Help, Diff Leak problem!!

I have found what looks like a puncture hole in the side of the diff! Oil is all over the drive and the car stinks! Its a 2004 TD4, its done 85000 miles. Can this be welded up or will i need a new diff? Also can i drive it? Or do i have to get it towed to a Garage??

Cheers!

Hmm.......I certainly would not drive it for fear of damaging it (possibly further).

I would have thought that a competent welder could plug weld the hole, depending on the size. I would take the welders advice as to whether to leave the oil in it (to act as a heat sink) or drain it prior to welding. Of course, if it is left in, it should be totally drained and replaced after the repair.

If its cast, I wouldn't have thort any welder would touch it, it's a bitch to weld at the best of times.

On the other hand, why not use some mesh and liquid metal? As long as its all clean it should work, we use it on engine sumps, so it's oil resistant.

Yes, mesh and liquid metal might, as there's no internal pressure. However, that's why I emphasized COMPETENT welder, as a good welder with the right rods can weld cast.

hxsw said:

I have found what looks like a puncture hole in the side of the diff! Oil is all over the drive and the car stinks! Its a 2004 TD4, its done 85000 miles. Can this be welded up or will i need a new diff? Also can i drive it? Or do i have to get it towed to a Garage??

Cheers!

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Yes.......... and if you searched just this week it was done with photos

mick 1986 said:

If its cast, I wouldn't have thort any welder would touch it, it's a bitch to weld at the best of times.

On the other hand, why not use some mesh and liquid metal? As long as its all clean it should work, we use it on engine sumps, so it's oil resistant.

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#1 not true piece of cake welding cast

#2 rather African engineering there, will fail

Thor1950 said:

#1 not true piece of cake welding cast

#2 rather African engineering there, will fail

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From my experience cast is a pain in the arse. I only use MMA/SMAW, so that's probably why I find it difficult.

Why is it African engineering? Will it fail because you didn't think of it, or because you have done it wrong and it's failed in the past? All the sumps, and fuel tanks for that matter, have all worked fine for me.

What about epoxy resin, ie Milliput?

I think the question should be.....what caused the puncture first?
Is it from external or internal damage.......I would want to at least drop the diff and remove the back plate to see what's gone on and check there's no shrapnel floating around in there.

mick 1986 said:

From my experience cast is a pain in the arse. I only use MMA/SMAW, so that's probably why I find it difficult.

Why is it African engineering? Will it fail because you didn't think of it, or because you have done it wrong and it's failed in the past? All the sumps, and fuel tanks for that matter, have all worked fine for me.

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expoxy does not stick to steel very well, The granular characteristic of steel is very fine and does not allow proper adhesion to steel, also there will be some oil in the pores of the steel, impeding the chemical reaction of epoxy to adhere itself.

the question do a search, keeps the PC bunch at bay

With cast iron proper preheat, interpass temps and post heat. stress relief are required for welding cast iron. Have welded cast iron heads and cast aluminium heads the were cracked from HFG and also a Cat 350hp 6 cylinder diesel that threw a rod out the side of the block.

Thor1950 said:

expoxy does not stick to steel very well, The granular characteristic of steel is very fine and does not allow proper adhesion to steel, also there will be some oil in the pores of the steel, impeding the chemical reaction of epoxy to adhere itself.

the question do a search, keeps the PC bunch at bay

With cast iron proper preheat, interpass temps and post heat. stress relief are required for welding cast iron. Have welded cast iron heads and cast aluminium heads the were cracked from HFG and also a Cat 350hp 6 cylinder diesel that threw a rod out the side of the block.

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Me thinks there must be some eastern European in you somewhere as we normally give them cracked blocks, heads etc when they go home for a week and they bring them back looking like new

mjrimmer said:

Me thinks there must be some eastern European in you somewhere as we normally give them cracked blocks, heads etc when they go home for a week and they bring them back looking like new

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Just good Yanky with brit roots, god this is along time since 1970 welding.

took lots of attempts on cast oxy,act gas, them stick arc, and then playing 1 day with a tig torch and bingo phosbrozne rod or bare nickle rod

key is pre heat and any prep work grinding out crack and drilling hole at each end of crack to keep it from running on was the trick. Then clamping head to a jig/frame before you put heat to it. a heat treat oven works the mutt nuts for all the heating and stress relieving cast iron or aluminium just different heat for each other

stich welding is what they use on cast ,But a hole, have you been near a golf course where some has got a hole in one.LOL, as said look on the inside thats more likly to be the cause i would bin it and get another.

I have had another look this morning, it looks like something inside has broken. Im now worried about what could have caused it. Could the VCU have locked up and broken the diff?

Does it stink of gas? If so the diff has overheated, this will be due either tires being mismatched or tight vcu

Yes it smelled of gas, i had a pair of new tyres put on the back about a month ago, would this cause it to blow a hole in the diff?

hxsw said:

Yes it smelled of gas, i had a pair of new tyres put on the back about a month ago, would this cause it to blow a hole in the diff?

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Theres a good chance thats what caused it, the overall circumfrance will be too larger difference between the fronts and caused the VCU to have to slip to much, cooking it and locking it up, causing loads of strain down the driveline, wearing the iRD and rear diff. The rear diff has failed first, overheated it, cooked the oil (causing the gas smell). You will need to sort the tires out, probably change the VCU and a new rear diff.

measure the diameter of the front and rear tires, if its more than 1/2 inch this will be the definate cause. what ever the outcome of this you will need a rear diff, the vcu needs checking properly and if i were you id match the front tires up anyway.

We can sort this all out or even check it over for you, but i notice you are up near Halifax so a long way for you. But do not use a so called specialist begining with "B" in the Halifax area. Cant say the name on here as last yime i did this the thread was deleted

This has turned in my worst nightmare, i thought by putting the new tyres on the back i would be ok!

This is probably going to cost us our Summer Holiday!

So its a new Diff, new VCU and 2 more tyres, i cant see much change out of a Grand!

In the mean time can i take the propshaft off? Will i be able to run it in 2wd with a hole in the rear diff? I dont want to cause anymore damage to drive shafts ect??

Thanks for the advice chaps its really appreciated!

have a look on ebay get another rear diff ,leave prop and v/c off for the time been

Ok thanks, so i cant just run it as it is in 2wd then?