Rear diff housing, HELP

Hello all. Been the proud owner of a three door, 300 tdi disco for about 4 months and i'm slowly sorting her out. Within two weeks of getting her the clutch fork impaled itself on the pivot. Gearbox out new fork, complete clutch and gearbox / crankshaft oil seals all replaced and the world was rosey again. Till last night when the rear diff decided to spew its oil all over the drive. After inspection it appears that the tin cover that covers the rear of the diff had rusted away and turned into a sieve. I have now purchased the offening item and was wondering if any of you guys knows how the hell you (1) get the old one off? and (2) put the new one on? By the way my truck (94 on a L plate) is averaging 35 to the gallon and seems to have a lot more power than my fathers newer 300 tdi. not moaning mind you. Is this about right? SID

the diff pan requires welding on, 1/remove diff from axle casing 2/grind off old leaking cover 3/mig weld on new pan making sure that the crownwheel protrusion is on the correct side and spot on vertical 4/ refit diff top up with oil and pat yourself on the back for job well done. Or failing that fit a good seconhand axle!

or wash it out with petrol, tap in the edges of the hole and use metal mastic to fill the hole.

The Mad Hat Man said:

or wash it out with petrol, tap in the edges of the hole and use metal mastic to fill the hole.

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thats wot yella did with his, it fell out and i then welded it. i can talk mine is using a litre of oil per 500mile

stig said:

thats wot yella did with his, it fell out

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nuff sed

Thanks for the feedback, sounds like a saturday morning job to me. Now where did i put that lump hammer?

if yu are going fur the metal mastic option - dont tap the cover in too far because the diff aint far away from the cover - A small piece of foil or summat on the inside helps give the repair a bit more substance. Make sure it is oil free too - a good washing in petrol worked for me.

Air chisel the old one off after draining whats left of the oil,then mig the new cover on and paint it properly.Takes about 1 1/2 hrs to do properly and then the diff will not die.

Unless you're very competent with the welder, this is a job best left to a professional. You're welding thin sheet to the thick metal of the axle and it's a bugger to do without warping the new cover and/or blowing holes in it and/or not getting an oil-tight seam.
Just had my front one done by my local Indy fer £100 - top job too.

Hi sid, this happened to mine too. I had 2 attempts to fix - the first I used fibreglass repair and it was a disaster! So don't do that.

2nd attempt was to use bridging compound, which has strands of fibreglass in it and is used to bridge holes in rusty bodywork usually. It comes as a lump of squidgy stuff with some hardner in a small tube.

Anyway, drain the oil, clean all the rust off the bad area, then build up a couple of layers of the bridging compound over the holes and extend it round the diff cover a bit and smooth it off so it still looks curved. Then paint and refill with oil. Job done. This repair has lasted 2 years so far and shows no sign of deterioration yet (and no leaks).

Good luck whatever way you go...