Rear toe in issues, -bent control arm? Options

[falcor75]

So I've just finished my car after a 4 year restoration. I got it roadlegal about a week ago and then went for an alignment. Everything was ok except the left rear wheel had 6 mm toe out and I was still at the max forward on the mount.

Went home again and started investigating. I measured the distance from the outer rear hole to the center of the pressed dimple in the middle of the floor. Distances are ok on both sides, about 846 mm

I elongated the holes in the outer control arm bracket about 5 mm and went back to the aligners. Better this time but still 2,4 mm toe out. Went home once again and filed up the holes even more. Now I could probably get to zero toe with the max adjustment but the amount of difference between the two sides are just....comical....

The only other thing I could think about is the left trailing arm being bent. So today I took both trailing arms out to compare them side by side.

(IMG:http://www.914world.com/bbs2/uploads_offsite/matsgarage.com-15176-1493574803.1.jpg)

Both control arms out, I joined them at the shock absorber mount with a piece of 18 mm diameter tube and places my long spirit level along the pivot arms.

(IMG:http://www.914world.com/bbs2/uploads_offsite/matsgarage.com-15176-1493574804.2.jpg)

As you can see there is a slight difference between the angle of the pivot axels.

(IMG:http://www.914world.com/bbs2/uploads_offsite/matsgarage.com-15176-1493574805.3.jpg)

The right side pivot axle follows the spirit level pretty closely.

(IMG:http://www.914world.com/bbs2/uploads_offsite/matsgarage.com-15176-1493574806.4.jpg)

The left one shows a little more deviation.....

I know this isnt the hole truth since I'm not measuring between the hub face and the pivot axis but its the best I can do at home.

What does the wisdom of the world say?

[falcor75]

Dammit, meant to post this in the garage, please move it if needed.

[ChrisFoley]

Not accurate enough to use the shock absorber hole for alignment.
For another data point, measure distance from stub axle center hole to center of pivot shaft at outboard end.

[McMark]

Either the trailing arm is bent, or the body. It's probably the trailing arm.

[914_teener]

I.ve seen this before as well when I did mine few years back.

The arms are fixtured at a compound angle when they are manufactured.

This needs to be checked prior to redoing the arms.

I vote for a bent arm as well.

[falcor75]

Not accurate enough to use the shock absorber hole for alignment.
For another data point, measure distance from stub axle center hole to center of pivot shaft at outboard end.

Right hand side (OK side) measures 400 mm from the inside of the M14 thread to the center of the hub splined hole.

Left side measures around 405 mm the same way.

Will try to get a friend over to get an indipendant measurment taken but it seems we've found the culprit. (IMG:style_emoticons/default/smash.gif)

[EdwardBlume]

I have a worse rear toe in problem on Dad's car currently.... McMark refurbished a set and added a tow loop a few years back.

The best I can tell is that when the car it came off of (rear part of the Limo) was towed after it was smashed, the car was either pulled or secured or both on the front part of the trailing arm itself bending it. I have 2 more sets but its really hard to tell if a trailing arm is tweaked until you mount it with a tire.

Dad's car isn't off because the original stock arms that came off were fine. I would have it fixed but I don't have a press for the bushing.

FWIW, on my old AX car, I had a tow loop on the back of the trailing arm and it worked really well. The tweak is more likely towards the front.

Good luck!

[McMark]

Rob, I have a known bent set of trailing arms here and I'll be building a checking fixture in the next week or two from a couple good trailing arms. The bent trailing arms are to make sure bad ones are identified by the fixture.

Once I've made it and confirmed it works, I'll get you set up with a straight pair, with tow loops, loaded with bearings and hubs.

[EdwardBlume]

Rob, I have a known bent set of trailing arms here and I'll be building a checking fixture in the next week or two from a couple good trailing arms. The bent trailing arms are to make sure bad ones are identified by the fixture.

Once I've made it and confirmed it works, I'll get you set up with a straight pair, with tow loops, loaded with bearings and hubs.

Thanks Mark. No one could have seen a bent pair, which is what makes it tough. I agree, a fixture is 100% the way to go. I have 2 extra sets of trailing arms here including the original stock ones from Dad's car if you need a set.

I bet tweaked ones come from towing / pulling the car with a wheel down.

[6freak]

I elongated the holes in the outer control arm bracket about 5 mm

bummer! theres some around
(IMG:style_emoticons/default/smile.gif) good luck

[falcor75]

Just to update the thread a bit. Replaced the rear left trailing arm and Went back for an alignment yesterday. Had put as much toe in on it as I could on the left rear and had 4 mm toe at the first measurement. We adjusted to 1 mm toe in on all four corners. DONE ! (IMG:style_emoticons/default/smile.gif)