SteveWallace
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| posted on 11/6/13 at 12:39 PM |
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Rear wheel toe in/toe out
I've been setting up the tracking etc on the Viento today and have done the rear camber and front camber/caster/toe in. Whilst I had the kit to
hand (home made, based on a laser pointer) I decided to check the alignment of the rear wheels.
Unfortunately, they have 0.8mm of toe out and I estimate my measurment accuracy to be about +/- 0.1mm. I know that rear wheel toe out is not good,
but is this much something that I can live with or do I need to do something about it?
There is no continuous adjustment for toe in/out for the rear wheels so the only way that I can see to do it is to shim two bolts out of the four that
hold the hub to the hub carrier on each side. Given the spacing of the bolts compared to the diameter of my wheels, the shims would need to be very
thin.
Also, doing this would obviously mean that the mating faces of the hubs and hub carriers would not be flat against each other (probably only by a
fraction of a mm) - would this create unacceptable stresses?
Views and advice would be appreciated.
Forgot to say, if I am going to bother doing this, should I set them dead straight or go for a bit of toe in (and if so, how much)?
[Edited on 11/6/13 by SteveWallace]
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procomp
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| posted on 11/6/13 at 01:01 PM |
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Hi
1-3mm toe in, but more important than the overall toe in figure is getting the thrust alighnment correct at the front axle. ;-)
Cheers Matt
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Slimy38
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| posted on 11/6/13 at 01:28 PM |
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quote:
Originally posted by SteveWallace
Also, doing this would obviously mean that the mating faces of the hubs and hub carriers would not be flat against each other (probably only by a
fraction of a mm) - would this create unacceptable stresses?
If you do go down this route, you'll be following in the footsteps of others who have had no problem. It's a common fix for VW Audi cars
with a fixed beam rear axle, using shims behind the hub to correct toe.
Take a look at this as an example;
Rear Alignment Shims VW Polo 6N | eBay
Rude Racing Car Accessories - Rear Alignment Shims VW Polo 6N
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SteveWallace
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| posted on 11/6/13 at 01:28 PM |
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By 'getting the thrust alignment right' do you mean making sure that the rear wheels are straight - i.e symetrically point forward with an
equal degree of toe in?
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nick205
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| posted on 11/6/13 at 03:06 PM |
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I shimmed the rear hubs on my Indy toe equalise and centre line the rear toe. As built with no adjustment, one wheel was toed out significantly, the
other a little. It's a relatively easy and very cheap mod and gave noticeable improvements in handling. I got shim washers from Namrick in a
range of thicknesses for very little money.
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loggyboy
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| posted on 11/6/13 at 03:13 PM |
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quote:
Originally posted by SteveWallace
By 'getting the thrust alignment right' do you mean making sure that the rear wheels are straight - i.e symetrically point forward with an
equal degree of toe in?
Yep.
[Edited on 11-6-13 by loggyboy]
Mistral Motorsport
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Bluemoon
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| posted on 11/6/13 at 03:20 PM |
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This might come in handy:
http://www.merkurtech.com/merkurtech/techarticles/item010.php
Dan
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SteveWallace
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| posted on 11/6/13 at 03:37 PM |
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Having measured how far the hub carrier bolts are away from the centre line of the drive shafts, I calculate that 0.2mm shims on each side will change
the set up from 0.8mm toe out to 1mm toe in on each side.
Given these small changes, I think that I may get away with using shim washers rather than having a whole shim plate machined to fit. First job is to
rotate the wheels through 180 degrees and remeasure just to make sure that they and the discs are seated properly and not causing the problem.
With these small errors, I'm amazed that the wishbones, hub carrier and chassis were made to such close tolerances in the first place
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renetom
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| posted on 11/6/13 at 04:23 PM |
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Hi
On our Indy we had one side towing in & one out, Which gave us
rear steering , made up some shim washers out of some 1/2mm stainless.
job done,
Good luck.
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rusty nuts
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| posted on 11/6/13 at 07:07 PM |
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Ask at your local engineering supplies company for shim stock, I used to have a small tin with various thickness steel about 4 inches width which I
think would be ideal for this job, easy to cut with scissors and use a wadding punch for holes
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