI wearing abnormally on the outside edge. The right side is fine. Have run Pirelli Scorpion ST's on it since new and the wear has always been more or less equal on both sides. Using bilstein gas shocks all round and there is no scalloping on tyre edges.

I rotate the tyres back to front around every 5000k. Tyre pressures are equal (about 30psi). Each time it has a wheel alignment (tried a couple of places with same result) it ends up pulling to the left and needs to be tweaked to get it to run straight. This happens with both new and worn tyres.


Suspect something has gone wrong in the left front steering or suspension. Any ideas?

Thanks Gary

[one_iota]

Had this happen to me and it turned out that the steering tie rod was bent (the rod that connects the wheels together at the rear). It caused the front left wheel to point out. When I applied the brakes the car pulled to the left and eventually the inside left of the tyre wore.

I blame some rough work off road and now use a heavy duty tie rod :cool:

[cucinadio]

Had this happen to me and it turned out that the steering tie rod was bent (the rod that connects the wheels together at the rear). It caused the front left wheel to point out. When I applied the brakes the car pulled to the left and eventually the inside left of the tyre wore.

I blame some rough work off road and now use a heavy duty tie rod :cool:


mmm very interesting even i got somthing out of the one !!! :eek:

grazi

[Ken]

I have a problem that has developed in the last month or so with the left front tyre on my 93 TDI wearing abnormally on the outside edge. The right side is fine. Have run Pirelli Scorpion ST's on it since new and the wear has always been more or less equal on both sides. Using bilstein gas shocks all round and there is no scalloping on tyre edges.

I rotate the tyres back to front around every 5000k. Tyre pressures are equal (about 30psi). Each time it has a wheel alignment (tried a couple of places with same result) it ends up pulling to the left and needs to be tweaked to get it to run straight. This happens with both new and worn tyres.


Suspect something has gone wrong in the left front steering or suspension. Any ideas?

Thanks Gary

Are you running an after market steering damper (Coil over type)?

It depends on who you go to for your wheel alignment also
most will set the thing at factory spec which isnt allways right in the first place
I would say 1degree of toe in total for a D1 would be about right any more and you start to wear the inner edge of the front tyres
Castor will also have a part in the pull to the left
do you have a read out of your wheel alignment ?

[Graeme]

Checkout the bushes in the radius rods, especially the left one.

[gazk]

Had this happen to me and it turned out that the steering tie rod was bent (the rod that connects the wheels together at the rear). It caused the front left wheel to point out. When I applied the brakes the car pulled to the left and eventually the inside left of the tyre wore.

I blame some rough work off road and now use a heavy duty tie rod :cool:
Thanks for the information, I've checked the tie rod and it looks straight. It hasn't been off road recently and there is no obvious damage, its only done about 4000Km since last align but will be having it checked again.

Gary

[gazk]

Are you running an after market steering damper (Coil over type)?

It depends on who you go to for your wheel alignment also
most will set the thing at factory spec which isnt allways right in the first place
I would say 1degree of toe in total for a D1 would be about right any more and you start to wear the inner edge of the front tyres
Castor will also have a part in the pull to the left
do you have a read out of your wheel alignment ?

Thanks Ken, It has done 223000Km (I've driven 200000km of that) and has the original steering damper, never had any issue with that. The inner edges of the tyres are OK although generally it has always worn the edges out first. I run the tyre pressures slightly higher than the recommended 28psi on the front. I have a readout of the alignment before last stowed away up in Sydney, from memory everything was within limits then, will check that next weekend.

Gary

[justinc]

Gaz,
I've seen thes D1's with shorter wheel base on the left than the right before, up to 18mm!!!
(One would think the alignment equipment would pick this up though)
This can cause crabbing down the road and wear front tyres enevenly like you describe. Run a tape measure between the axle centres on both sides and see if it is close..I bet it isn't.

We had to space them behind the trailing arm bush to rectify this.

BTW, most wheel alignment places are incorrectly toeing these IN. They should have 0 to 2 mm Toe OUT.

JC

[gazk]

Checkout the bushes in the radius rods, especially the left one.
Thanks Graeme, I was thinking along those lines as all the bushes are original. I might just order the parts before I start pulling it apart. (I'm in Nowra and parts are not necessarily available at short notice.)
Would the panhard rod bushes also make a difference?

[gazk]

Gaz,
I've seen thes D1's with shorter wheel base on the left than the right before, up to 18mm!!!
(One would think the alignment equipment would pick this up though)
This can cause crabbing down the road and wear front tyres enevenly like you describe. Run a tape measure between the axle centres on both sides and see if it is close..I bet it isn't.

We had to space them behind the trailing arm bush to rectify this.

BTW, most wheel alignment places are incorrectly toeing these IN. They should have 0 to 2 mm Toe OUT.

JC
Thanks Justin, I noticed in my original LR 1993 revision workshop manual toe out between 0 and 2mm (0deg 0min to 0deg 16min ) is specified. I have the printout from a previous alignment stowed away but I'll drop in to the see the guys who did that alignment tomorrow and find out what figures they are working to. Problem might be a combination of some worn-out bushes and alignment settings.

Gary

[mcrover]

Id be looking at camber as well, some worn swivel bushes can change the camber quite considerabley but I would be putting money on the wheel base as Justin said, this is really common with Jeeps as well with similar results.

You also have to realise that most 2 lane roads have right to left camber built in which makes most cars with limited caster track left so you may be dialing in too much toe in when giving it the tweak that you posted earlier trying to combat the camber of your local roads.

If the toe adjustment is incorrect it normally will wear both front tyres edges rather than just 1 and the same with a bent drag link (tie rod) which will most likely also lead to the steering wheel being off centre and in extreme cases reduced turning circle one way or the other.

Worn steering damper or shocks will cause feathering and steering damper normally will give you a steering vibration like an unbalanced wheel at speed.

[Graeme]

Thanks Graeme, I was thinking along those lines as all the bushes are original. I might just order the parts before I start pulling it apart. (I'm in Nowra and parts are not necessarily available at short notice.)
Would the panhard rod bushes also make a difference?
The radius rod bushes can be checked using a big screwdriver to lever the arm about to get a good view of what's happening.
Worn panhard rod bushes will give wheel shimmy and wandering.

[gazk]

Id be looking at camber as well, some worn swivel bushes can change the camber quite considerabley but I would be putting money on the wheel base as Justin said, this is really common with Jeeps as well with similar results.

You also have to realise that most 2 lane roads have right to left camber built in which makes most cars with limited caster track left so you may be dialing in too much toe in when giving it the tweak that you posted earlier trying to combat the camber of your local roads.

If the toe adjustment is incorrect it normally will wear both front tyres edges rather than just 1 and the same with a bent drag link (tie rod) which will most likely also lead to the steering wheel being off centre and in extreme cases reduced turning circle one way or the other.

Worn steering damper or shocks will cause feathering and steering damper normally will give you a steering vibration like an unbalanced wheel at speed.
Thanks, the drift to the left happens happens on roads with little or no camber. There are no vibrations in the steering system. I've found the alignment data from just over 12 months ago and the final measurements showed individual toes at 0.0mm and total toe at 0.1mm. Even after that alignment it had a drift to the left on a flat road. As a Christmas present for the Disco I'm going to pick up a full set of front-end bushes on Friday, I'll let you all know the results in a couple of weeks.
Gary

[gazk]

Gaz,
I've seen thes D1's with shorter wheel base on the left than the right before, up to 18mm!!!
(One would think the alignment equipment would pick this up though)
This can cause crabbing down the road and wear front tyres enevenly like you describe. Run a tape measure between the axle centres on both sides and see if it is close..I bet it isn't.

We had to space them behind the trailing arm bush to rectify this.

BTW, most wheel alignment places are incorrectly toeing these IN. They should have 0 to 2 mm Toe OUT.

JC
Hi again Justin, I measured the wheelbase on each side, they are the same given the tape measure positioning accuracy. (about 2mm difference) There is some movement in the radius arm bushes with slightly more on the left, so I think I'll start there and check the steering damper while I'm at it. Any recommendations on steering damper replacement ?

[justinc]

Hi again Justin, I measured the wheelbase on each side, they are the same given the tape measure positioning accuracy. (about 2mm difference) There is some movement in the radius arm bushes with slightly more on the left, so I think I'll start there and check the steering damper while I'm at it. Any recommendations on steering damper replacement ?

QUICK, send you truck to the Dunsfold LR museum. It must be the only one within 5mm in existence!!:p:p

Seriously, that is a good thing. Yes, as mentioned by others I would toss the radius rod bushes if too much play, and use only genuine metalastic ones.

Steering dampers. I have a Bilstein one on mine, (previously a Koni one that I bent almost double:mad:(Why do RR's have their dampers in such STUPID places???))The bilstein one is fantastic. costs $$$ but worth it, even with my 33" mudders on steers fine.

JC

[mcrover]

My ridepro steering damper is a fair bit cheaper than a billy and seems to work fine and Im running 235 85 16's but the quality of the Billy will always be among the best.

[gazk]

QUICK, send you truck to the Dunsfold LR museum. It must be the only one within 5mm in existence!!:p:p

Seriously, that is a good thing. Yes, as mentioned by others I would toss the radius rod bushes if too much play, and use only genuine metalastic ones.

Steering dampers. I have a Bilstein one on mine, (previously a Koni one that I bent almost double:mad:(Why do RR's have their dampers in such STUPID places???))The bilstein one is fantastic. costs $$$ but worth it, even with my 33" mudders on steers fine.

JC
Hi again guys, put it back on the wheel alignment rig again yesterday for a quick check. The camber on the left has gone from being on the limit (-0.5degrees) in September 2006 to -1.25 degrees (Leaning out at the top) Time for a swivel housing overhaul and maybe a few other bits while I'm at it!

[gazk]

Just a follow-up to my tyre wear problem. Replaced the swivel pins and bearings on the left side (as well as the wheel bearings and all seals) and and it now drives straight with no odd tyre wear. I got interrupted by family needs over the New year and plan to do the other side soon as well as the radius arms. Interestingly I found an axle seal that had been put in backwards when I had the swivel housing seals replaced by a LR specialist back in 1995, expains why the diff oil level was always high and I needed to keep topping up the swivel pins (drained about 4 litres from the 2.7litre diff this time!)

I'm now a lot wiser about Disco front axles etc. Thanks for all the advice.