O.T. Toyota truck rear differential leak

Sorry for the O.T. post!

I have a 1994 Toyota 4x4 4-cyl. regular pick-up truck (not a Tacoma, not extended cab, etc.) The other day I noticed a puddle of gear oil under the rear differential. When I checked, what looks like the back cover of the diff. rusted right through and started leaking (small pinhole or crack somewhere). You can peel the metal right off in chunks.

Apparently, the Toyota axle does not let you simply pull the cap and replace it; it"s part of the axle and the whole axle needs to be replaced. Brand-new, it"s $1400, not worth for a 1994 truck. I can get one second-hand but it would have to be in fairly good shape to be worthwhile.

A mechanic friend of mine suggested welding a patch onto the rear "cover". I don"t weld but I have a neighbor who is a professional welder; he"s done lots of welding on my tractors and farm implements.

What do you think? Which route should I take? And if he does weld a patch, will I need to pull the fuel tank off? (done it twice already, a major pain in the ...)

Thanks in advance for your help. I definitely don"t want to junk the truck over this; it"s only got 157,000 miles on it.

I'm GUESSING the axle is made with a drop-out "third member" like the classic 9" Ford, so the back cover is a welded-on part.

It should be NO problem for an experienced weldor to patch it.

Since there's oil/petroleum vapor inside the axle there's always a chance of that lighting off from the welding. An experienced weldor will know how to deal with that... take it apart, vent it with a flow of air, or fill it with an inert gas.

He can also assess the risk of the gas tank.

I"d go either way, get it repaired or go to a junkyard and get a replacement. I was at the local pull-a-part the other day and saw several of them. Check the play in it, check the fluid in it. When you put it in your truck change the brakes and the wheel bearings. I"ll bet you could be into a replacement differential for about $200 from a place like that.

"I"ll bet you could be into a replacement differential for about $200 from a place like that."

Yeah, plus HOURS of aggravation getting the "U" bolts loose and swapping the other axle in AND breaking brake lines trying to loosen them AND messing around bleeding the brakes AND AND AND, vs a few bucks to patch the old cover!

If you got a buddy that will weld a patch on,go for it.
Another option is JB Weld and screen wire.Layer of JB,lay screen wire in,cover with more JB. Works Great!

Might consider going to NAPA and get a gas tank repair kit with fiber glass cloth. I patched a hydraulic tank with it.

Another option is JB Weld and screen wire.Layer of JB,lay screen wire in,cover with more JB. Works Great![/quote]

That's the answer right there. Just make sure it is clean and rough it up some.

Is your truck included in the frame rust out buy-back program? I know a guy who is getting his bought back soon, so I wondered. Supposed to be good money that they give for them.
Zach