Tyre wear, tracking, rear axle....i'm stumped!!

[reb78]

Well - i'm trying to do both really. I want to set straight ahead properly and then once that is done, I want to do the tracking properly too. Its just in trying to do it, it has thrown up this problem.

[Early90]

Ignore what you have found with the rear for now. I had a bent axle/stub after a Ford Focus hit my offside rear wheel, it bent the rim and the only other visible damage was the rear trailing arm bush (poly) was pushed out the side. Even when the arms and bushes were replaced on both sides the problem was evident when driving because the rear end used to wag like a dog and I could steer with the throttle...you are not complaining of handling problems so don`t worry about the rear until you have sorted the front.

I would start again, steering wheel off, centre the box with the bolt again and track it using one of the methods above. Then drive it to ProTyre or elsewhere who have a four wheel alignment machine and get a check or get them to set the front. You will get a print out of all the positions of your wheels, mine showed toe out on the wheel that was hit and we used this to claim a new axle case from the insurers.

Also measures between hub centres so you get a full picture of what`s going on.

[reb78]

Laser pointers would never last in my workshop. And waaay over the top for what we want. If you use the 2 metre lengths of box secion, you have multiplied the accuracy by a factor 4 or so. I cant think of a more accurate way of doing this. This is even more so when you want to go toe in/or out; 1 mm toe in becomes 4 mm toe in, which is much more accurate to measure with a tape than the usual way.

Daan

Daan,

Can you jog my memory with the maths? Parallel is easy, but i need a reminder of my trigonometry to work out the toe in/out with the 2m sections...

[reb78]

...you are not complaining of handling problems so don`t worry about the rear until you have sorted the front.

Yep - thats the thing - it drives perfectly really, no arse end steering, no wandering, just this wear and gettign the setup correct.

[Daan]

Daan,

Can you jog my memory with the maths? Parallel is easy, but i need a reminder of my trigonometry to work out the toe in/out with the 2m sections...

If you go 16", length is 406 mm, on a 2 metre section you can go 4 x 406 = 1625.6 mm. Make 2 marks on both your box sections in front of the car, 1625mm apart. Adjust untill you measure 4mm difference, you now have 1mm toe on your wheels, if that makes sense.

I go parallel normally, as the tyres wear of straight.

Daan

[mmgemini]

Daan

Where did you get that setting please.

All my Defender books say 0 to 2mm TOE OUT......

[Daan]

Daan

Where did you get that setting please.

All my Defender books say 0 to 2mm TOE OUT......

I got that setting from experience. the parralel setting that is. I only used the 1mm setting to explain my method. I set the steering parrallel, as that worked and the tyres wear off straight. Toe out gave it a wandering beheviour (not keen on going straight). According to your figures, thats still in tolerances. I am not for a moment suggesting anyone to use this setup, just sharing my experience.

Daan

[V8 Freak]

I set mine up parallel / no toe out as well Daan.

I fund it gives even tyre wear and as you comment, no twitchy steering or wandering.

Neil

[Eightpot]

Just wondering if your replacement steering box may have been of a different type to the original?

Is it possible the centreline of the drop arm is a little different to the original, pushing the drag link over slightly? Was the drag link adjusted?

I would start from square one, centre the box, set drag link length, set tracking and see if anything changes.

[reb78]

Just wondering if your replacement steering box may have been of a different type to the original?

Is it possible the centreline of the drop arm is a little different to the original, pushing the drag link over slightly? Was the drag link adjusted?

I would start from square one, centre the box, set drag link length, set tracking and see if anything changes.

Yep - I went 6 bolt to 4 bolt. When I fitted it, I centred the box properly (minimal adjustment was required surprisingly).

[Eightpot]

Maybe try shortening the drag link a tad then and see if that reduces the pull to the left? I've had similar symptoms when using different boxes and a little adjustment sorted it. It's a quick one to try anyways.

[mmgemini]

Maybe try shortening the drag link a tad then and see if that reduces the pull to the left? I've had similar symptoms when using different boxes and a little adjustment sorted it. It's a quick one to try anyways.

AH ! ! somebody agrees with me at last.

Daan

I can only set the tracking as Land Rover suggest.to their limits. The last set of tyres I replaced after 40,000 miles had a depth of 4mm to 4.5mm all across the tread. Methinks that's about right.

Of course as a mechanic I know nothing I han't been doing tracking on vehicles very long. Only since 1958 No experience then ???

I would expect that if a left tyre was running off on the outside then it would come to two things. Tight right hand corners. Or wrong drag link setting

[reb78]

Daan is saying the same settings as you Mike. 0mm toe out is parallel. 1mm toe out at the wheel equates to a greater distance at the end of a straight edge 2meters in front of the wheel.

I'll take another look at the drag link, but in my head, if the drag link measurement is out it would still only wear the tyres if the tracking was wrong surely?

[Eightpot]

No, the steering box will self centre while you drive. If the drag link hasn't been set accurately and is a little too long it pushes the wheels across to the left, meaning the car is always steering left a bit - you are countering this by always steering to the right.

You probably only need twp or three turns on the track rod end to correct it.

[Aragorn]

Does the box itself actually self centre? Or does it self centre due to the caster forces coming from the wheels?

I wouldnt have thaught the box itself would try to centre the wheels, more the wheels will try to center the box...

[reb78]

With regard to its current position, the steering box is set so that a bolt will fit perfectly through the drop arm slot and bolt screw into the location hole in the box - so, i think that is centred properly. I guess that the drag link adjustment to set where the nearside front wheel sits in the straight ahead position is the difficult thing given the angle on the string presented by the nearside rear wheel.

[mmgemini]

I would think the box is centered correctly.

There is a definate drag link lenght. Ralf will produce it for you......The silly thing is. The Paynes Defender book doesn't mention the lenght. The Paynes Discovery book does. Also for the Discovery there's two drag link lengths. Early and late.....

Youre not getting understeer on a right hanmd bend somewhere on your journey ? You know where a bend tightens up and you apply more lock because you know the corner, without lifting off ?

[Aragorn]

Roundabouts are a common one for scrubbing the right hand front outer shoulder if you often proceed in a spirited manner!

Even with perfect geometry, you'll still scrub off the outer shoulder of the front right if you like "pressing on" at roundabouts

[Bowie69]

Roundabouts are a common one for scrubbing the right hand front outer shoulder if you often proceed in a spirited manner!

Left hand front outer surely...?

[western]

There is a definate drag link lenght. Ralf will produce it for you......The silly thing is. The Paynes Defender book doesn't mention the lenght. The Paynes Discovery book does. Also for the Discovery there's two drag link lengths. Early and late.....

Drag link nominal length is 924mm from ball joint pin centre to drop arm connection hole centre, see attached page

track rod nominal length ball joint pin centres 1230mm [figure is stated in Discovery 1 workshop manual, but not in defender manual, it's the same axle/track rod set up, so should be a decent starting point]

[Aragorn]

Left hand front outer surely...?

Yep, brain fart!

[mmgemini]

Reb

I know you said the one tyre but are they both scrubbing, the other not seeable ? Run the flat of your hand over the tyre tread from inside to outside then the other way. You can feel the feathering.

[landroversforever]

The steering box does not do the self centering, that is a product of the castor angle.

[Aragorn]

yeh this is what i thaught, the only affect i can see of a mal adjusted drag link, is an off centre steering wheel, and if you adjust the wheel to fix it, then you just end up with slightly less turns in one direction than the other.

[landroversforever]

yeh this is what i thaught, the only affect i can see of a mal adjusted drag link, is an off centre steering wheel, and if you adjust the wheel to fix it, then you just end up with slightly less turns in one direction than the other.

I agree, I can only see the wrongly adjusted drag link changing the steering wheel postition. The track rod is the only bit which sets how the wheels are in relation to each other and how the tyres wear (which is down to their relationship to each other). For example, you can still have LR's toe specs even if you for some reason had a drag link which needed full lock on the steering wheel one way to maintain straight ahead! Obviously that's just to illustrate a point

Set the tracking how you want it, either LRs toe in/out spec or parallel as several people (myself included) have theirs. and Then sort the drag link.