Trailing arm geometry S.O.S.
Discussion
Soo long story short my tasmin's chewed through the brand new rear tyres in less than a thousand miles, this struck me as a little suspicious so i took it to get the geometry checked at a local tyre depot. The front tracking was out by 3mm so that was remedied and they kept quiet about the rear saying that it wasn't adjustable and didn't really talk about it further which I didn't like. Checked at work with our own geometry checker, the rear's on -2.5deg on the rear right and -2.0deg on the rear left, as opposed to the -1deg i've seen recommended for most wedges. That's not even the alarming part though, checked the toe on the front, bang on where it should be, 3mm toe in, so at least the tyre depot did that part right. Checked the rear however, 12mm toe OUT, as opposed to the recommended 2mm toe in.
So yeah problem found but how does one remedy this on a trailing arm wedge? would be nice to fix both but i think the toe is the priority here and to make that sort of adjustment i think it'll require more than just a few shims no?
Any help greatly appreciated.
So yeah problem found but how does one remedy this on a trailing arm wedge? would be nice to fix both but i think the toe is the priority here and to make that sort of adjustment i think it'll require more than just a few shims no?
Any help greatly appreciated.
At the front of each arm where the big rubber bung is, there are a bunch of washers between the arm and the bung.
To toe in more, remove washers, and vice versa.
If you are lucky the washers are slotted for relatively easy removal without undoing the entire arm.
Once you have it set, slacken off the nut again, get the car weight on the rear wheels (jack under the hub) and then torque up the nut, so the rubber is not under torsion on the level.
To toe in more, remove washers, and vice versa.
If you are lucky the washers are slotted for relatively easy removal without undoing the entire arm.
Once you have it set, slacken off the nut again, get the car weight on the rear wheels (jack under the hub) and then torque up the nut, so the rubber is not under torsion on the level.
Many thanks, will get the back jacked up and check for washers etc. The previous owner had poly bushes fitted all round so i suppose it's possible he forgot to reinstall them maybe? don't recall seeing any stacks of washers the times i've been under the car. Also I don't suppose you know roughly how many washers equate to how many degrees or is it trial and error all the way?
As far as i'm aware the previous owner had a garage fit all the parts so it could just be whatever the garage had laying around as a makeshift spacer? will continue to do some digging around and see what crops up. are the parts required for building up these bushes still readily available today? stepped bolt for the centre and whatnot?
Yeah the photo Zig posted up is the original part, however these are expensive, hard to get maybe, and don't last too well (ok for 30k miles but start to wear out nearer 60k).
Looking at your setup I would take out that spacer and grind it down to maybe half its current width, put it back in and add washers as well. Then you will have some adjustability.
I have a trailing arm in my barn and could make some more accurate length measurements so you can get it right first time, given your starting measurements.
With the bolt you have it may be that the trailing arm has been drilled for the bolt so you might have to stick with that setup as the original pin (which also isn't very strong) might be too thin for the 'ole.
Looking at your setup I would take out that spacer and grind it down to maybe half its current width, put it back in and add washers as well. Then you will have some adjustability.
I have a trailing arm in my barn and could make some more accurate length measurements so you can get it right first time, given your starting measurements.
With the bolt you have it may be that the trailing arm has been drilled for the bolt so you might have to stick with that setup as the original pin (which also isn't very strong) might be too thin for the 'ole.
I can see where you're coming from with the spacer not looking right zig but what seems odd about the bolt itself? Matches pictures I've found online pretty well I think.
Will try and get it off tonight and as you suggested grind it down to replace with some washers.
In an extreme case, assuming I can't get enough adjustment with removing shims, could I start shimming the bushing back from the bracket it mounts to to achieve the same effect or is that asking for trouble?
Will try and get it off tonight and as you suggested grind it down to replace with some washers.
In an extreme case, assuming I can't get enough adjustment with removing shims, could I start shimming the bushing back from the bracket it mounts to to achieve the same effect or is that asking for trouble?
mrzigazaga said:
Actually it could be the correct part...I cant remember who makes the red bushes...flowflex...I was advised to keep away from the red and orange type...Here is what the original looked like..
The bolt definitely looks wrong....
RT.....but not cheap.The bolt definitely looks wrong....
Transformed my cars handling replacing those !!
Must say the back end does feel a little loose around corners which I guess would be the toe out as the weight transfers to the outside? World be nice to have it a bit more stable.
Any reason not to have the trailing arm butted right up against the bushing sleeve without any spacers or washers? Do all the adjustment in one place between the bushing and the bracket on the chassis sort of thing?
Any reason not to have the trailing arm butted right up against the bushing sleeve without any spacers or washers? Do all the adjustment in one place between the bushing and the bracket on the chassis sort of thing?
Any obvious problems with this sort of solution then? get rid of the top hat looking spacer currently on it, add either a few thin or one thick shim between the bush and the bracket to move it back a bit, and have easily removable shims on the part of the bolt that goes through the trailing arm itself? could easily knock all of these parts up after hours at work so this solution is sounding very promising!
Edit:
above in the picture is current setup, lower in the picture is what i'm thinking should be a pretty good fix.
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