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Constant Velocity Joint on a 1990 Geo Prizm

Hello,

I’m working on my 1990 Geo Prizm which was in a minor accident. The right front strut was bent and the insurance adjuster from the driver that hit me said he was sure the steering knuckle would be bent if the strut was. Even though I doubted him I decided to replace the knuckle rather than do all the other work and then find out when the alignment is done that it was indeed bent.
With everything disassembled, I could see there were deep cracks in the outer CV boot. There were no splits all the way through so I thought, fine, I’ll just replace the boot.
The problem is that I can’t get the joint off the axle. I have the official shop manual for the vehicle and it says - and shows in a diagram - that there is a snap ring that must be removed to get the joint off the shaft. I don’t see a snap ring. There is a groove in the axle shaft that is just covered by the inner race where a snap ring could go, but there would be no way of removing it since the groove is covered and can only be seen at the ends of the troughs that the balls ride in. Besides that, I don’t see how a snap ring on the shaft that is inboard of the joint would keep the joint from sliding off. The replacement boot came with a round (in cross section) split ring like the ring on the inner splines of the axle. With no snap ring, I expected that the joint would pop off the end of the axle with a strike of a brass hammer - but no! I cut a piece of very hard wood to use as a punch and really pounded on it with a heavy hammer, but it wouldn’t come off. Next, I used two split plates - like for pressing bearings - one next to the joint and the other clamped tight to the axle shaft where there is a taper it could grip and used a pair of bolts threaded through one plate to push against the other plate. Still won’t come off! - and it’s pushing quite hard.
How do I remove this CV joint? I’ve considered trying to get a split type boot that glues together at a seam, but would really rather use a conventional boot.
Any other words of wisdom?
Thanks in advance,
Rich

Me, I’d leave it as is, keep an eye on it, it if gets to the point that it’s split and making noise on turns, then I’d replace the entire axle.

The outer CV-joint might not be serviceable even if the manual says so. Sometimes the manufacturer will make a mid-year design change to a component. So you may have to replace the entire halfshaft.

Tester

You remove the inner CV joint. There is a snap ring on the backside of it, be sure to remember which way it is oriented. Then you remove the inner boot, then the outer boot, sliding it all the way down the axle.

Get a Toyota mechanic to fix it-Kevin

There was a call to the show about a similar problem. The fellow couldn’t find the snap ring, so he used a hacksaw to remove the CV joint. He said it took him 6 hours or something! Ray told him there was in fact a snap ring and there was no need for all the hacksawing!

I think there is a snap ring but you just havne’t seen it yet. I’m assuming you have the entire shaft out on the bench. Usually you have to do that before you can take the CV joint apart. Remove the existing boot of course by pulling it back or cutting it off. You’re going to replace it anyway. (I wouldn’t attempt to re-use it if it has visible cracking.) Sometimes you have to clean everything off very thoroughly with a solvent, then you have to twist the joint this way and that, but eventually you’ll see the snap ring. Another idea, take the other side off and see if you can see it on that side. You need to replace both side’s boots anyway. If after doing this you still can’t see it, take the entire shaft to the Toyota dealership (or to a shop who specializes in Toyotas) and ask the guys there to show you where the snap ring is. Most of the time they are happy to offer guidance gratis, as long as they don’t have to do it themselves of course.

It’s highly unlikely your snap ring was never there or has disappeared. But I guess it is possible. In that case the part that is supposed to pull off could be corroded a bit and stuck on. Again, the guys as the Toyota dealership should be able to offer some guidance. In that case, my first bet would be a hammer and a brass drift.

Texases, your suggestion might be most practical, but since it is all taken apart it seemed reasonable to replace the boots now. Also, I tend to get stressed out over things I think are about to go bad, so it would be good for me and the car to fix it. Additionally, I’m a cheapskate so I want to fix things while they are still cheap.

Tester, I suppose if the joint was put together with a square-shouldered split ring it might not pop apart. Being, fundamentally, a Toyota I expected everything to be serviceable. The axles aren’t horrendously expensive if that’s what it comes down to. There seems to be a choice of new or rebuilt so that probably means they can be serviced. To satisfy my own curiosity, I’d like to know how.

Keith, that is a really great idea. I’ll plan to do that tomorrow. Still, I’d like to take the outer joint apart to do a better job cleaning out the original grease. I may have to settle for just most of it - or a major solvent wash.

GeorgeSanJose, the axle is out of the car and grease is wiped away from the joint so if there was a snap ring I’m sure I’d see it. Probably should say I would hope I’d see it.
Six hours with a hacksaw? A cutting torch or angle grinder would have been much quicker.

Thanks to you all for the advice.

Rich

Then I’d just go buy a replacement axle. They’re not that expensive.

Have you tried looking for a snap ring on the inner joint followed by removing the inner joint and then replacing the both inner/outer boots?

Many axles allow the removal of the inner joint but the outer joint is not designed to be removed from the shaft for service. Keep in mind that I’m no Geo expert and just basing my comments on what I’ve worked with in the past.

Around here a single boot kit is 20-25 dollars. A halfshaft from AutoZone is 48 dollars with an exchange. I’d just get an axle and be done with it.

Six hours with a hacksaw is either pure insanity or the sign of someone with infinite patience and a large supply of blades.

Ditto on replacing the axle as a unit. It’s going to cost less to replace it than taking your wife out to dinner. It’s not worth the time, frustration, or questionable outcome to try and fix it.

I found a youtube video ( http://www.youtube.com/watch?v=sX8jM4TuGsQ ) that showed a CV joint rebuild where both the cage and inner race had to be destroyed in order to remove the joint from the shaft. It’s a different vehicle than mine. For me, the take home message is that sometimes the only way to remove the joint is to destroy it - which I’d like to avoid.

Rich

Since I already have one outer boot kit I will probably do the one side where the axle is already out of the vehicle per Keith’s suggestion and either do nothing on the other side until the boot rips or get a rebuilt axle now.
And regarding 6 hours with a hacksaw, using a grinder or a cutting torch would be much more fun.

Rich

Great video, Rich. I’ve never seen anything that showed that clearly how an outer CV joint is constructed.

Thanks a million.

I looked at the AllData diagram, the components go (from the end of the outboard shaft) deflector ring, outer race, case, inner race, balls, axel shaft snap ring, outboard boot.

So it appears there is a snap ring on the outboard side. But the AllData doesn’t appear to say anything about replacing the outer CV joint, only the inner.

Perhaps because they’re not intended to be field repaired.

My car is an early 90’s Corolla – for the most part a twin of the Geo Prizm – and I have changed my outer CV boots without removing the axel shaft from the car. So I must have been able to disassemble the outer CV joint in order to get the new boot on. But my car isn’t a 1990 Geo Prizm, so there may be a difference between how the two vehicle’s axel shafts are configured. Or the OP’ers car may not have its original axel shafts.

The instructions for the 90 Geo Prizm (engine code 6) are sort of ambiguous, but mtnbike appears to be correct in saying that the outer CV joint is not designed to be taken apart and cleaned as a part of routine service.

The drawing for the 90 Geo does show a snap ring on the outer CV joint. See the drawing below. And the drawing seems to include instructions on how to at least remove the balls from the outer CV joint, see below.

DISASSEMBLY

Secure axle assembly in a soft-jawed vise.
Remove boot retaining clamps, Fig. 11.
Remove race retaining ring using snap ring pliers.
Disconnect inner race from drive axle shaft.
Remove boot from axle shaft.
Tilt cage, then remove ball bearings.
Tilt cage and inner race 90°, then pull from outer race.

Here’s some of what I’ve done and learned. Keith’s concise suggestion is what worked: Remove the inner boot and joint, remove outer boot and replace as necessary. With the axle out and cleaned up I am absolutely sure there is no snap ring that allows the outer joint to be removed. Even though I had a replacement outer boot on hand, I shouldn’t have bothered with the job. I think It would have been better to do nothing and wait until the axle actually went bad or replace the axle preemptively. As I was going through the process of taking the axle apart it occurred to me that it would be practically impossible to clean all the old grease out of the outer joint. There is probably a good sized reservoir of grease outboard of the joint in the cavity of the axle stub that can not be wiped off. Cleaning solvent would be very difficult - no, impossible to get in there to wash it all out. That would leave a mixture of old grease and solvent along with the new grease in the joint, possibly causing the joint to fail. I skipped the cleaning solvent part of the process and just put in some fresh grease along with the new boot knowing there was a chance the greases would be incompatible and cause the joint to fail. If I had realized sooner that the outer joint couldn’t be disassembled I could have at least reserved the old grease and put it back with the new boot and not needed to add the new grease.
One thing that seems like a possibility is that this axle may be a replacement for what came from the factory. Perhaps an aftermarket or rebuilt axle is held together differently than the original. That would explain why the book is wrong for this unit.
Hindsight is always so much better.

Rich

You have made all the right decisions. The grease in the CV joints does not go bad or break down, there is not enough heat generated by these. Because the grease stays fresh, there is very little wear on the joint. If it weren’t for the type of rubber used on CV joint boots, they could last for 20 or more years. But they use a rubber that breaks down in 5-10 years. A urethane or silicone rubber would last so much longer.

When the boot splits, the grease gets out and dirt gets in and that is just like taking a grinding wheel to the joint. They will wear out in days or weeks. The outers usually go first.

The grease used in CV joints is almost exclusively a Moly-Lith grease so what you used is probably compatible.

Today, you can get brand new replacement axles from China for about twice the cost of the boot kits alone. Considering how much work is involved, I’d say thats a bargain, although once you get the axles out, rebooting isn’t that hard and doesn’t take all that long, especially if you don’t use solvent in the joint.

Since it is done, your axle should be good for another 5 to 10 years, depending on the rubber the boot is made from.

Rich … I think you are right, that the original axel that came with the car new had the removable snap ring on the outer joint, but along the way this axel has been replaced by one with the new configuration, which has no snap ring. My Chilton’s manual says this occured in 1993, when they changed the configuration from one that you could remove the outer CV joint, to one where you can’t. I assume there’s a reason for this, maybe the removable ones were causing some reliability problem of some sort or another.

If you had the original drive shaft, I would recommend you keep it, and replace the outer boot by removing the outer CV joint with the snap ring. The reason to try to keep the original is there have been quite a few complaints here in the forum about rebuilt drive shafts being defective right off the bat. But since you don’t have the original, it’s six of one or half a dozen of the other. You can either just get a rebuilt drive shaft and install it. It will have the new boots on both sides and nothing more to do than install it. Or you can replace the outer boot from the other side, as described. I don’t see one way being better than the other.

If you decide to keep the old drive shaft and just replace the boot, as far as cleaning all the old grease out, that probably isn’t critical to success. You’d just clean it the best you can, then put in new grease, and replace the boot. I wouldn’t use a solvent, because if you don’t get all the solvent out, any remaining inside the boot will eat away and weaken it, and you’ll quickly be right back where you started. It’s a good idea to always try to keep solvents off the CV boots when possible, either on the outside or the inside.

Best of luck.

as far as cleaning all the old grease out, that probably isn't critical to success.

That is true only if you replace the boot before it gets ripped or torn. Even a few hours of driving with a torn boot will contaminate the grease and destroy the CV joint. If you go this route as George has suggested, do it before the boot splits open.