Removing a broken diff - stuck!

[jammy_basturd]

I'm currently trying to remove my broken diff and I've become stuck at the last couple of bolts (typical).

I managed to get the top diff mount bolt out (ironically this was one of the easiest ones). The only bolts left is one propshaft bolt (right at the top), and the two top front mounting plate bolts.

I cannot turn the propshaft to get to the last bolt, plus it seems that both the nut and the bolt are slightly rounded off as I can't get enough room/purchase on either to loosen them. Without getting the last propshaft bolt out, I cannot remove the propshaft and thus I cannot get enough room to remove the last two mounting plate bolts.

Anyone have any ideas?!

[mattrosersv]

I guess there is a reason you can't turn prop shaft round?

When I did mine I jacked up one rear wheel and used a combination of a socket on a wheel nut + me turning the wheel (so as not to over torque the wheel nut) which was enough to turn the prop, with box in neutral of course.

This was on a ramp which made it easier.

Matt

[Jhonno]

Can you remove the prop from the box end?

[jammy_basturd]

Can't turn the propshaft as the diff is completely borked, as in the diff won't turn at all (well, maybe 10 degrees, but it's not enough).

I don't think I can remove the prop at the gearbox end? As far as I'm aware the only way to remove the prop is to move the bolts from the diff flange, drop that end of the prop and then the prop slides out of the gearbox.

[esso]

Can you not get in to cut the nut off the bolt ?...with a angle grinder or suchlike.

[scotty_d]

I doubt you will get the prop shaft out the gear box side with it still fitted to the diff it has to slide at least 100mm back out the gear box. Sounds like a tricky one, Since the diff is fked any way i would try and force it round with large breaker bars make something up that extends out so you can force it i would not do it on the drive shafts in case you damage them.

[jammy_basturd]

I don't think I would get an angle grinder into the space above the prop, let alone manoeuvre it to cut the nut off.

I think I'm just going to have to keep trying with spanners. I've got some crows feet spanner ends that I might try.

I don't think I'd be able to force the prop around. When the diff went it locked up both wheels at 20-30mph, it took a pick up truck to move the car on a two rope, with both wheels still both locked. Plus, the car is just on axle stands, so I've got about 12" to play with under the prop - I don't think that would give the necessary leverage to forcibly turn it.

[aide]

Maybe taking off the diff cover and freeing it up internally would help?

[jammy_basturd]

Oooo, didn't realise that was possible with the diff still in the chassis and the propshaft still attached. Will definitely look into that.

[Noisy]

I'm not sure if there would be the room, but I often use an electric impact gun to undo the propshaft bolts, you could possibly use a couple of extention bars to move the gun into a position that makes it possible to use?

[jammy_basturd]

Noisy said:

I'm not sure if there would be the room, but I often use an electric impact gun to undo the propshaft bolts, you could possibly use a couple of extention bars to move the gun into a position that makes it possible to use?

Not sure how exactly you mean? I can get a socket on to the prop flange bolt head, but it has a small amount of rounding on the head, so I can't get enough leverage on it. I think trying to use an impact gun would only worsen the situation. I'm a big fan of my impact gun though, did the top mounting bolt in 10 minutes with it!

I can't think of any way in which I could use the impact gun to turn the diff?

[LuckyLucky]

Noisy said:

I'm not sure if there would be the room, but I often use an electric impact gun to undo the propshaft bolts, you could possibly use a couple of extention bars to move the gun into a position that makes it possible to use?

Good idea, with someone else to hold the bolt head..

[Brummmie]

You have knocked the flanges out already?
Can you slack the bearing holders off, i know these themselves can be corroded in, but mine turn by fingers now its been apart.
It may provide enough space in there for whatever has locked up to become free.

[ridds]

If you get really stuck you could also knock the cups out of the UJ to allow you to remove the prop. There are 2 retaining clips either side of the each yoke, remove these and then knock the cup into the yoke. Remove the cup that's been pushed out then knock the centre back the other way.

I'm not sure shaft position your UJ is in but may help in access the dodgy bolt.

Again not sure on clearance but these are VERY effective.

[pmessling]

I thought the very same Matt about the uj's.

Worse comes to the worse cut the prop. But that would be the worse case.

[Noisy]

jammy_basturd said:

Not sure how exactly you mean? I can get a socket on to the prop flange bolt head, but it has a small amount of rounding on the head, so I can't get enough leverage on it. I think trying to use an impact gun would only worsen the situation. I'm a big fan of my impact gun though, did the top mounting bolt in 10 minutes with it!

I can't think of any way in which I could use the impact gun to turn the diff?

Often I've found if the bolts have rounded a little try using a 6 sided socket rather than a multipoint socket, my extension bars allow a small amount of movement to position them slightly out of line of the prop but still be properly on the head of the bolt so I can then use the impact gun to undo the bolts.

[jammy_basturd]

Yea, I've tried using my hex socket, but they are slightly thicker walled, and the head of the bolt sits inside a bit of a recess on the inside, so the thicker walled socket gets even less purchase on the bolt.

I've tried dismantling the UJ now, got the clips out, but I can't get enough room around the UJ to drift the cups in/out.

I've made progress though, I managed to undo the backing nut on the top mounting bolt for the front plate on the drivers side, which then allowed me to undo the hex bolt. So the passenger side front mounting plate is off, which has allowed me to move the diff around a bit. I've now got a much better view of the last remaining hex socket on the pass. side, but the backing nut is remaining defiantly hard to undo. I think once I managed to get the other front plate off, I'll be able to rotate the diff round to move the propshaft bolt around to be able to get it out.

[pmessling]

Good luck mate getting it out. Whilst I've removed the diff twice now it's easy enough whilst its free but yours sounds a pig. Sounds like good progress.

Remember you need to turn it near enough side ways to get past the chassis rails.

I found lifting it on my chest easier to get it out. Then slide it off your chest onto the floor.

[Nickccc]

If you don't manage to get the bolts, nuts off, I have a spare propshaft that you can have if you do find cutting yours the only option.

[jammy_basturd]

Thanks Nick, that's a very generous offer.

Bit more progress. With the movement in the diff from taking one front mounting plate off, I managed to get the impact gun on the last bolt on the other mounting plate. I freed it off just enough to be able to move a spanner on the backing nut, followed by a very tedious and tiring half hour putting everything I had into undoing the backing nut. Once that was off it was literally 20 seconds to let the impact gun do its work on the bolt.

So now both mounting plates are off, bit it seems I was wrong in my assumption that with them both off I'd be able to rotate the diff around - the rear top mounting bracket just sits on the chassis cross-members and completely limits any movement.

I can now get a spanner on the nut for the propshaft bolt, but again no leverage to undo it.

So I guess tomorrow I'm going to have to try and find a way of removing the top bracket, see if I can get that hex bit in the sockets, or clear out some of the corrosion.