Cannot get the half shafts out.

[Ian21401]

1992 940, 219,000 miles. Live rear axle.
Routine rear brake service so decided to try and replace the badly corroded brake back plates, replacements for which I have had since last year.
Dismantled everything and removed the four bolts which secure the shaft retaining plate and back plate.
Mr. Haynes does not mention the two bolts through the end of the axle casing and back plate which secure the housing for the handbrake operating mechanism to the back plate but I have that off also. Also released the handbrake operating mechanism from the handbrake cable so that is out of the way.
So everything is free but the half shafts will not pull out. I’ve tried Haynes suggestion of replacing the disc/drum the wrong way around and pulling but to no avail. I’m considering fitting a scrap disc/drum so that I can thump it hard and it doesn’t matter if it cracks etc.
Observations and suggestions will be welcome.

[Laird Scooby]

Originally Posted by Ian21401

1992 940, 219,000 miles. Live rear axle.
Routine rear brake service so decided to try and replace the badly corroded brake back plates, replacements for which I have had since last year.
Dismantled everything and removed the four bolts which secure the shaft retaining plate and back plate.
Mr. Haynes does not mention the two bolts through the end of the axle casing and back plate which secure the housing for the handbrake operating mechanism to the back plate but I have that off also. Also released the handbrake operating mechanism from the handbrake cable so that is out of the way.
So everything is free but the half shafts will not pull out. I’ve tried Haynes suggestion of replacing the disc/drum the wrong way around and pulling but to no avail. I’m considering fitting a scrap disc/drum so that I can thump it hard and it doesn’t matter if it cracks etc.
Observations and suggestions will be welcome.

Mr Haynes does mention removing the two bolts for the handbrake as part of removing the cable, i think it refers to that paragraph somewhere or at least did in mine which i happened to be reading earlier on the same subject. It is very easily missed though, especially when you have to keep flitting about from one section to another!

There is a wonderful tool called a slide-hammer that would be good or you could improvise one as you suggest with a scrap disc and a big hammer!

[Ian21401]

Thanks Dave.
I don’t possess a slide hammer. Once upon a time, in the 70s I think, I borrowed one to remove the half shafts on my Morris Marina for the first time to replace the wheel bearings, only to find out that a strong pull would bring them out.
I’m quite prepared to fit the scrap disc and give it some welly but a little concerned that I may damage the bearing etc. in the process. I suspect that after 27 years that bearing is fairly solid in the end of the axle case. As at present there is no trace of any oily contamination on the brakes I don’t want create another problem.

[Laird Scooby]

Originally Posted by Ian21401

Thanks Dave.
I don’t possess a slide hammer. Once upon a time, in the 70s I think, I borrowed one to remove the half shafts on my Morris Marina for the first time to replace the wheel bearings, only to find out that a strong pull would bring them out.
I’m quite prepared to fit the scrap disc and give it some welly but a little concerned that I may damage the bearing etc. in the process. I suspect that after 27 years that bearing is fairly solid in the end of the axle case. As at present there is no trace of any oily contamination on the brakes I don’t want create another problem.

You'd be wise to renew the oil seals at the same time anyway Ian, there is an inner one for the halfshaft then there is the bearing seat for the taper bearing (so no danger of damaing it) then there is the outer oil seal for the bearings.

YOu're almost guaranteed to split them when you extract the hafshaft as they will be dry from age.

From what i can make out from the HBoF, the halfshaft seal is smaller than the bearing seal.
The one thing i can't work out is what, if any, adjustment is there for the taper bearing and no nut to preload it either.
It could of course be that it's not designed to have a pre-load but relies on the correct fitting of the halfshaft to set the right distance for the bearing to have the correct clearance.

You could also cheat and cut a slit in the backplates, twist one side of the slit one way and the other side the opposite way to make a curly back plate then restraighten it after getting it onto the hub.

[Ian21401]

Thanks again Dave. Your appear to have your hands full with that back axle of yours. I’m with you on the energy and enthusiasm front but now the job has started it needs to be finished.
I’m aware of the inner oil seal and have two new ones to hand and appreciate that it would be good practice to renew them whilst doing the job but the old saying about “ if it ain’t broke “ springs to mind, but I accept your point about the old seal possible breaking so I think I’ll take your advice on that.
From the various info. that I have found it appeared to me that any work necessary on the bearing/seal assembly on the axle shaft itself was well outside my capabilities and equipment.
Having looked at the Haynes diagram again I see that the bearing is taper but the race/seat is a straight fit into the casing. I’d missed that.
I’m beginning to consider the cheat. Not quite sure yet where best to make the cut but the obvious place to me is the shortest section which passes through the hole where the handbrake cable mechanism fits. When refitted, the handbrake mechanism fixture, being bolted through to the axle casing would keep the area of the cut in place and there is also the actual retaining plate. The more I consider this the more I’m tempted. Originally I didn’t want to disfigure the new back plates, but given the possibility of disaster if I continue to try and pull the half shafts and the fact that even a cut new back plate will still be considerably better than what was there before I’m now giving it serious consideration .

[Laird Scooby]

The seals should be fairly easy from what i can make out but the bearing seat is another matter. Getting the new one in would be fairly easy, clean the hole up and polish it to ensure it's smooth then leave the seat in the freezer overnight, only taking it out at the last minute to fit it and then drift it in quickly before it warms up.

The seals can be removed by driving a self-tapper into them and then pulling with pliers or similar. Lube the new seals and drift them in with a socket or similar.

All that said, i think i'd go with the cheat, exactly where you suggest.

As for my back axle, i've found the answer to my conundrum so i just need to find a replacement M10 Nyloc for the chewed one on the prop/diff flange (or 4 replacements if it's slightly different in size/weight) and shift the old one somehow.

[Ian21401]

Cut through the old back plate at the point where I intended to cut the new plate then bent it to remove it, trying to think how I would reverse the procedure when fitting the new one. It wasn’ t easy and considerable patience was required. The nearside one went on quite easily but when I tried to replicate the method on the offside it was an absolute pain but it went on eventually as the light faded. Hopefully start reassembling tomorrow but will require a couple of replacement bolts to replace the ones with corroded heads. Problem there is I’ve got no transport so will have to try and find some in my used bolts box to replace the damaged ones for the time being. I’ll probably have every size other than the ones I require.
The damaged bolt heads had corroded badly. My flat drive sockets managed to deal with some of them. Since acquiring my flat drive socket set I tend to use it whenever dismantling but a couple of the bolts needed my recently acquired twist socket set. How did I manage without it. It has solved the problem on a number of occasions now but of course, there needs to be space to fit a socket and that is not always the case.

Dave, have you managed to free that nyloc nut yet?

[Laird Scooby]

Assuming you have sockets that will remove the bolts again Ian, here's what i would do.

It sounds as if you have two good bolts out of the four, am i right? If so, use the two good ones in the leading position (i'm guessing they are for either the calipers or handbrake?) on each side (that will be the lower of the two caliper moungting holes, the one a fixed point on the disc would encounter first if the disc turned in the normal direction of travel) and tighten them to the normal torque.

Use the two damaged ones in the top with a spot of Threadlock to prevent them coming undone as they need to only just be nipped up so you can get them out again without having a monster fight on your hands.

Measure the sizes of them before refitting, the brake caliper bolts will be High Tensile bolts, should have the grade stamped on the heads (8.8 is common but may be 9.2), if they're flange head bolts, the spanner size is usually smaller so an M12 thread with a flange head will have a 17mm head as opposed to the normal 19mm head.
I think (without checking so please check yours) the caliper bolts are M12 x 30 flange head, not sure on the handbrake linkage bolts but M10 x 25 flange head (13mm head) rings a bell.

Once you've got at least one good bolt in each bit each side, you can then drive carefully to go and get some replacements. Normal braking you'll be fine but try to avoid heavy barking.
If the supplier you go to sells a "patch bolt" variety of whatever the bolts happen to be, go for those, if not make sure you have some Threadlock as they caliper bolts at least need some on when fitted. Patch bolts come with a pre-applied layer of thread locking compound, activated when the bolt is used.

Haven't even tried to shift that bolt today, i did however manage to find a brand new, single, solitary M10 Nyloc - i have a bag of the things somewhere!
Also found a slim-walled 15mm socket which should just about fit on the head of the bolt the nut goes onto. With a bit of luck i can use that in my 12v Impact Wrench to shift the bolt and overcome the Nyloc of the chewed nut.

If i have any energy and enthusiasm tomorrow, i'll try to shift it early, if it moves then it's game on for doing the axle tomorrow, heatwave or no heatwave!

Might end up doing the same tricks with the caliper bolts as i've just suggested to you as well!

[Ian21401]

Having been caught out in the past, I try to keep a set of caliper flange screws in stock. Also guide pin bolts and front caliper bracket bolts. All courtesy of my main dealer to maintain the contact with them, and get some discount. They come patched.
The OE rear caliper flange screws are marked 10.9.
I couldn’t obtain direct replacements for the hand brake mechanism flange screws so I have followed Dave’s advice and will order some from my dealer asap.
What a pain trying to replace those hand brake shoes. I gave up today as the light was fading and my patience with it.

[Laird Scooby]

Pain in the neck those handbrake flange bolts Ian!!!
Turns out they're a 14mm head, only safe way of getting them is with a cranked ring spanner!

As you can guess, i've been having fun with mine today, took me nearly all day to get the old axle out, then when i continued at 7pm to try and get the new one fitted, it more or less jumped into place!
Still got the brakes and speedo sensor to refit tomorrow but aside from that, it's done!

I've worked out a method for refitting the shoes, not tried it yet but if it works as well as i think it will, i'll post it here for you.