CV Joint keeps coming loose AGHHH

If you use locktite, be sure to use blue not red. I don't have experience with this connection but lock washers seem to make sense. Did you torque the bolts to the proper spec?

Also, might want to get AAA or some other roadside assistance program.

 

This thread has some good pics and you can see lock washers are not used:

http://www.ferrarichat.com/forum/348-355/340378-355-cv-inner-boot-replacement.html

 

Maybe try new bolts and nuts. After a while they do stretch and I'm not sure what type are used on the cv joint I haven't been in there on mine but if it's nylon impregnated it should be replace after removal. As well as a self locking type once used and removed they don't self lock anymore. So if it has slots on it it's a self locking.

 

Never heard that before, perhaps we are talking different brands?

Threadlocking User's Guide|Adhesives vs. Mechanical Fasteners - Henkel Threadlocking User's Guide

 

Yeah it depends on the manufacture.

 

^^^^^^^^
Yep

Buy best you cab find

 

Are you torquing them correctly? Spec is 76 Ft Lb.

 

Agreed! You can take chances if you monitor closely. To the OP no disrespect intended but I think about installation error first. For example I can think of 4 things right off the bat. 1) mating surfaces not clean preventing proper mating and thus torque on surfaces, like having a dirt an a hub face and having your lug nuts come loose. 2)clicker torque wrench out of spec. Seen these new out of the box +/- 25%. Beam torque wrenches are best for consistent readings where wrenches are infrequently calibrated or never calibrated. 3) failure to snug up bolts in star pattern then tighten then torque in pattern similar to what you should do with wheel lugnuts. 4) failure to clean bolt threads and flange threads. CV joints are usually done clean and dry like lugnuts.

Then we do not know what Ferrari spec'ed for this application. For example these could be torque to yield bolts (TTY). If so they are single use. When they are reused and you get loosening of the fastener often that is the warning sign before they break. Many manufacturers use TTY in this application such as porsche and even ford. So Tim (SoCal1) is right use new bolts. When in doubt use new bolts. When you have an issue default to always using new bolts.

As a sidenote not in this case but other Ferraris use a nut and a bolt vs. a threaded flange. The nuts used there are "Prevailing Torque locknuts". They are also called flexlock nuts. These are used where there is heat and high vibration and shock loads all found in CV axles. They are also use once nuts. A single reuse will drop the prevailing torque 25%!

Racers fight CV joints coming loose all the time.

[ame=http://www.youtube.com/watch?v=oYdUbDl1Glk]Racecar Driver Nearly Hit by Flying Debris! NEAR DEATH - YouTube[/ame]

This is an example of what happens when an axle comes off. Sometimes if there is enough room between the flange and the diff you can get longer bolts and put a flexnut on there Too. It depends on several things but can be done.

In your case since the bolts came loose if there is not install error and if they are'nt TTY bolts then what does the flange look like? Did looseness of the bolts EGG out the threads in the flange so that you can never achive proper mating or torque. Do you have a non-concentric Axle that is producing funny harmonic vibrations that is loosening bolts? Check your axle concentricity. Is there enough play in your CV joint even if greased and maintained to contribute to a funny vibration? These things will prevent the CV axle from doping its job. I don't think you can fully inspect the flange without taking it out to get a really good line of sight on it.

Loctite! Loctite is not used in these applications by any manufacturer I know. I could be wrong. Locktite is a band aid. Loctite blue 242 and locktite red 271 have a max service temp of 300*F. It breaks down at 400*F which is done to remove 271 fasteners. I'm pretty certain that you will exceed the service temp of locktite in this application which is one reason racers who locktite still have problems with these fastners failing. Loctite is not recommended in this application.

 

I am surprised at that number so I looked it up and I am even more surprised. There are 2 lines, identical descriptions, identical fastener size 10mm x 1.25mm, one is 76 Nm, the other is 96 Nm.

I don't know what to think!

I would also recommend changing to brand new fasteners, and using blue Loctite, and fastening to 96 Nm.

The other thing that I have seen done on Porsche CV application is to drill holes into the cap of the fasteners and use safety wires. This is not a recommendation, but more of a possible idea based on other similar applications.

 

+1 ....... make sure everything is super clean, torqued properly and the bolts are not past their service life. Also make sure the mating interfaces are machine flush to each other, any possible warpage would create movement and would work the bolts loose. Also I do not recall if there are dowels on these but if there are, measure them to make sure they have a tight fit on both ends ........... and under extreme use ....... drill the bolt heads and install lock wire ..... that will prevent them from coming off completely ....

 

There are some interesting suggestions here. However, if installed correctly and properly torqued should this not be an issue? That the bolts are coming loose suggests something wrong with the reassembly. Perhaps the back cover on the CV joint is not seated correctly?

 

All I'll say is, I put those bolts on KING KONG TIGHT! Maybe it's the bolts in my 348, but I can torque on them using a cheater bar until they stop moving and they don't strip, nor do the heads pop off. They are some tough lil bastards.

 

The "trick" to getting these bolts to stay tight is to degrease everything carefully (bolts and nuts get a carb cleaner bath). I also give the bolt threads a spray with carb cleaner after they are in place (before the nuts are put on) just in case they picked up some of that damned grease when I put them through the CV joint. Tighten them alternately, carefully and check a couple times until you're sure they're tight. Loctite (blue or red) isn't a bad idea and would be insurance but won't do any good at all if the threads are greasy. The 355 is pretty easy to do because there is good access from above if you take a few things off first.

 

I have had to change the bloody inner CV multiple times and never had an issue with the flange bolts coming lose.

I'll probably get flamed for this, but I do as the two posts above.

Spotlessly clean, and F. TIGHT. in fact, I use my air gun on max.

Never had a problem, and have reused the same bolts.

Flame away!

 

Sometimes good and tight is the proper torque!

 

Perhaps but bolts get there clamp force by being stretched, the reaction to the stretch is the clamp.

Proper torque is always your best option, you do not want to over stretch the bolt.

When I worked for GM, we had very advanced fastening systems and they were based on torque + angle.

http://www.precisionenginetech.com/tech-explained/2011/05/20/tool-review-torque-plus-angle-in-one-tool/

 

regardless of the type of car, in our shop , we have made it a rule to always reuse the bolts. seems like the small amount of oxidation on the used ones keeps them tight. we used to use the new bolts that are supplied with axles and almost every time the customers car would get towed back in with the bolts falling out . if you want to use new, be sure they are oem , they have an etched surface that grabs a little better