CV boot replace questions
 

I need to replace the outer boot on the passenger side. I have read a good bit but now just want to make sure about what I'm going to try. Also, figured I would replace the inner boot while I'm at it.

Can I just:

1. unbolt the inner CV from the tranny,
2. take off the inner CV joint & boot,
3. slide the outer boot down and the new outer boot back up,
4. Put the inner boot on
5. Regrease (no grease seems to be lost due to boot crack) and reattach everything?

Also, I have a couple new gaskets & Boots.
Should I order some new bolts as well? I noticed in several threads that most people replace the bolts while they are doing this. If so, where do I get the bolts?

I think it would be easer to take the shaft off entirely. Clean re-grease both CV joints reboot and put back on. Keeping every thing clean is the key. New bolts could not hurt while you are there. Remember to re torque after 200 Miles or so. Pretty straight forward. There are some excellent threads here on the procedure. I did the same thing last fall no problems. I think it would be a pain to leave the out board CV connected. It's a greasy mess get plenty of paper towels and disposable gloves.

There is a Ultimate CV joint replacement thread that is very good. A long read, but worth it. Bottom line, use new hex head socket to remove and re-torque, use Q-tips and brake cleaner spray with nozzle to get all holes clean and dry before you re-torque, use schnorr washers (they're like serrated lock washers), retorque after 100 and 500 miles, you will find some loose.

- use new Schnorr washers
- inspect each bolt very carefully - threads & the internal hex wrenching feature -- if OK, then you can re-use; no need to replace bolts each time

all can be had right here from Pelican - don't forget to buy new gaskets

Obviously you have the two piece boots: The rubber part is held to the thinnish steel collar with a metal band. There are also one piece boots, where the rubber is crimped into the steel collar and you have to replace both as a unit, which requires pulling the bolts because they go through the steel collar.

You know, I have never tried it this way (I favor the two piece system because I can use a universal boot with it), but I see no flaw with the theory in the abstract.

In practice, you may have trouble getting the inner CV off while working under the car. The snap ring is pretty stout, so I have always felt better working on that chore (removal, but also replacement) with the axle clamped vertically in my bench vise (with soft jaws).

And sometimes the CV does not want to slide off of the axle or back on and needs some persuasion. Much easier to do the persuading when things are held (or resting) vertically in a vice.

However, as long as you are prepared to remove the whole axle if you find you need to, nothing lost by trying.

There are two schools with regard to the bolts. One draws from racing experience, where everyone has lost a race and thus a chance at fortune (or something) because a five cent part failed. Those folks say replace the bolts - they are pretty stressed, are in a critical application, etc.

Then there are cheapskates like me. I replace these bolts only when the internal Allen hex has gotten buggered up. I've yet to have a bolt break when driving. They are a 12.9 grade, and pretty tough. 31 lbs/ft if a fair amount of twisting on an 8mm bolt, though Maryland Metric's max torque chart shows you could go up to 36.6 lbs/ft (I stick with 31, which works).

Speaking of the Allen: you've absorbed the standard advice, right? Clean out the holes very carefully. Maybe tap your socket tool to make sure it is fully seated before you start turning. Odds are very good that your bolts have the six sided internal hex. At one point and on some cars (914s, anyway) Porsche used a 12 point (sometimes called a tripple square) internal pattern. I happen to prefer that, but what is most important is that you match the tool with the fastener.

If you strip a hex socket in the bolt head, all is not lost. If just one, a vice grip and the wiggling of the whole CV once the rest are out usually does the trick. There are other tricks. Eventually we all get the job done.

As to length, if you purchase from our host they can tell you. Standard for the 911s from '75 through '84. 50mm.

Walt

Thanks for the info. Here is at least one issue. I do have the one piece cv boots on the car currently. I only bought the boots thinking they would work on the flanges once I cut the old boot off. Is this not the case?

If not, where do I get just the flanges. I don't see them in the catalog unless you buy the kit.
Which maybe in hind sight I should have.

Also,
I think I'm going to get the new bolts just so I know they are fresh. Do I only need 6 of these (911 CV Joint Bolt, 8x50mm (late 1975-early 85) - 900-067-211-09-M260)?

I don't see the washer you guys are referring to. Can you give me link? Do I need 6 of these as well?

Tom,

you are getting lots of good advice here.

my own opinion is to spend the bucks on the boots from Porsche. The simple reason is that they are cheap compared to the cost of cv joints. I also would buy the best high temp synthetic grease you can find. I like either Liqui Molly or Valvoline Super Syn grease.

your 1980 SC has the cv boots glued to the boot flange. The flange is the thicker style if your car has the original flanges still. You should buy the Porsche boot/flange, not the Volkswagon or Empi one in my opinion. The new flange is thinner and will require you to switch to shorter bolts. I forget the correct length. Just make sure that you see one or two threads sticking out the back of the cv joint.

Last, my own approach is to clean everything (cv joints, axles, bolts) in diesel fuel, then Super Clean, and finally Brakleen. You want to use disposable gloves. It's easier if you use a grease gun, either a small one that you refill with squeeze packs, or the big one with cartridges. Apply the gaskets to a clean and dry surface. Use plenty of grease. Use a dab of locktite on clean and dry bolt threads and tighten with a torque wrench.

Oh yeah, you can find the bolts in 12.9 strength rating at your local Orchard Supply Hardware. If you're thinking about working on the axles from underneath the car, don't. Take the axles to a workbench lined with newspaper. It's easier if you have a bench vise to hold everything upright with while you fit the axles and c clips together.

The cv joints are so expensive, and take so long to clean and pack with grease, I prefer to use the best grease I can get my hands on. And replace the boots at the first sign of hardening. Don't wait for them to crack.

Make SURE you get the 12.9 strength bolts, regular hardened are no good.

When I dropped my engine the first time I replaced all the bolts. I bought a whole box of them from MSC because I knew I would be replacing them every time... If you are going to replace them all the time I would suggest a whole box from a different vendor. The volume savings is significant. If you are just doing it once every 10 years or so, Pelican is your place. Though, I was able to get zink plated instead of the black oxide that are OEM (I believe).

+1 on the serious hex head cleaning prior to trying to unbolt!!

Best regards,

Michael

Tom

You may be out of luck trying to replace a one piece boot system with a two piecer. The two piece ones have a lip rolled into the metal flange which serves to retain the rubber part, along with the steel band that clamps it in place like a hose clamp would.

The one piece one in my picture is crimped, not glued, on - but maybe there are yet more styles out there. It lacks the external retention lip because they don't need a lip. So even if the replacement rubber would stretch to fit, you might find that you had retention problems.

Here is a picture of a one piecer. Also my favorite one size fits all replacement boot (for two piecers) from JCWhitney (NAPA used to carry as well, didn't 2 years ago).

http://forums.pelicanparts.com/uploa...1203289726.jpg

So you may need to bite the bullet and plan to take off the axle: remove the bolts on both ends, then drop the inner and pull the whole assembly out.

You are getting advice from folks who prefer to go through each CV each time they have one off the car. But that's your call. You don't have to disassemble, clean, inspect, reassemble, and repack each time you replace a boot. If your existing grease seems to be in good shape - plenty of it, and it is not all hard and crusted, you can just sort of top the grease off. CVs usually give plenty of warning when they are wearing out. You can wait until you start hearing a noise when turning in one direction at fairly low speeds, but not in the other. And then replace the CV. Usually you can run quite a while as the noise from a failing CV grows.

In short, you don't have to turn replacing one boot because of a tear into a project going through all four CVs.

But you may need to get a different replacement boot before you launch into this.

As to washers, don't worry about them. Grady likes them. They can't hurt. But the thick flange boot assemblies, which you have, don't come with them and you don't need them. They are called Schnorr washers, and have sharp radial grooves on each side. The idea is that when the bolts are torqued they will bite into the head of the bolt on one side, and into the other surface on the other side. And that this will cause a mechanical lock so the bolt can't rotate and come loose. Works if the steel breads on each side of the washer meat in the sandwich are softer than the washer. Makes using torque as a substitute for bolt tension a bit iffy, though.

If you are careful to keep mating surfaces pretty much free of lubricant, and torque properly, and then retorque after a couple of day's driving, you should be OK. As you can see, some folks add some Loctite. Some like the washers. If your car doesn't have washers under the bolt heads, you have proof that they are not essential.

Walt Fricke

I just wanted to follow up on this thread:

I replaced the cv boots on my friend's 911SC this weekend. The oem 911SC boots with the thick base plate are available again in kit form.

Also, I did some exploratory surgery on my 3.2 911 and took the axles off to check the condition of the grease. I think I'll be repacking my cv joints about every 2 years at minimum because the grease had turned to black liquid. I'd say I must drive about 10K per year on this car, in all sorts of weather, and the cv joints see huge summer temps in the 250+F range because I run my heater blower through the heat exchangers to keep them cool. I use Valvoline Super Syn grease that is supposed to be good for up to 400F.

Also, the red loctite was ok. Not a problem to remove the bolts as long as the bolts are clean and you are using a good allen tool. I reinstalled with new gaskets, clean bolts, and more red loctite.