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Posted by: Alapone Jul 22 2015, 02:54 PM

I am having trouble getting my car aligned properly. The tech was saying the rear left was set to +1.00 camber. This was noticeable when crouching behind the car. The front alignment was substantially toe-in in order to counteract this.

Rewind 18 months: The car was slid into a curb which resulted in a bent wheel and some damage to the inside trailing arm hook up point (don't have the real term for this but I mean the ear where the inside bolt of the trailing arm hooks to the car. This was all supposed to have been fixed and straight.

Last week: Having recently finished a 5 lug conversion which retained the same rear trailing arms I went to go have an alignment done when they told me someone non specifically "something in the rear is bent".

How do I go about checking to see what is wrong? I assume autocross guys have good experience with this type of thing. Do trailing arms bend? Is the ear/hook up point the place to start? I'm sure I can find a used straight trailing arm for $100 or so here on the world but what am I up against if it is damage to the ear/hook up?

Any advice is appreciated

Posted by: SirAndy Jul 22 2015, 03:07 PM

Yes, they do bend and are designed to do just that
It's easier to replace a bent trailing arm than to fix a broken or ripped apart chassis.

I recall seeing a technical drawing many years ago that had all the trailing arm measurements and i even recall a jig made to check trailing arms for straightness.

Posted by: RobW Jul 22 2015, 03:31 PM

Andy is correct. The trailing arm on Dads car is bent from a lousy flat tow.

Posted by: bdstone914 Jul 22 2015, 09:52 PM

Probably a bent arm. Early 70-72 have a different flex brake line bracket than the 73-76. I have them and would sell one for $50 plus shipping. Bare arm no spindle bearing or hub.
Can sell one but you may find one closer to save shipping. they weight about 25 pounds.
Did you replace the bushings when you did the 5 lug? I suppose that distorted bushing could cause too much negative camber.

Posted by: mgp4591 Jul 22 2015, 10:20 PM

Small hijack here- so does the fact that they're meant to do that (bend vs. more damage) mean that it's not a good idea to reinforce them even if you're running lots more power and weight?

Posted by: SirAndy Jul 23 2015, 01:33 AM

Neither power nor weight are really the issue, especially not for a street car.

Reinforced trailing arms make sense for a track car running large sticky slicks ...

Posted by: Alapone Jul 23 2015, 05:57 AM

thanks guys. bdstone, yes we did replace bushings at the time of the conversion because they had worn unevenly. The right rear was completely worn out while the right left (where I have the issue) was not as bad.

This leads me to believe the problem with this car may have existed before I owned, or before the incident sliding it into the curb. Though the curb shot I gave it and this issue with the camber are too coincidental to not be related I think. How do I go about measuring the trailing arm to see if it is good? Are all trailing arms the same 70-76?

To be clear the tech at the alignment shop told me I have significant (1.00) positive camber on the rear left. (Top of the wheel is farther outboard than the bottom)

Posted by: rgalla9146 Jul 23 2015, 06:18 AM

Hey Andrew
We can remove your trailing arm and measure it against others I have.
It should be possible even without a jig.
This will determine where the issue is.
Rory
PS yes, new bushings installed

Posted by: Alapone Jul 23 2015, 07:03 AM

haha sry I didn't want to bother you on vacation! talk soon

Posted by: Dave_Darling Jul 23 2015, 04:32 PM

The Haynes manual has a photo of measuring the trailing arm and a spec for measurement. As with most of their photos (and words!) it came straight out of the factory manual.

--DD

Posted by: Racer Chris Jul 23 2015, 04:54 PM

There is a 1.5 degree negative camber built into the trailing arms.
That means if you have the pivot shaft perfectly level and the axle at the exact same height as the pivot shaft, the hub will have a negative camber of 1.5 degrees.
Any other results means the trailing arm is bent.

Posted by: rgalla9146 Jul 24 2015, 05:30 AM

great information, better than just a comparison
thanks Chris

Posted by: Alapone Jul 24 2015, 07:44 AM

thanks guys