Topic: How to Replace Rear Diff Side Yoke Axle Seals
in Forum: C3 Driveline Components
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I’m asking this question about my '82 (but it would also apply to an ’80 or ’81): Does anyone know if it's possible to replace the rear diff side yoke axle seals with the batwing and diff still mounted in the car? Mine are leaking gear oil, and seem to be getting worse. The oil drips onto the exhaust system, and it smells pretty bad. It looks like you might be able to remove and install the seals by just removing the half shafts, which would allow you to pull the yokes out of the diff, but I don’t know for sure. In any case, do you have to actually get inside the diff to do this job, or will the yokes just pull out once you remove the half shafts? In other words, do you have to separate the carrier from the batwing?
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you will have to pull the diff cover off to get the shaft yokes out.
cthulhu 2007-02-10 12:32:44
they have a snap ring that holds them in.
if they come out without this... you will need to pull your diff case anyway.. as the ends of the yokes are worn enough that the snap rings have fallen off.
I had one yoke with a snap ring still on it when I tore my car apart.. then other was worn so far that the ring couldnt stay on.
they are a major PITA
Thanks, cthulhu. I was afraid of that. The only thing is, I see that you have a '69, which has a different type diff than an '82. Do you 100% know that what you say applies to the newer design diff assemblies that are on '80-'82s? The only reason I'm questioning is that I have the GM service manual for my car, and the blowup drawing of the diff internals does not show a snap ring, C-clip (as on many other GM cars), or anything else that looks like an axle retainer.
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i do not know for certain that it does, anyone with a late c3 that can clarify?
Ben is correct.
Darryl81 2007-02-10 17:06:02
There are indeed snap rings that hold the yokes in place.
You will need to drop the whole rear end out of the car due to the fact that the "batwing" is the cover and is also the structure that holds the rear end in the car. Along with the front pinion mount of course.
If you have access to a lift and are pretty good with a wrench, it should take you around 1.5-2 hrs. to pull it out. And after you get it resealed, it will take at least 2 hrs. to get it back in.
And yes I have had my rear end out and apart 2x's. Once to reseal the original 2.72 diff. And once more to put in a rebuilt 3.08 diff out of an '80 for a little more "uumph" of the line.
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Well, thanks for the bad news! (Just kidding!) Seriously, thank's for the straight skinny. And now, since I know I gotta do what I gotta do, I also will install a lower ratio gearset while things are apart.
Luckily, I do have a mid-rise lift in my garage, so at least it won't be a particularly difficult chore, and there will be no absolute rush to get everything done all at once. I'm also sure it will turn into one of those "well, while I'm in this far, I also might as well..." jobs. Will probably rework the half shafts, etc. Maybe even replace the T arms. I'll assess the condition of everything once I'm in, and decide what further should be done. Thanks again!
redvet
If you could give us an idea of how much a PITA it turns out to be it would be appreciated. Mine is leaking on the passenger side and I typically like doing my own work, but this looks difficult.
Good luck, gurtz
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The 'luminuminum diffs are much easier to remove than the earlier ones, but still not exactly a barrel of fun. By the time you got the batwing/cover off, you would only have a couple more items to remove to have the whole mess out, so it makes more sense to just remove it all to start with.
Once the diff is out, and the cover removed, changing the yoke seals involves removing the yoke snap-rings, then the yokes. The seals can then be replaced. Be sure to keep the yokes on the same side as they were removed from, as well as the snap-rings. The snap-rings are "selective", meaning there are several different thicknesses, to allow adjustment of the free-play of the yokes, which should be in the range of....none.(or VERY little)
Check the ends of the yokes for any sings of wear where they rub on the center pin of the diff. This is where they will wear, and the snap-ring falls off, as Ben mentioned.
It is best to measure the amount of play in the yokes before removing them. That will at least give you some indication of wear on the yokes, or the posi clutches. If either or both are worn, this would be the time to remedy the situation.
Once the diff is out, and the cover removed, changing the yoke seals involves removing the yoke snap-rings, then the yokes. The seals can then be replaced. Be sure to keep the yokes on the same side as they were removed from, as well as the snap-rings. The snap-rings are "selective", meaning there are several different thicknesses, to allow adjustment of the free-play of the yokes, which should be in the range of....none.(or VERY little)
Check the ends of the yokes for any sings of wear where they rub on the center pin of the diff. This is where they will wear, and the snap-ring falls off, as Ben mentioned.
It is best to measure the amount of play in the yokes before removing them. That will at least give you some indication of wear on the yokes, or the posi clutches. If either or both are worn, this would be the time to remedy the situation.
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in Forum: C3 Driveline Components
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