Axle skew

[totta Crolla]

and steering left.
After fitting new and uprated rear link arm bushes my car seems to constantly want to steer left, I think it may be rear steer caused by axle skew. A front end alignment has been done.
When I re-fitted the axle after fitting the bushes it was very difficult to get the brakets to align with the link bars, I had to use a ratchet strap to pull the axle into position by about 8mm. Is this normal ?

[irishtwincam]

Fit bushes to arms.
Fit arms to body (no axle yet.)
Before tightening the nuts, push arms up as high as you can.
Now tighten the nuts.

Hang axle from arms and tighten bolts to hold on axle.
Now rear arms are "bound".

This is what I have done using Prothane from T3.
Aligned as follows.


No problems.

[totta Crolla]

Do you think an off centre axle could cause my problem ?

[irishtwincam]

Is your car lowered?
If yes, you MUST fit an adjustable panhard rod.

[totta Crolla]

irishtwincam Wrote:Is your car lowered?
If yes, you MUST fit an adjustable panhard rod.

Thanks, got one on its way

[jondee86]

Seems you could have more than one problem. Factory procedure for
mounting rubber bushins to the back links, is to fit all the links without
tightening any of the bolts. Then you set the car on the floor and bounce
it a couple of times to make sure it is at normal ride height.

Then jack the car up under the diff just high enough to get under
and torque the bolts up. This makes sure that you don't get the rubber
acting as a spring, and affecting the ride height. TRD rubber bushes are
firm enough to change the ride height by an inch or more, if you tighten
them with the axle hanging down (jacked under the frame rails).

If you had to pull the axle into position, something must be bent.
Usually, just poking a screwdriver in the hole and giving it a nudge
would be all it takes to get the bolts into the holes.

Cheers... jondee86

[jondee86]

Adjustable panhard rod is nice, but the tiny amount of misalignment
you get from lowering the car is not enough to affect the handling
Some will argue it, but for years I had a lowered AE86 with the factory
panhard rod, and it drove straight and true.

Biggest benefit of the adjustable rod, is to allow you to dial out a bit of
guard rub, if it only happens on one side.

Cheers... jondee86

[jondee86]

But if you can't find anything bent, here is one last thing I discovered,
and it helped me to improve the handling of my car when it was pulling
to one side. Align the steering.

Get underneath and measure the how much of the thread is showing
on the tie rod end adjustment, both sides of the car. Just in case you
have two different tie rod ends, measure from some reference point
under the ball joint, back to some reference point on the rack end (inner
ball joint).

These measurements should be the same.

If they are not, loosen the lock nuts and wind the long side in by a certain
number of turns. and the short side out by the same number of turns. Do
this until both sides are the same.

Then you might need to get inside the car and shift the steering wheel
around a couple of splines, so that it lines up with the new straight ahead
position. Good luck

Cheers... jondee86

[totta Crolla]

Yes Jondee it's interesting you mention the Panhard Rod and lowering, when I removed mine I drew the arc that it took on the floor and at no point over a sixty degree radius did it change by more than 10mm. Of course that could be 20mm difference side to side if lowering the car makes the rod completely parallel to the axle.
I want to get the axle dead centre so that I can adjust the toe angle using the back wheels as a reference.
You also mention rack centreing and I think it is extremely important on an AE86 just a few millimetres out and I found you can start to introduce bad bumpsteer.
To find the rack centre I removed the rubber bellows each end of the rack and measured the protrusion of the actual rack from the housing to the point where it joins the track rod, on my car this is 83.75mm each side. I don't have facilities to lock the steering at this point but I stuck some masking tape on the steering wheel, marked it with a line and made a pointer from the dash to look at it. I then had the alignment done.

[jondee86]

totta Crolla Wrote:Yes Jondee it's interesting you mention the Panhard Rod and lowering, when I removed mine I drew the arc that it took on the floor and at no point over a sixty degree radius did it change by more than 10mm. Of course that could be 20mm difference side to side if lowering the car makes the rod completely parallel to the axle.

I just made a diagram and calculated the sideways movement of the
rear axle due to lowering the car by 40 mm. From memory, it was
something like 1.75 mm. This is all you have to compensate for with
the adjustable panhard rod. I put a bend in the factory item, near one
end, enough to shorten it by 1.75 mm. My bar finished up looking like
the Whiteline one. Total cost... nada !!!



Works for me

Cheers... jondee86