C3 rear problem

[Keith Gangewere]

i have a 79 L82, 4 speed. the driver side u-joint yoke has excessive movement (side to side) to the point that i am convinced the yoke retaining ring is no longer in place on the yoke. with the sping unattached from the trailing arm i can pull on the wheel and the yoke will travel 2-3 inches in and out of the rear housing. this also has caused excessive wear on new trailing arm bushings, in under 5000 miles. in addition, each time i make a left hand turn from a full stop (yoke in question is on the left), there is noise from the rear. not a grinding noise, the noise appears to be a "strethcing" noise as if the traing arm was traveling farther than allowed. my questions are:
a) has anyone experienced the same problem
b) am i on the right track, or should i be concerned about other damage
c) is anyone experienced with this repair, if so can the repair be done

by removing the spring & rear cover with the rear remaining in the car

or does the rear need to be removed.
THANK YOU FOR ANY ASSISTANCE

[Tom Sarno]

Re: C3 rear problem

Keith,

The rear cover can not be removed without removing the differential from the car. I have always wondered if it is possible to remove the differential and leave the cover, spring and crossmember in place as not to have to deal with overly difficult crossmember cushions.

It is impossible for the c-clips to fall off with the carrier's cross shaft in place. I would suggest removing the half shaft at the side yoke and then try to pull the yoke out. If the yoke comes out then you will get a better idea of what is broken.

Tom S

[Jack Palmer]

Re: C3 rear problem

I have never had this problem, but if all you have to do is put on a new snap ring,I think you can do it without removing the rearend. I put a new spring and HD rearend cover on my '75 last weekend. First I lifted the car, and removed the spring , then I lowered the rear end enough to get to the top rear end mount bolts. Then removed the rear end cover. I was able to do all of this without removing the half shafts.

[Shannon Burgess]

Re: C3 rear problem

Tom, you can remove the differential while leaving the cover and crossmember attached in place. The procedure is outlined in the chassis service manual. Basically, you remove the front differential mount and the rear cover bolts, then lower the diff down and out. It isn't very easy to reinstall with the limited clearance around the battery and jack wells, but it can be done.

Shannon

[Joe L.]

Re: C3 rear problem

Keith-----

The problem that you describe is fairly common. In the VAST majority of the cases, it is caused by excesive wear on the end of the stub axle. Eventually, when the wear becomes extreme, the c-clip groove is "exposed" and the c-clip falls off. Then, the stub axle is no longer so-retained.

This sort of problem really means that it's rear end rebuild time. Remember, all that metal that has worn off the stub axles (the other one is likely close to as bad) has been churning around in your differential lube and bearings. Plus, for this much wear to have occurred on the stub axles means it's likely wear has occurred on other rear end components. You will also need to replace the stub axles with rebuilt or new reproduction axles.

Frankly, I do not recommend trying to remove the differential unit with the cover remaining in place. I think that it's FAR easier to remove the crossmember and drop the differential unit out with it. Notwithstanding the often stubborness of the differential end cushions seperating from the "sombrero" brackets, there are just 2 bolts that need to be removed. Thereafter, dealing with the differential unit is MUCH easier than with the cover still in the car.