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I have some movement on the left rear tire, if you push on the caliper it moves back quite a bit, I thought it was the wheel bearing but after removing the tire and rotor I think it's possibly the mounting brackets?? I don't think is a bearing because it's not like the wheel is moving inside the housing, but the housing moving on the car. I took a video, the link is https://youtube.com/shorts/5cDNRxgAh5g?feature=share it could also be the link from the spring to the housing but it doesn't seem like that would really hold it any help is greatly appreciated!
Looks like the stub axle is moving in and out, apparently there is a retaining clip that fails on these models. My reason for suspecting the bearings to begin with was shaking while driving, I suspected the front end and from what people are saying some guys don't even worry about the clips. Would they be causing my shake? Should I replace the half shafts or just get new clips? It looks like most of the work is in removing the rear cover to replace the clips anyway, any recommendations on replacement shafts? Apparently they wear out so a good set would probably be worth the extra $.
I tried to watch your video but got seasick, sorry but I couldn't see much.
You have a 79, if it has never been worked on, and worked on correctly, then you have worn out axles, poorly setup posi and possible ring gear bolt concerns. Add into that, weak clutches used from 72-79. Now if someone has worked on since 1979, all bets are off.
You have some options, none of which are to continue using the car as the axles will crash into the diff and chew up the seal, if that hasn't already happened. Look at the diff at the axle seal bore, there should be a 1/8" lip there. If you don't see it then it has been ground off by the axle. If you can posi pictures looking at the axle into the diff I can tell you more.
1- you can repair the diff, which sounds like your thought process. That is assuming you get good axles, as new and rebuilt today have issues. More than most here know about.
2- You can rebuild the diff. If you can do it and know what to do that is great. Otherwise, you better do your homework real good because the offerings today are,... well interesting to be nice. The mistake most people who don't know about these cars make is to price shop, going with the lowest price they can find- big mistake. I have been doing this work for 45 years now and have repaired the work of just about most of the rebuilders out there, from local garages, speed shops, vendors, etc. Some do a good stock job, which isn't the best. Others do less which isn't much either. Not that long ago many places were owned by individuals, today more and more are being bought out and things are changing. Many places now don't rebuild them they just resell what they get from a shop pumping them out as fast as possible for the most money.
If you are sure it is the differential, I would remove it - pull the cover, drain the oil and take a look before you decide on anything.
A good point to my comments - a few weeks ago I got in a vette diff, rebuilt by a vette shop. It was seized up. Once I got the posi out, I found it was painted. You never paint a posi case, no need. Removing the paint I found it was sleeved and welded. Removing all the paint I found a 2" crack in the posi case. It is junk. It cannot be repaired, and it was not an accident by the rebuilder. It was a cover up that in time would have reached the cross shaft and imploded the diff. Beware of some of the websites out there. Some of them are some of the biggest crooks in the game.
Correctly built, the axle endplay should be 005-007" with an overrun to 010" max. I am often asked about rebuilt diff's guys got and found endplay of 020-030-040" or more and if it's good? No, it is lousy. I just went through a dozen used axles today in fact, checking them in a tuned posi, all worn past the 010" endplay limit. I will rebuild them and reuse them rather than try to get new or rebuilt today. That's how I do them, others may not or may not say which is a huge red flag too. Or say, they're built stock, if someone can't tell you how they build parts, they either are not building them or cutting corners as some here have been burnt by over the years.
With the backend up on jackstands grab the suspecting tire at 12 o clock & 6 o clock. See if the excess movement is the stub axle or trailing arm.
Check the bracket that holds the strut rods too. If the bracket works its way loose, you will have excess side to side play also. That makes for a scary ride with camber all over the place. The bolts that mount the strut rod bracket must have Loctite Blue applied.
The stub axle retaining clips take a pounding. Eventually the stub axle will "mushroom" and or the clip will snap off. I bet there are thousands of C3s w/o the clips.
Supposedly if the clips stay in the bottom of the differential, they pose no issues. If they get tossed up into the ring gear . . . . .
We have a differential expert on here. He will likely chime in soon. As in one minute.
Figured you might think I am over the top, I'm just tired of the expensive, lousy work out there today. So, here is the painted posi I spoke about above for those who think I might have exaggerated.
I tried to watch your video but got seasick, sorry but I couldn't see much.
You have a 79, if it has never been worked on, and worked on correctly, then you have worn out axles, poorly setup posi and possible ring gear bolt concerns. Add into that, weak clutches used from 72-79. Now if someone has worked on since 1979, all bets are off.
You have some options, none of which are to continue using the car as the axles will crash into the diff and chew up the seal, if that hasn't already happened. Look at the diff at the axle seal bore, there should be a 1/8" lip there. If you don't see it then it has been ground off by the axle. If you can posi pictures looking at the axle into the diff I can tell you more.
1- you can repair the diff, which sounds like your thought process. That is assuming you get good axles, as new and rebuilt today have issues. More than most here know about.
2- You can rebuild the diff. If you can do it and know what to do that is great. Otherwise, you better do your homework real good because the offerings today are,... well interesting to be nice. The mistake most people who don't know about these cars make is to price shop, going with the lowest price they can find- big mistake. I have been doing this work for 45 years now and have repaired the work of just about most of the rebuilders out there, from local garages, speed shops, vendors, etc. Some do a good stock job, which isn't the best. Others do less which isn't much either. Not that long ago many places were owned by individuals, today more and more are being bought out and things are changing. Many places now don't rebuild them they just resell what they get from a shop pumping them out as fast as possible for the most money.
If you are sure it is the differential, I would remove it - pull the cover, drain the oil and take a look before you decide on anything.
A good point to my comments - a few weeks ago I got in a vette diff, rebuilt by a vette shop. It was seized up. Once I got the posi out, I found it was painted. You never paint a posi case, no need. Removing the paint I found it was sleeved and welded. Removing all the paint I found a 2" crack in the posi case. It is junk. It cannot be repaired, and it was not an accident by the rebuilder. It was a cover up that in time would have reached the cross shaft and imploded the diff. Beware of some of the websites out there. Some of them are some of the biggest crooks in the game.
Correctly built, the axle endplay should be 005-007" with an overrun to 010" max. I am often asked about rebuilt diff's guys got and found endplay of 020-030-040" or more and if it's good? No, it is lousy. I just went through a dozen used axles today in fact, checking them in a tuned posi, all worn past the 010" endplay limit. I will rebuild them and reuse them rather than try to get new or rebuilt today. That's how I do them, others may not or may not say which is a huge red flag too. Or say, they're built stock, if someone can't tell you how they build parts, they either are not building them or cutting corners as some here have been burnt by over the years.
Good luck.
The car has been modified front to back, I know the gear ratio has been changed I'll have to locate the service records to verify exactly what to. Hopefully some new clips will be the answer. I'll post pictures inside the diff when I get it pulled out.
New clips are not going to resolve axle endplay. If they fell off they were not installed correctly or were the wrong size. If they came off from wear as many times they do, the axle is worn down well below the case hardness depth of 030" and more likely closer to 180".
However, maybe you will luck out. We now know someone was in the diff, and that is always interesting.
Why? If the clips are worn down and the groove is gone seems like I would need new ones? I can always return them if I don't need them it saves me a week of kicking around a diff waiting on parts.
Why? If the clips are worn down and the groove is gone seems like I would need new ones? I can always return them if I don't need them it saves me a week of kicking around a diff waiting on parts.
79 rear wheel movement
