CV joint leak

[lochrie2]

I was under the car changing the tranny fluid and noticed the CV joint on the passenger side is slinging oil everywhere, boot is not torn can the gaskets on the cv joint be replaced? I did clean the joint before the photo looks like the grease was coming out of the gaskets

[Targalid]

Flex the boot carefully and look for cracks with good light while rotating the wheel. If there are none, the boot should not leak. Look up and see if oil is dripping onto the boot from above or from the oil cooler, triangle of death forward of the boot.

[lochrie2]

its pretty thick black grease so I sure its coming from the CV joint

[RWebb]

somebody packed it too full and it is "seeking equilibrium"

when was it repacked? if long ago, the grease may be separating

[lochrie2]

Originally Posted by RWebb

somebody packed it too full and it is "seeking equilibrium"

when was it repacked? if long ago, the grease may be separating

Not sure, the car is new to me. Its a 1980 with only 13,000 original miles

[lochrie2]

I do know the engine was resealed about 7 yrs ago so they may have been repacked then

[RWebb]

Grease should last that long but maybe they did it and used some cheap grease

If you have OCD pull them out, clean, inspect and pack with Swepco. Be careful about using new Schnorr washers, cleaning male & female threads for the bolts with brake cleaner & Q-tips in the holes... Torque carefully after inspecting the threads and wrenching fixture on the bolts, and re-torque after 100 miles.

Otherwise, clean the grease off where it was slung; check boots for splits/cracks and drive until you hear noises...

[gtc]

If the gaskets are leaking, your CVs will move back and forth on the flanges, and it is only a matter of time before the bolts start backing out.
I would remove both axles, repack the CVs, replace boots if needed, and replace all gaskets.

[Walt Fricke]

As usual, I have a different take. First, torque the CV bolts. An '80 should have 8mm bolts, so 34 lbs/ft should do. I bet they are tight, as once any of them get at all loose, they can back out fairly quickly.

If loose, tighten.

Then, in either case, clean carefully, and wrap with the silver self adhesive tape body shops use. It is wide enough that one piece will cover all the way across the CV, across both joints, across the fat end plate or flange, with a little left over you can sort of crimp around the corner.

Also, where the boots are clamped to the axle, loosen or cut the clamp. Cut short pieces of the red plastic thin tubing which comes with carb and brake cleaner spray cans. Poke these short tubes between the axle and the rubber boot. If so inclined, reclamp the boot with a tie wrap - they are plenty strong for this job, as the boot itself is pretty tight on the axle. The tubes allow the CV to move in and out without creating air pressure changes inside the CV. Those have a tendency to push the grease out. Centrifugal force does, too of course. But there won't be enough force to get by your silver tape.

The gaskets for these CVs are flimsy, hard to get stuck on, and hard to keep grease off of on reinstallation. There is even a theory that one reason why the 100 mile or whatnot retorquing is so valuable is that at least one flavor of this gasket is a hair thick, and may not be fully squashed. When driving squashes it, now the bolt's stretch (torque) isn't quite what it should be. But some sealant like Honda/Yama bond is a simpler substitute, with the tape as suspenders.

All that grunge suggests your CVs may be low on grease. For the ones where you can see there have been leaks, whether just one or all four or whatnot, you can squirt some more CV grease in. Buy a sort of hypodermic like needle grease gun tool - it is a zerk on a thin steel tube. With the clamp cut off you can slide the needle in next to the axle until you get to the CV, and add some. Not too much.

There are places where you can cut corners, and places where you shouldn't. This is one where you can cut corners. A failing CV will give off noise you will hear long (a thousand miles maybe a lot more - the noise will tell you) before anything will fail and leave you stranded. Turn one way, no noise, turn the other, noise. That's a CV, or its a rear axle bearing going bad. The axle bearing will last a long time that way also (all this assumes you have a muffler). To get at the axle bearing you first have to remove the axle with both CVs, so you can disassemble them at that time to see if they are the cause of the noise before going on to the more difficult task of dealing with the axle bearing.

CV noise isn't like the idiot light coming on, and the oil pressure reading close to zero, while you are cruising down the highway and you have to stop immediately. With these bearings you can get to where you were going when you notice the noise.

Of course, if you want some experience wrenching, and don't mind the down time (and getting kind of greasy), by all means pull both axles and all 4 CVs off. Disassemble, clean, and inspect. Learn that there are two ways to reassemble - the right way, and a way which locks the joint and will have afraid you'll never get it apart again to re do it correctly. Replace any which are worn - plenty of posts on what wear is acceptable (shiny surfaces) and not (pits, can feel wear groove with finger). Figure out how to reseal. Decide if you are going to go by the book (like replace the bolts) or by the experience of some (reuse the bolts unless you have buggered the in-hex). And so on. Search this site for Grady Clay and CV - he wrote a whole essay on exactly how to do it right. I've done fine ignoring most of the details. Just get a decent seal and torque the bolts, then recheck just in case.

It took me longer than it should to realize all that crud on the starter motor was CV grease. The silver tape stopped that. Other methods work too, of course.

[lochrie2]

Originally Posted by Walt Fricke

As usual, I have a different take. First, torque the CV bolts. An '80 should have 8mm bolts, so 34 lbs/ft should do. I bet they are tight, as once any of them get at all loose, they can back out fairly quickly.

If loose, tighten.

Then, in either case, clean carefully, and wrap with the silver self adhesive tape body shops use. It is wide enough that one piece will cover all the way across the CV, across both joints, across the fat end plate or flange, with a little left over you can sort of crimp around the corner.

Also, where the boots are clamped to the axle, loosen or cut the clamp. Cut short pieces of the red plastic thin tubing which comes with carb and brake cleaner spray cans. Poke these short tubes between the axle and the rubber boot. If so inclined, reclamp the boot with a tie wrap - they are plenty strong for this job, as the boot itself is pretty tight on the axle. The tubes allow the CV to move in and out without creating air pressure changes inside the CV. Those have a tendency to push the grease out. Centrifugal force does, too of course. But there won't be enough force to get by your silver tape.

The gaskets for these CVs are flimsy, hard to get stuck on, and hard to keep grease off of on reinstallation. There is even a theory that one reason why the 100 mile or whatnot retorquing is so valuable is that at least one flavor of this gasket is a hair thick, and may not be fully squashed. When driving squashes it, now the bolt's stretch (torque) isn't quite what it should be. But some sealant like Honda/Yama bond is a simpler substitute, with the tape as suspenders.

All that grunge suggests your CVs may be low on grease. For the ones where you can see there have been leaks, whether just one or all four or whatnot, you can squirt some more CV grease in. Buy a sort of hypodermic like needle grease gun tool - it is a zerk on a thin steel tube. With the clamp cut off you can slide the needle in next to the axle until you get to the CV, and add some. Not too much.

There are places where you can cut corners, and places where you shouldn't. This is one where you can cut corners. A failing CV will give off noise you will hear long (a thousand miles maybe a lot more - the noise will tell you) before anything will fail and leave you stranded. Turn one way, no noise, turn the other, noise. That's a CV, or its a rear axle bearing going bad. The axle bearing will last a long time that way also (all this assumes you have a muffler). To get at the axle bearing you first have to remove the axle with both CVs, so you can disassemble them at that time to see if they are the cause of the noise before going on to the more difficult task of dealing with the axle bearing.

CV noise isn't like the idiot light coming on, and the oil pressure reading close to zero, while you are cruising down the highway and you have to stop immediately. With these bearings you can get to where you were going when you notice the noise.

Of course, if you want some experience wrenching, and don't mind the down time (and getting kind of greasy), by all means pull both axles and all 4 CVs off. Disassemble, clean, and inspect. Learn that there are two ways to reassemble - the right way, and a way which locks the joint and will have afraid you'll never get it apart again to re do it correctly. Replace any which are worn - plenty of posts on what wear is acceptable (shiny surfaces) and not (pits, can feel wear groove with finger). Figure out how to reseal. Decide if you are going to go by the book (like replace the bolts) or by the experience of some (reuse the bolts unless you have buggered the in-hex). And so on. Search this site for Grady Clay and CV - he wrote a whole essay on exactly how to do it right. I've done fine ignoring most of the details. Just get a decent seal and torque the bolts, then recheck just in case.

It took me longer than it should to realize all that crud on the starter motor was CV grease. The silver tape stopped that. Other methods work too, of course.

I will give that a try thanks for the great advice!

[lochrie2]

Well upon further investigation ALL of the 8mm hex bolts were loose tightened them up to 30 ft lbs looks like I caught it soon enough that no damage was done! will squirt some more grease and be on my way. Thanks for the help!

[TechnoViking]

Listen to Walt. Avoid reinventing the CV joint as suggested by so many previous threads.

[lochrie2]

Walt,

Any recommendations on a good grease gun for the job?

[gtc]

"There are places where you can cut corners, and places where you shouldn't. This is one where you can cut corners."

Wow, that is bizarre advise. I've had these bolts back out and an axle come loose on one end... it was not cool. Luckily it was the outboard side, and the cavity in the trailing arm kept the axle from flailing around and causing damage.
I later read the Grady Clay thread and took greater care when installing the axles. No leaks or loose bolts since then.

[gtc]

Originally Posted by TechnoViking

Listen to Walt. Avoid reinventing the CV joint as suggested by so many previous threads.

I would say that using a vent tube, sealing tape, and silicone flange sealant is reinventing the CV joint...

[Walt Fricke]

I guess I'm just a bizarre guy.

I've had way more experience with CVs than I would have liked. Doing my own engine or transmission rebuilds, replacing axle bearings when they started making noise, having race motors blow up (though I have worked on leaving the transmission in to avoid messing around with the CVs), and pulling CVs to check for wear has given me plenty of experience. Plus the inevitable torn boot here or there.

The crowning experience (clowning experience?) was my hollow axles experiment. They weighed less, and had a longer splined section, with no ridge at its medial end for the CV to butt up against. What that meant was that the wheel had a larger range of motion, which for off road use was important. In my case, being able to shove the axle farther toward a wheel when lining the inner CV up with the transmission flange was easier, especially on my GT car, which was converted to long wheel base aluminum banana arms on a formerly SWB tub, with 935 camber boxes to boot - I had to have the transmission mounts loose to move it a bit side to side to get the end of the axle past the drive flange.

The kicker was that these hollow axles broke. Not right away, but after some number of races they would. Didn't cause more than cosmetic damage, and not the disaster that an inner CV coming unmoored would be, but disabled the race car. The first time that happened I drove a long way home in the support vehicle, and did the swap at night with a flashlight, to get the stock one. Of course, I kept using the other one, and bought another set, the designer having told me that the spline inner ends had been adjusted so as not to be stress risers. I installed those, keeping the still good one, plus a solid axle, in the trailer. In the fullness of time, one of the new ones broke - great. So I installed the spare old hollow one. When that broke, I replaced only it with a stock axle. And when the 4th one broke, I was finally done with these, though the concept of losing weight on the neutral axis is naturally attractive - race car weight reduction is, to use a metaphor, a game of inches.

But I got fairly quick at all this. Once an axle let loose toward the end of a qualifying session. When I saw how good my time was it was elbows and those other things, and I made the grid in time - wasn't going to lose that position. One thing I have done is to switch from hex allen bolts to 12 point/triple squares - the bit holds much better, and I've never had a problem buggering the grip, even when in quite a hurry. I use a 3/8" air impact to spin them off, and to install them not quite to torque, following up with the torque wrench. Holding things in place with a knee or leg on the tire saves needing an assistant or otherwise spending time.

Back when I was using the stock gaskets I once had one bolt back out a bit, but the 100 mile or whatnot check caught it. If you don't get things tight enough, I don't believe Schnorr washers are going to prevent that. Carroll Smith didn't believe washers could help keep a bolt in place (He didn't know about Nordlocks, but those are not just a washer).
Those two hole washer/plates? Porsche sometimes used them, and sometimes not. A good washer will help keep the bolt head from squashing the thin steel of the boot flange, but that can be dealt with. Bolts which aren't stretched beyond their elastic limit can be reused - done all the time with high strength rod bolts in an application far more torque/stretch critical than the CV. Worried about old grease getting on the bolt threads? Why? For rod bolts, a lubricant is always recommended. Yes, with no lubricant you have to twist harder to achieve the same stretch than with lubricant, so 34 lbs/ft dry is going to be higher with lubrication. Not enough to exceed the elastic limit, though. Anti-seixe is a sort of lubricant, but it is a good thing where fasteners are exposed to water, so they can be unfastened with no more force than was used fastening them.

Which is why I have paid attention to what is the quickest and easiest way of dealing with CVs, and tested short cuts, and having found them satisfactory, get on a soap box on the subject.

Mind you, there is nothing wrong, in any sense, in following Grady's approach, or as some guys like, using Nordlocks or the like. But nobody should be under the misapprehension that there aren't other ways to do the job.

[gtc]

No offense intended by my posts above.
There are certainly plenty of ways to skin this cat, but suggesting that it is OK to have a cavalier attitude about something that could potentially cause an unsafe situation is probably not the kind of advise we should be giving on this forum.
Suppose the bolts let go while he's pulling out in to traffic or crossing a road, leaving him coasting though oncoming traffic?

[ClickClickBoom]

Guys,
This subject comes up every year. There are a lot of “old wives tales” about CV joints. This is a thread about the subject, with more than a few posts from the late great Grady Clay. Reconstructing Constant Velocity (CV) Joints
I had a CV come loose, from less than surgical attention to detail and from reading this thread so have many others. This is common if the process is corrupted. The 8mm bolt 100mm CV is at the design threshold for the bolt size. This being said, if you read this thread, follow it explicitly, you will have no problems.
I was less than careful about cleanliness, and lost a CV because of it. I have 60,000 trouble free miles, with more than a few CV R&Rs, mostly due to boot failure.
There are only 2 absolutes, first, absolute surgical cleanliness of the CV and stub axle interface, that means nothing, including skin oil from your fingertips, the second is bolt torque and maintaining it. Everything else is technique. Locking processes of bolts and fasteners is dry, and boring, right up to the point the axle comes off and beats the crap out of everything within its reach, then it’s exciting and expensive. If anyone has had more than one CV come loose, they aren’t doing it right and the flaws in their process need to be identified and modified.

[Superman]

IMHO, this requires extraordinary care and attention to detail. If an inboard CV joint detaches, the axle can (will) flail about, at speed, destroying expensive stuff. Some 911 owners have been known to use safety wire on the bolts. I would not regard this as overkill. At a minimum, maintenance and installation should be done precisely to factory spec.

[Walt Fricke]

If I were concerned about properly torqued CV bolts backing out, I'd use Nordlocks or the like.

For an race car engineer's view of safety wire, read Carroll Smith's Nuts, Bolts, Fasteners and Plumbing Handbook. He wrote it before the advent of Nordlocks, I believe, and alas isn't around to update it.

He says safety wire will not prevent a bolt from loosening. Its presence does indicate that the mechanic most likely tightened the bolt before wiring it, and it prevents the bolt from backing all the way out and being lost. And even if the head breaks off, it keeps it (if in something internal) from causing more harm.

The forces of a bolted rotation joint are transmitted from one side to the other by the compression of the two halves together due to the stretch of the bolt, for which torque is, in the case of CVs, about the only practical substitute. Maybe the angle method would be a bit more accurate, as in head stud nuts? But the same degree of equal tightening can't be as important here - just at least the minimum needed, and a bit more here or there doesn't matter). The shear strength of the bolts themselves is not what does the job. Hence great care to get enough torque.

I haven't seen an engineering analysis of lubrication on such a joint, but it seems logical that surface friction is part of the joint strength equation, as it is with brake pads and rotors and stopping power. Dryer would require less compression to do the job. But as long as you don't torque the bolt beyond its plastic limit, it will do the job - and these bolts don't see additional tension beyond what the torque creates, do they?

I wonder if that was involved in Porsche's decision to friction weld the outer CV to its drive flange? Is the grease added later? Or does the friction method allow the heat to be created so quickly and so localized that by the time it gets to grease in the CV it is within the grease's limits? In any event, one of the advantages of the "replace the whole assembly" systems is that you only have to worry about the inner CV bolts and joint.