1975 rearend issue
Thread Starter
Race Director
Joined: Dec 2003
Posts: 14,150
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From: Fremont Ca
2022 C4 of the Year Finalist - Modified
1975 rearend issue
I was doing some basic maintenance on my 75 recently and was shocked to find there is a lot of movement in the right side half shaft yoke. The yoke moves maybe 1/4 of an inch back and forth into/out of the housing. The rearend doesn't make any noise,zero,nothing coming from the rearend. What could be causing this? I'm positive the U joint isn't the issue,it's possible to raise the wheel up and down,while doing this it's possible to side the yoke sliding into/out of the rearend housing.
Race Director
Joined: Dec 1999
Posts: 19,610
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From: Forked River NJ
There are hundred of posts about this topic. Very common on C3 cars. The stub axle tip is worn down allowing the movement. It will require tear down of the rear and new or rebuilt axles. Look up ost from GTR1999. He is the guru on rears here on the forum.
Le Mans Master
Joined: Jun 2019
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From: Indiana
I was doing some basic maintenance on my 75 recently and was shocked to find there is a lot of movement in the right side half shaft yoke. The yoke moves maybe 1/4 of an inch back and forth into/out of the housing. The rearend doesn't make any noise,zero,nothing coming from the rearend. What could be causing this? I'm positive the U joint isn't the issue,it's possible to raise the wheel up and down,while doing this it's possible to side the yoke sliding into/out of the rearend housing.
https://www.corvetteforum.com/forums...ay-advice.html
Thread Starter
Race Director
Joined: Dec 2003
Posts: 14,150
Likes: 936
From: Fremont Ca
2022 C4 of the Year Finalist - Modified
Worn axels on a 12,000 mile car?
Tech Contributor
Joined: Aug 1999
Posts: 15,175
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From: Connecticut, USA
Some thoughts
- Is the diff original with 12k miles. If so, then it would be very unlikely the axle faces are worn. The case hardening lasted to about 45-50k miles before really starting to wear fast.
- If the car was run in the air the load on the diff or binding u-joints could pop off a snap ring and allow the axle to slide outward in suspension changes. The more wear and play in the axles will allow movement in the 1/2 shaft which is the upper link in the IRS. Also if worn the axle will crash into the diff and grind into it.
- If someone was ever into the diff then possibly the snap ring was installed incorrectly. Once in place the ring should not be loaded, it should be able to slide in the groove. One side of the ring has a slightly square edge and should be installed against the load side of the groove.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
