Club 80-90 Forums

does anyone know the sizes of the socket head bolts that fix the driveshafts to the diff ? mine decided they wanted to break at 6 am today on my way to work, oh yes of course theyve sheared off leaving me a head ache!!! great. can i remove the diff drive easily to drill the broken bolts out? or is it a nightmare ? HELP

Think they're 6mm hex drive - sometimes equivalent 12 point star type drive and not really interchangeable cos you can strip the recess and get left with a bigger mess.
The drive flanges can be removed with the diff/box in situ but I'd try drilling them out in place first.

thanks mate, really looking forward to it!!!!

Just make sure you clean out the heads well before you try and undo.. also tap the socket/allen key into the head nice a firmly.. sometimes you only get one go....

If you fail to get them undone by gentle means:-

Grind off the heads with a grinderette. the CV flange will then move out away from the diff flange enough to get the grinder in between and cut through the remaining bits of bolts to allow you to remove cv. When you grind through the bolts make sure you leave enough to get a mole wrench on to get the stubs out of the diff flange. They normally come out of this fairly easily.

Drastic but will get the job done if all else fails.

Trundletruc

i wish it was that easy, but they have snapped in the threaded part(diff drive). the the studs i can just pull out of the cv bit, but there is a little part of each one in the diff piece, the drive shaft is just hanging loose, if you see what i mean ..

you may well find they will still unscrew... you can try tapping near the edge of each one at an angle with a sharp punch to "unscrew" them...

might be possible to use a "dremel" type tool to put a groove in each so you can get a screw driver on it...

Failing that.. pop the rubber plug out of the centre of the drive flange and remove the circlip, then pull off the drive flange (should need a puller for that) easier to work on a bench like that..
Oh,, you will prob have to drain the gearbox oil/jack the vehicle up on that side to make sure gear oil doesnt leak out though...

im going to drill into the bolts and unscrew them with some easy outs (later).

ToomanyToys wrote:you can try tapping near the edge of each one at an angle with a sharp punch to "unscrew" them...

That'll do it if you have sharp enough centre punch, even a scriber might get them turning, a fiddle but after a while thin nose pliers from behind. tap tap tap, around they go - hopefully.

Or just drill them out starting very small bang in middle (centre pop first) and as you go up in drill size might even spin them out, one way or the other.

Good luck

well its not too bad, only 3 have snapped, the other 3 must have rattled loose on their own (not ideal). it looks like a visit to west brom fasteners tomorrow, i think locking washers are in order too!!

If you use the 12 point cap heads supplied with new CV joints these days, torque them up in stages to 30~32 ft-lbf (no more!) and ensure both flange faces are clean to start with, there's very little chance they'll ever come loose.

Do not use normal spring washers If any, the ones supplied are usually hardened wrinkled/dimpled washers that have very little crush. I've not had any come loose that have gone in without them either.

The original torque spec for hex cap heads was 28 ft-lbf.

hows about using some threadlock with the new bolts...

Its undoing them again (sometime)...

Has anyone had any come loose or break that they themselves have fitted, and torqued up in stages to 30 lb-ft?

Is anyone doing bolt sets for these do you know?

Worth checking annually, just a visual would be better than nothing... its not uncommon for them to come loose, but most of it has got to be poor work, surely.

M6..?

what legnth do you want...may have some on the shelf. (stockist)

M8 x 48 (12-point spline drive) 24 for a 2WD

Syncro front inners (12 off)
M8 x 50 (12-point spline drive)

Washers
015 371 1 Lock Washer 8.4 x 13 x 0.8