Club 80-90 Forums

Im considering replacing all my CV joint bolts with something like these ones ....

http://www.vwparts.net/CVBOLTS.html" onclick="window.open(this.href);return false;

or this ....

if your worried about them comming loose just drill a hole through the top of the allan bolt and lockwire it to the next bolt. always use the wire so that if the bolt undoes the wire tightens.

..lee.. wrote:if your worried about them comming loose just drill a hole through the top of the allan bolt and lockwire it to the next bolt. always use the wire so that if the bolt undoes the wire tightens.

We used to do that to the CV joints on the Formula Fords ....

Would loctite or similar help?

This is what you need ..... tis good stuff

Got to wonder if it might be possible to redesign the bolting system up to aircraft spec,
If this sort of thing was happening in the sky it would need serious rethinking.
I havent really thought about it but seen things like drilling and wiring through in the old days.
Any ideas?

I am no engineer and know hardly anything about mechanics really but if you pop thread lock on and torque all the bolts up exactly the same they shouldnt come out should they? Its all very well you doing them all up tight but if they are all at different torque settings and spinning round a good un all the time they are going to come out eventually arnt they?

I have to admit I am guilty of just tightening them up until I feel they are right but it isnt really is it.....

I have a torque wrench now so if anyone knows the correct settings maybe we can just go out and do what we are suppose to do and eliminate the paranoia maybe.

jed

45Nm - 33ftlb - don't use locktite unless you have a set of irwins or you may not get them out, especially in the field doing a shaft change at an event, which does happen

the only one's I've had any issues with are the crap silver multisplines supplied with the cv boot kits - they aren't 8.8 afaics, I've sheared two torquing them up (shear at end of thread so not correctly made), and they do seem to come undone even when torqued - I think they just have crap threads - I'd rather reuse the genuine ones if possible, they are 10.9 - quality nowadays especially of steel parts doesn't seem to be as good imho - I think that's because we sold all our scrap to China and they mixed it all up and made cheap crap and sold it back to us

I swapped a driveshaft when reinstalling the syncro gearbox recently for a used/good GKN refurbed one as the n/s inner cv was sloppy. I made a point of checking the bolts and making sure the serrated lockwashers were all there. The bolts were 10.9 grade 12 spline. The ones that were on this side had 8.8 hex socket bolts and several were stripped - I then had to bring the angle grinder into play...
What surprises me is that VW thought that 33 lb.ft was adequate? They always seem to be very tight when removing oem bolts (I undo a lot of bolts on a daily basis, no limp wrists here)
I second Aidan's opinion on loctite, it would be impossible to get the threads perfectly clean for it to cure on assembly and a field repair would turn into a nightmare.#

PS. Drilling the heads of 10.9 cap screws for lockwire is not a diy option. They are brick hard and you need a pillar drill at the very least, better still a Bridgeport BRJ (Andrew knows what one of these is )
We do this op as a matter of course when refurbing pre-war Jaguar ENV diffs, but still manage to break the odd drill

Just nipped my front inners up, a couple needed a slight tighten before it clicked at 45mn

I think that the CV bolts get polished by taking them out and putting them back in again, this makes them more liable to come undone, especially when the threads have lots of LM grease on them. I am sure that VW would not have used grease when assembling the CV's on the bolt threads and they sort of rust themselves tight. Frequent reassembly loosens everything up if you see what I mean.

For that reason I use new bolts, and dont go crazy on the grease.

Simon.

Propellors on aircraft are lock-wired on like this (random pics from the internet)...



with these…



A lot of track and enduro race bikers also lock-wire on various bolts like oil filler and drains.

A bit overkill really. Like Jed and Simon say, clean non-greasy new bolts correctly torqued and periodically checked should do!

everything gets lockwired on rally cars. it works and when you have 10mins to change a gearbox your not faffing around with tight threads due to lockthread.

I have always used the spline heads with thread lock and never had any problems undoing them. I do have one of the extra long spline tools though which makes the job a doddle for the inner ones, also I have never had any come undone when threads have been cleaned, thread locked and torqued to 45nm, and I have done a few.
Rob.

Preventive maintenance springs to mind! After working for an oil exploration company in the middle east/north africa etc.running Kenworth 6x6 trucks the main priority was to stop "bits" coming undone thus causing possible extensive damage.Tie wire is not the answer as in can let the bolt loosen enough to cause extensive damage ,can stop bits flying out the back of racecars though????? (Massa not included)