Rear Differential Oil Leak on ‘03

i was wondering why my truck smelled like a skunk yesterday, and when I looked underneath I saw oil dripping from the rear diff housing. After poking around for a few minutes, and knocking off a layer of rust, it looks like there is a rust hole somewhere on the back side. This truck has resided in the northeast its entire life, and it shows. However the frame has not rusted through anywhere (yet - and it is out of warranty now).

Anyone have a quick fix, or better yet, a replacement rear diff? I would even consider a parts truck with a sound frame since I’d like to keep this one up and running for a while yet (I don’t expect the frame to last much longer).

 

Depends on the hole where and how big. Weld it up.

 

Forgot to load the pictures:

 

Holy shit! Not sure there would even be enough good metal there to weld on..

Can you at least get the fill plug out and keep the oil topped off in the meantime?

Im going to send people to these pictures next time someone says "thats a lot of rust, does not look very promising been a new Tacoma" when they see a little surface rust on a 3rd gen

 

Yeah, she's not a good looker underneath. You would have though, and expected, that the frame would have failed years ago. My dealer was not able to fail it under warranty, although they tied several times. The e-brake cable hanger in the picture has broken loose also.

It makes me laugh when owners panic over a little "surface rust", although I probably would too if I had not seen how bad it can get, and how the inside rust doesn't alway show until there is a hole.

 

I'm going to check that out now. I last checked/changed that oil about two years ago, and still have some left. I need this truck running!

 

If there is enough sound material around the rear cover, you could cut it out and weld a new cover on. From the looks of it though, you’re probably better off replacing the entire housing. I will have a non e-locker housing up for grabs in the next couple weeks, but you can probably find one a lot closer. I would feel bad condemning my axle to a future of cancerous rust anyway lol

 

This looks like an interesting option. I've got a stick welder (welds hold my skid steer together) and I recently inherited a mig welder, but have never used it.

While this rear does not have a locker, I'd love to replace it with one that does. It'd have to be an '03 or '04 with ABS though.

 

All e-locker axles are ABS ready, and most of the later non e-locker ones are too, even if the truck didn’t come with ABS.

 

This, they make em for the 8" elocker and also for the 8.4" non elocker. I have one of these covers on my 2nd gen. Instead of the factory tin foil, it's now 1/4" steel and went from 3qt capacity to a 6qt capacity.

 

That has to be the krustiest rr axle I've seen, ever. Looks like something that's been on the bottom of the ocean for decades, lol. I would be afraid of touching anything on that and it not cause worse problem. Good luck widdit.

 

Omfg, I have compassion and sympathy for you folks that live square in the middle of rust country.... That's actually sad man.
Don't know if it'd work, but possible cleaning up that rear axle enough to be certain where leak is and possibly use some of that 2 part mix epoxy stuff to plug it up? Don't even know how well that would work. That sucks dude

 

This is really cool, might be a valid option for OP

 

Looks similar to the one on my '99 when I replaced it. I also went with the Barnes cover. Word of advice- weld (or have somebody do it for you) a crossbar or a stop onto the inside of the cover where the fill plug is. They don't (or at least they didn't) have a stop in there, so you can just keep threading the plug in until it drops in to the diff if you're not paying attention.
As to enough steel to weld the new cover on, the surround on that axle housing is pretty thick, and it's load-bearing. So if you haven't broken your axle housing in half by now, you've got plenty of steel to weld the new cover to.

 

To avoid that issue, use thread tape and only go until the plug is flush, if you can. Mine gets tough when it's almost flush and thread tape creates the seal.

 

Meh. I'd still rather have a plug stop, so that I wouldn't have to worry about potentially dealing with some careless tech dropping the plug into my gears.

 

In the meantime you should try to clean it up a little and just slather on some jb weld. Thats what i did to my 4runner diff a couple months ago to stop a leak like yours and its still holding up great.

 

I scraped off most of the flaking rust, but still could not see exactly where the leak was. Checked the oil level, and it was only down about 1/2 inch. Pretty slow leak. Cleaned it up and I was going to check it after driving. Then it rained all afternoon.

The more I looked around under there, the more disappointed I became. The exhaust system is bad, including the cat connections. The rack is leaking. Rust, rust rust. I'm considering moving on, unless I were to do a frame swap on this one. Then I would be dealing with all those issues anyway. Removing any part from this truck is going to lead to complications due to rust, including any work on the rear end.

 

Ah that sucks hombre. Unfortunately it may be getting to that point. I couldn't imagine having to junk a vehicle due to rust. Crazy how Toyota likely didn't anticipate these Tacomas being in service for soooo long. Toyota HQ over there in Japan prolly laughs at the used Tacoma market here in the states

 

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