Shocking discovery inside trailing arm
Thread Starter
Pro
Joined: Aug 2010
Posts: 651
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From: Napa, CA
Shocking discovery inside trailing arm
I recently decided to rebuild the rear suspension on my 73 4sp coupe. What caused me to make the leap was a sudden loud clicking noise emitting from the driver side rear bearing and an apparent missing c-clip on the driver side side yoke causing the yoke to pull out of the differential when the suspension was unloaded. The guy who rebuilt my arms said that the driver side unit was missing some essential components when he disassembled it, namely, there was no spacer or shim! He rebuilds trailing arms every day for years and says he’s never seen this before. The history of the car prior to me purchasing it is undocumented but my forensic investigations tells me that the arm or arms had been serviced sometime in the last 49 years. Mostly because the rubber in the front bushings wasn’t blown out and the bolts had antiseize on them. The outside of the arms have plenty of surface rust, paint and grease/dirt buildup on them as evidence they’ve been on there for a looong time. The car has 116K miles on it, 5K of which we’re put on by me.
Have any of you ever seen or heard of a trailing arm being rebuilt without the spacer and shim? I dont understand how this came to be.
Thanks in advance for any responses.
Ken
Have any of you ever seen or heard of a trailing arm being rebuilt without the spacer and shim? I dont understand how this came to be.
Thanks in advance for any responses.
Ken
💯%,,,, Many have done work on C3s and really don't know what there doing..
Tech Contributor
Joined: Aug 1999
Posts: 15,175
Likes: 3,990
From: Connecticut, USA
I have seen it PLENTY of times.
Add to that:
The diff axle doesn't use a c-clip, they are snap rings and usually they don't fall off.
Typical reasons are:
Add to that:
- Axles with undersize journals- either from the bearing spinning or someone polishing them for slip bearings.
- Axles with threads mushroomed over and the nut forced on stripping the remaining threads
- Axles with cheap wheel studs
- Rubber bushings not compressed and staked
- Arms bent by an alignment guy or home hack
- Caliper brackets bent by using the tools many sell today
- Rotors undersize
- Rotted arms that were welded, creating welded, rotted, junk
- Parking brake shoes held on with hardware shoe springs and sheet metal screws
- Chinese bearings, cheap no name brand junk but the local chain store had them for $5 less than a quality USA or Japanese bearing
- Wrong caliper bracket bolts that scored the rotors
- new SS parking brake hardware that is just stamped out and not correctly fit- I deal with this all the time
- Bent support legs from hammering on seized shock mounts
The diff axle doesn't use a c-clip, they are snap rings and usually they don't fall off.
Typical reasons are:
- They are incorrectly installed
- Are the worn size
- Rebuilt axles were used and the groove not machined correctly.
- The worst is the axle faces worn down to that point and the ring fell off, that is over 3/16 of powdered metal floating in the diff and once the axle wears enough will crash into the housing and grind into it. I hope yours is not l like that and I hope you have good arms set up now.
Thread Starter
Pro
Joined: Aug 2010
Posts: 651
Likes: 452
From: Napa, CA
Thanks for chiming in Gary. I’ve read a lot of your stuff both here and on Digital and really appreciate the education. I used that knowledge to quiz prospective rebuilders. Last time I went through this exercise was 40 years ago on a 69 coupe and swore I’d never get myself into this situation again, and only allow myself to buy cars that have already had this work done. I’m confident that my stuff has now been corrected and look forward to driving it again by weeks end.
BTW my side yoke was fine, the snap ring had fallen off, not sure whether it was incorrectly installed or defective. The diff had obviously been worked on before as it has a drain plug in the bottom. Other than that it looked great inside and really clean.
BTW my side yoke was fine, the snap ring had fallen off, not sure whether it was incorrectly installed or defective. The diff had obviously been worked on before as it has a drain plug in the bottom. Other than that it looked great inside and really clean.
Last edited by 210ken; Apr 13, 2022 at 10:20 PM.
Melting Slicks
Joined: Aug 2016
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From: CLEVELAND STUCK IN OHIO
2024 C3 of the Year Finalist- Modified
