Our '95 SR is down because the rear diff fluid is leaking out through a weld crack. The weld on driver's side axle tube extension off of the differential is cracked about a third of the way around. It started as an annoying mysterious drip and now is an official leak.

We removed the axle with the intention of welding it up. We cleaned it up ground a bevel into it, removed the axle shaft and then chickened out due to listening to dooms dayers.

I have production weld experience but I don't know the metallurgy of the axle. It appears to be cast steel so with a little preheat it should be able to be welded without exotic welding requirement. But, I would feel a lot better if I knew that others have welded their axles with success and how they did it.

Thanks for any advice/experiences/knowledge/sympathy. I will add pictures this weekend.

I have never heard of one of these (Gen 2, SR, specifically) getting a crack in one of the tubes. Can you patch it or does it seem like it's affecting structural integrity? I would think the latter, unfortunately.

I'd say you have little to lose, so go for it.

I saw some comments on Facebook this morning that it was snowing lightly in Peoria. Ha ha, it's 90 here today...

John B.

For all the work- why not just swap a different housing? Seems like if that one cracked, it might have been defective from the get go. It shouldn't be too difficult to find one that you could swap in. If you do a lot of wheeling you could even swap one in that has the air locker.

If it lasted this long before cracking, I would assume its not totally defective. Maybe weld it up and then weld bracing across the seam?

Let me tell you all something about central Illinois, where the OP is at. He probably has one of two in a 100 mile radius. NO ONE drives something like that back there.

John B.

He's got a 95 SR, it's already equipped with the air locker.

Frankly I'm amazed that the housing is cracked - I've never heard of anyone having issues with that before, and there are a lot of people on here that beat the living crap out of their Monteros, myself included. If you've got the capabilities to weld it, by all means do it. Welding an axle housing is nothing new, and these housings are pretty darn stout to begin with. If you can clean it up thoroughly I don't any reason that you shouldn't be able to repair it permanently.

I've only heard of it one other time (due to rust)

You're good dude, that whole housing is stamped steel. only the 3rd is cast. Sweat it and use 7018 or 71M, L56 will work as well but i prefer the first two for strength.

This happens on Gen 1s used off-road on a regular basis, but this is the first time I have heard of a Gen II. My experience has been just like welding broken trailing ARMs, it does not seam to last.

It doesn't happen in N. America very often but I've heard of it happening in Australia. Maybe check on their forums regarding welding metallurgy and known best fixes.

Well, it is a little chilly here but the leaves are gorgeous. Do you remember what leaves are JohnnyB? Yah I know, I'll have to rake them soon but I won't be sweating walking to the shed to find the rake.
Anyway... we took the axle too the local community college last night, one my pals is a dealer tech trainer for the largest earthmoving company in the world.
He took a look at it and said that we could weld it up "No Problem".
So, my buddy wheels over the hoist sets it up on jack stands and begins grinding it clean. When we had it all cleaned up we found the crack followed the parting lines and that it was most likely an incomplete initial weld. We of course discussed it for a while and came to the conclusion that the robot welder used to weld it initially was off registration - both welds, the left and the right were similarly biased so the edge of the part was not hit with the weld on both, the left a little worse that the right.
Well he welded it up, wish I would have done the welding myself actually, and we should be back in business. We tested the new weld and found no signs of porosity - no leaks. The other weld we left alone (don't fix it if it ain't broke philosophy).
One interesting thing that you might be interested in, my buddy before welding it, got a tank of nitrogen out and put the hose into the drain plug on the diff and turned it on just enough to feel it come out of the tube end. He said this is common practice when working on the big stuff. What it does is stops any oil inside from catching on fire, as well as help to keep any rubber or plastic cool while welding (seals). He said that you could use CO2 as well.
As for pictures, I asked my son for his pictures of the crack, he said "uhhhhh", well if we find any I will post them. When I get home tonight I will take some of the fix.
Well, I guess I'd best get going, I have to find my ice skate <img src="/forums/images/graemlins/lol.gif" alt="" />
P.S. Thanks for all of the feedback. You guys(that's male and female) are great. Happy wheelin