It was inevitable - rear axle diff cover now leaking.

I replaced my rear diff housing just over a couple of years ago and I knew at the time that the axle itself was on borrowed time give how the back cover was just so rusted. But I got another 2 years out of it before it started to leak.

I know I can do the swap but I need to find an axle first. I did a quick search and it looks like they aren't even in stock anymore on OEM sites, so I'm wondering is there a reliable place to still find these axles?

I've got a 2001 4.8L 4x4 SR5 Access Cab , all stock.

 

you’re gonna have to come down south and source one out of a junk yard. That would be the bestest route but I know travel is one of those “eehhhhh” kinda things for people.

but junk yards or trying to find a totaled truck of some sorts.

 

Depending on where it's leaking, is it not possible just to have a shop cut off the OEM welded cover and weld on a new Dorman part?

 

Is the frame worth the investment? If so, when looking and ordering a new or used rear axle assembly, make sure you match the gear ratio properly so it will match with your front differential.

 

car-part.com for wreckers.

 

Thinking of going this route, I'll see if I can find someone who can do the welding. I think it's leaking from the bottom of the pan, not the axle itself.

I think I also saw someone on this forum that may have done a custom bolt on with a Dorman as well.

 

Yea the frame is good. I've no idea what gear ratio I have, how would I find that out?

 

Might be part of the VIN as I’ve seen others here look up the original options that way. The standard ratio would be in the owners manual.

 

Your rear diff is 3.91, and some pics would be great for the crowd here to assess what your dealing with.

 

Divide the number of teeth on the ring gear by the number of teeth on the pinion gear and you'll arrive at your gear ratio. If you are certain nobody has ever tampered with it since it left the factory, you might be able to do it through the VIN as well.

 

I've got an appointment Friday with my shop. He seemed hesitent until he has seen what needs to be done, as they've not done one before it sounds like.

Just to put his mind at ease, does the differential itself need to be removed to do this, or can it just be jacked up and the old one cut off?

 

We need pictures

 

Here are some photos. The first one shows the new diff housing I put on 2 years ago.

 

I have found a couple of places to get the axle housing, but it's not cheap. Cheaper than a new truck though!

This is the part number for the 4x4 without ABS - Axle Housing - Toyota (42110-34141)

https://www.autopartsprime.com/toyo...year=2001&submodel=&extra1=&extra2=&filter=()

 

So now you're concerned about the leak around the drain plug, or are you wanting to replace the axle housing? Seems to me that you have a salvageable housing there and might just need to give it a thorough cleaning up. Kinda hard to go by picture. As for the plug leaking, if you clean up both sealing surfaces nicely and put on a new crush washer/seal it should seal.

 

It's not leaking from the plug as best I can tell, it's leaking from the bottom of the pan under all the chunks of metal that are flaking off.

Yes the axle housing is in good shape, I'm pursuing just having someone cut off the pan as of now, but if I can't make that work out I'll just get the whole axle.

 

Might want to clean the scale off. Then clean any oil residue off with some solvent so you can determine where the leak is. Looks like it is leaking at the drain plug hole and the scale is wicking up the oil leading you to believe that it is leaking from a pin hole in the housing. With some aggressive scale removal, you might get lucky and save over a grand.

 

I'll give it a shot. I'm inclined to think it's not the plug though, because the drip point is higher than the plug itself. You can see it in the 3rd photo. If the plug was leaking, it'd drip from the plug.

 

The question is are either of us 100% sure at this point? I see your picture and understand gravity, but I also know wicking oil is a thing too. Think oil lamp for a moment. Intermolecular forces create capillary action and oil is drawn up the wick.

 

The cheap, not-permanent but good enough for the girls we date method:

If you have Ramps back it up on them, gives you more room to work. Then go to town on that with degreaser and a stiff brush. Clean it off real good then take a spin down the block and back. Your leak point will be obvious. Clean it off with brake clean, jb weld over the spot, top off on gear oil.

you’ll be chasing another pinhole in a month or two this way if yours is as rusted as mine, but it works good enough to keep you rolling.

Also highly recommend removing the breather valve at the top and replacing with a new one, or at least cleaning yours real good. They seem to gunk up and fail, builds excess pressure inside and will create more pinholes

 

Any pictures of where you made patches? Might be something that would help to determine if there is a common spot where they typically develop a leak.

 

Drive shaft failure/Mechanics Special 05DC Refresh

Post 94. Scroll back a page for cleaned pics of the housing. My pinholes were above the fill bolt. Honestly these trucks are just rust buckets though, I doubt there’s one specific place. Just go out there and clean it, should be obvious after a short drive

 

Is there a reason this wouldn't fit my 2001 4x4 SR5? For some reason both Amazon and Dorman's site is saying it isn't compatible.

$63 Dorman 926-958 Rear Differential Cover Compatible with Select Toyota Models (OE FIX)

https://www.amazon.com/Dorman-926-9...33------------&vehicleName=2001+Toyota+Tundra

 

If I change it to 'RWD' from '4WD' then it says it's compatible. I didn't even know that Toyota made a RWD only Tundra?

 

All of the people that used it to fix their rear diff also found it not compatible. Then they installed it. And like magic, it worked. Fucking amazing.

Oh wait, let me use that magic thing called search.

https://www.tundras.com/threads/rear-diff-cover-replacement.119008/

https://www.tundras.com/threads/rusted-leaking-rear-differential-cover.27684/page-3

I'm almost tempted to believe ... it works! Kinda like the search feature, most of the time. Holy shit!

 

Yea I think Amazon is basing it on Dorman's site which only lists a few variants.

I had my regular shop look at it and he's not super confident in estimating the cost because he's never done something like this. Worst case is that it'll be 15 hours of work and he'll bill me 130 for every hour.

I stopped at another shop with a pretty good rep and was much happier with their take on it. He said worst case wouldn't go over 1000 bucks and it'll likely be a few hundred. They've done a lot of diff covers, but never a welded one. They've done lots of weld jobs though.

Of couse if this ends up costing me near a thousand bucks, I'd rather just get the axle and do it myself. Is this cover job pretty reliable long term if installed well?

I'm also wondering how long the actual axle lasts. Mine seems good, no chunks flaking off like the carrier housing was and the diff cover now.

 

What’s your state

 

Napa has a nice page with an overview of the process.

https://knowhow.napaonline.com/how-to-replace-a-toyota-diff-cover/

I can't imagine any way of doing this right with the diff on the truck, and certainly not the gears in place.

An option between JB Weld and a complete cover replacement is weld on small steel patches on the perforated area(s), assuming there's enough good steel left to weld. I can't find a picture right now, so just use your inagination