How to change a broken halfshaft

by Annette Flottwell

We wanted to spend a day driving in the sand dunes of Parc du Marquenterre, but IT happened running up one of the first sandhills. Third low, race up, should be no problem with a V8. Should, I said, because we didn't make it. There was a strange crack, then the next attempt was as unsuccessful as the first. No front wheel drive, somebody observed. True enough, rear wheels spinned and nothing happened in the front. The only thing to do was get home slowly in 2WD hoping we wouldn't grind the diff to pieces. But there were no funny noises, so there was a chance it was not the planetary gear.

What you need

This is not a job for one afternoon, simply because you first want to know which halfshaft you snapped, then to phone around and organize a replacement. To order this replacement, you have to know first which type of halfshaft you got - 24 spline or 10 spline. Then there are homokinetics and universal joint type halfshafts.

You will need all sorts of imperial sockets and spanners for this fun, circlip pliers and a torque wrench. You'll need as well as a 2" spanner or socket. A replacement diff gasket is needed and you should provide blue silicone, then you also want to have some container at hand to drain swivel housings and diff.

Preparations

Jack up the axle and put it on stands, better use an elevator if at all possible. Put her out of gear, turn the driveshaft and see one of the wheels still turns occasionally. If it does, your diff is probably still alive, but you have probably snapped that halfshaft. To make turning the axle easier, get a pair of 9/16"s and disconnect the front driveshaft. See picture on right. The only way to find out whether you really have broken the diff or a halfshaft is to look in the diff. Before you get there, you'll have to dismantle a few parts. But it doesn't really matter, if a piece of the halfshaft is stuck in the diff, you have to take it out anyhow. Get rid of wheels and brakedrums and wiggle off the hubcap.

Removing the wheelhubs

Remove the split pin,the castle nut and a washer with the noble name of Spirolox, carefully collect all in hubcap.
If you've got a Stage One with homokinetic halfshafts, you just have to remove a circlip and pick up the washer.
Attack the six bolts where the arrow points to pull off the driving member. Check how much play it has in the splines, these driving members are not that expensive to replace. Don't forget to check for damage and clean off all the crap. Drain swivel housing, if you haven't done it yet.

Flatten the lock tabs which secure the 2" hub nuts, chisel recommended. Remove the nuts, get a drink and collect the thrust washer. Pull the hub off very carefully, making sure that you don't lose any bearings and place it on workbench.

Stub axle

Now remove the small angular bracket that holds the brake pipe behind the swivel housing. You don't really feel like disconnecting brake lines now, do you? Pull off anchor plate and cautiously place on convenient leaf springs. Now you can finally pull out your stub axle. It does no harm to check the oil seals now, they might explain why you had to top up recently.

Clean all surfaces that have to be sealed later.

At this point you should be able to pull out your halfshaft and admire the damage.

So where is the missing piece? In the diff, of course. See left picture below. That means that you have to remove the other halfshaft , when you come back from calling all your buddies, hoping someone has a halfshaft lying around. In our case, the broken homokinetic halfshaft was replaced by an ordinary uni joint type from a Series II 109. Please note that the Series Two type is actually less likely to break, the break lines in this form of shaft are not so deep into the surface. Yes, don't worry it really fits if you make some alterations which I'll put on the member's page one of these days.

But you have to look inside your diff first for possible damage. Leave the uppermost nut till you call for help, it is a bit heavy when you work overhead. And you don't want to drop it, do you?

After you have carefully removed the bit sticking in your diff, it is time to put it all together again. Replace diff gasket with a fresh one, and don't forget to apply blue silicone liberally to any other sealing surface. Fasten the brake line bracket as soon as you tighten the anchor plate. Replace the oil seal in the stub axle if needed. Check twice whether the halfshaft is really in the right position.
There is a very elaborate procedure in the workshop manual to adjust your hub end float to .05-.12 mm. Very easy with a watchmaker's tool (left)! We calculated this to be equivalent to a 15th turn back from tight. In real life, loosen the nut till your bearing doesn't feel to tight anymore. Hammer the lock tab back into position and fasten the outer hub nut. Check again if bearing is not too tight.

The driving member has to be torqued up between 42-56 Nm.

Don't forget to readjust your brakes when you're ready. Drive a test circuit of 10km and check wheel hub temperature. Check for leaks the next morning on your parking lot.

Drive safely!