I am in the process of rebuilding all of my brakes, and while getting ready to this I noticed a particularly alarming problem. When I jacked the car and placed it on 4 jack stands, the rear right wheel (unloaded) pitches out much more than the rear left. The left side stays nearly vertical while the right seems to shift 5-10 degrees......is this normal?

The only thing that I noticed is maybe the trailing arm shims have rusted away and there is play in the bushing that is allowing the TA to rotate about its forward mount.

Should I be worried about this or can it wait until I rebuild the rear next year?

I will get some pictures tonight when I get home.

 

Sounds like the C-Clip has fallen out of the right-hand side yoke. You could conceivably drive the car that way, but it's not the safest thing. better to drop the diff, fish out the pieces, fix the cause, and have peace of mind. Likely a worn-out side yoke...

 

Camber is adjusted with the strut rods; toe is adjusted with the trailing arm shims. Having the car off the suspension isn't the best way to eyeball either.

Were you getting undue tire wear in the rear? Was the car twitchy?

 

Sorry if this is a stupid question, but can you further explain what you mean by yoke? Do you mean the U-Joints and Half Shafts? I am having trouble visualizing how this would cause the wheel to sit the way it does when unloaded.

There is no noticeable tire wear that is different from the left side. The car seemed to drive fine to me, what sort of twitch would there be?

 

This is why I object to the inference that a missing c-clip is a 'safety issue'. No, I don't want to hear the lecture about ball joints again from one of our other esteemed members.

 

The half shafts are part of the suspension system. With your car on jackstands up pull in and out on the top of the tire. If the yoke moves in and out of the differential the C-clip has probably come off of the end of the stub axle that goes into your differential. What Easy Mike means by "twitchy" is does the rearend feel a little unstable when taking curves at above average speed which can be caused by the stub axle moving in and out of the differential if the retainer clip is missing.

 

Mike... I'm glad you're on here. This should turn into something good. Ken

 

Mike, that all but sounded like an invitation.

You don't have to work in the trade for long before someone has their car towed in with the wheeling hanging half off from a separated ball joint, or the wheel missing altogether because the nuts came off, or the cv joint torn apart. Ask every one of those drivers and they'll all tell you they didn't notice anything amiss until the car flopped to the ground.

That's why safety inspections consist of more than a road test.

In the previous major go round about the need for the c-clips one of the members that lived in the eastern US mountains reported his car felt loose and squirrelly in the corners until he repaired his loose yokes. Another told of the noise from the yokes sliding against the pin.

Then there's you and the others that don't notice anything.

Driver observation is too inconsistent and unreliable to be a valid test.

I think my all time favourite in your no clips camp had to be the one where one of your supporters said that GM only put those clips on there as a safety precaution. Of course as such, they're not required for safe operation of the car.

Steve g

 

As soon as somebody starts waving the 'safety' flag I simply see visions of weeping mothers fearing for................the children.

 

And that's why fear mongering using the ball joint or wheel nuts or CV or _________ (fill in the blank) as examples is irrelevant and borderline irresponsible to state so. A worn yoke WILL NOT cause the wheel 'to hang half off' or separate completely. Once the worn yoke has reached the point where it is not longer being retained by the clip, it gets 'no worse' from an operational point of view. We will obviously always disagree to what extent a worn yoke affects the handling of a car. For every example you dig up of people who claim to notice 'something', I can find and equal or greater number who noticed no difference or who deliberately drive their cars with no clips.

Yes, the repair costs will rise dramatically if the dust shield chews into the diff housing but the handling itself will not unexpectedly change or will the car suffer from a sudden mechanical failure as it would with a ball joint or CV failure or wheel separation. Apples and oranges.

 

The point was not to suggest that the wheel would separate.

The point is that what the driver observes or does not observe has nothing to do with what the vehicle manufacturers, the government body responsible for vehicle safety and the industry sets as safety standards.

And what you set as safety standards are a far cry from what those bodies set. Ball joints and cv joints are condemned long before they are at risk of coming apart. Whether you agree with them or not, those are the safety standards.

Must just burn your *** to take your vehicles in for a mandatory safety inspection.

Steve g

 

Okay, so arguements aside, how easy is it to determine if the clip has fallen off?
Both sides seem to have noticeable play in the axis of the half-shafts if I push and pull on the trailing arm, does this mean both have fallen off. Since the parts seem to be cheap, there really isn't an issue for me to buy the parts, but how difficult is it to make the repair?
Does anyone have a good how-to on the forum for accessing these clips?

 

The clips having fallen off is only one part of the problem. The clips can still be there and the play exists. The yokes ride against the pin that the spider gears revolve on when the pressure is inward, outward pressure the c-clips hold the yoke against the axle gear and clutch pac.

Most of the excessive play is caused by the end of the yoke wearing. The shaft end will wear until it reaches the groove that the c-clip sits in then the clip comes off. Repair consists of removing the diff and replacing the yokes. A minor contributor to the play can be wear in the axle gear/posi clutch pac, but most cases replacing the yoke removes the slop.

Steve g

 

Yeah, I think it's been brought up at least once or twice in the last dozen years. Have you tried using the SEARCH function this forum provides?

 

Steve-

Each time this subject comes up, you specifically drag out the ball joint argument and the 'safety' aspect. If you now admit that the ultimate failure mode of a yoke is not comparable to that of a CV joint or ball joint, why keep using it? There's plenty of other things that will cause a failure during a safety inspections, a leaky muffler or burnt out tail light. Pick those instead- either can go unobserved by the driver and can pose a 'safety' issue.

It's virtually impossible to tell whether the clip has simply fallen off, was never installed in the first place, or the yokes have ground them selves into shortened stubs without significant disassembly. Yes the clips are cheap, but access labour and the potential for additional components replacement will drive the repair bill up significantly. As you noted, the car drives just fine. If you want to pull it off the road now and fix it or wait till later is purely a cost issue.

 

So, can I check the play in the yoke without remove the TAs and half shafts?
If it is bad should I drop the diff and do a rebuild?
If it is okay, just finish the brakes and get the car back on the road?

 

Mayor28, so sorry about all the ridiculous BS that invariably pollutes some of these discussions. To answer your question, you will need to pull the rear cover off of the diff to see what's in there, and you CAN look for play in the axle by pulling in and out on the top of the tire while watching the position of the side yoke relative to the differential case...if the yoke is moving noticeably, like, say, more than 1/8" or so, there is nothing retaining the axle laterally in the diff. You could concievably tell if the c-clip is missing by disassembling the right rear corner of the car and pulling the halfshaft out (or not; if the halfshaft won't come out then the clip is still holding it in). If indeed the clip has fallen out or broken or somehow worked its way off then it should be replaced; it's there for a reason. Unlike many other IRS-equipped cars (and later Corvettes, for that matter) the C3 uses the halfshaft as the upper locating link for the rear suspension and relies on that C-clip to keep the axle fixed in its lateral location. People can argue until the cows come home about
whether or not that was a good idea or whether or not it was effective or...whatever, but that's why it is there. TO HOLD THE AXLE IN PLACE, PERIOD. Again, can the car be driven that way? Of course. Is it "safe"? that's a judgement call, and as you can see by the brewing, oft-repeated argument here different peoples' 'judgment' tends to vary rather wildly. If you want to FIX THE PROBLEM you'll have to take the diff apart, fish out the broken pieces, replace the worn-out pieces (likely a side yoke, and check the left side while you're at it), and put it back together, likely needing to re-align the car in the process.

Don't mean to be the bearer of bad news, but in all likelihood that's what you're looking at. The parts aren't necessarily cheap, and there's all kinds of 'while-you're-at-it' issues involved with taking apart a C3 rearend (wheel bearings, etc., etc.) but the problem won't fix itself. best of luck whatever you decide...

 

Thats is what I am afraid of.........not to mention the sudden amount of scope creep......

 

And that's why the discussion about 'safety' needed to take place- to allow an owner to read up on some background information and make his own educated choice as to the urgency of required repairs.

It's very easy to cry wolf with any technical issue and hide behind statements like 'GM put them there for a reason and that's that' or infer that any discussion as heresy or ridiculous BS. A very pious attitude IMHO

 

Actually, I believe my initial reply to OP's question yesterday was reasonably succinct. I told him what the likely problem was and briefly what was needed to fix it. I didn't try to start a pointless argument or throw gas on a fire.

In my second post, I observed that this issue had had the crap beaten out of it on previous threads WITHOUT NAMING NAMES, primarily for the sole purpose of someone winning an argument and creating far more heat than light in the process.

If my observation somehow offended you then I offer my sincerest apologies. If trying to stick to the OP's subject constitutes "excess piety" on my part then I guess that's a risk I'll just have to live with...