Differential issue

my ‘05 double cab has had the left rear axle seal replaced twice since it was wrecked about a year ago. My mechanic says that it’s because the differential is slightly bent and needs to be replaced. I heard him tell the adjuster this when the wreck happened and the adjuster disagreed with him. New differential is $3,500 and other than the gear oil leaking at the axle seal I haven’t had any issues with driving. Anyone else ever deal with anything like this?

 

The axle lube can potentially contaminate your brakes. See if you can get a junkyard housing or complete rear end.

 

Would a complete rear end be better or cheaper than just replacing the differential?

 

Never mind, I asked the mechanic and he said the $3,500 is the installed price for a whole new rear end from a junkyard.

 

That seems awfully steep for a junkyard rear end. Car-part.com has them for under $1500 and it shouldn't be more than a couple hours labor to install.

 

I'd check the breather first.

 

Got any pics?

 

Always good to think of the simple things like this first! So obvious but I skipped right over it. I guess I just assumed the mechanic is correct. But it could totally be the breather. It could just be the axle and not the housing as well. It would be nice to check the run out on that too if a new breather doesn’t work.

 

Thanks for the suggestion. This problem is the result of the truck getting hit from the side right at the axle on the highway. I honestly have never heard of a breather before but I trust my mechanic’s diagnosis. He spent a long time going over it and he’s worked on all my cars for the last 20 years and he comes to me for all his HVAC problems.

 

I'm not putting down your mechanic but it's possible he may not be aware that the breathers on these trucks are known to rust shut over time.

 

Gotcha, thanks. I’ll definitely bring that up to him.

 

Super cheap to try. And even if it isn’t it I would want a new breather on the junkyard reared as well.

 

It’s easy to confirm if the breather is working. Just unscrew it off of the top of the differential and blow through it.

 

I’m betting he pressed the “retaining ring” and ABS tone wheel onto the axle shaft until they bottomed against the snap-ring. I know I did the first time I did a first gen. rear wheel bearing / seal, and I had a repeat leak that was worse than before.

Here’s a diagram showing how far to press it all together:

 

I actually talked to him about this when the axle seal leak came back the first time. He said he’s worked on a lot of 1st gens and has a guidebook for the repair that included this.

 

Well good thing I didn’t bet any more than my internet dignity on that one.

 

Have you contacted your insurance to have the original claim reopened or added to?

This shouldn’t be your bill out of pocket.

 

Yeah, my mechanic is contacting them to try to make them cover it since he told them about it when he did the original repair.

 

You mean like this?

 

Do you mean the axle housing is bent or maybe the axle? The axle seal is almost three feet away from the differential. A bent differential is not something I have heard of before. I would get another opinion, even though you say you trust him. Sounds like BS to me.

 

I can’t measure from here, but I’d say those are pressed on too far.

 

Pretty sure he means the axle housing. Otherwise it should just be a replacement of an axle shaft.

 

I think they are just from looking at the shiny part. But it's not leaking so idk.

 

I figured that, just trying to picture how an axle housing would be bent enough to cause an axle seal leak without any other issues. Pictures of the carnage would be nice, maybe some alignment readings as well.

 

Any vibration while on the xway?

If no, I'm betting nothing is bent. Axle seals are a known weak link .

 

My axles seals failed due to a stuck breather. The diff oil contaminated the drums shoes and those had to be replaced. Replace your breather with a new one and extend it up to behind your gas tank cap or rear brake light area.

 

He kept using the word differential but I don’t know. He said the issue is something being bent (very slightly but still visibly) that is making the axle not spin perfectly straight which is in turn keeping the axle seal from working properly. He said the leak isn’t catastrophic but you can see the fluid leak. He said he pointed it out to the insurance adjuster last year and the guy just said “nah that looks fine” and only approved the axle seal. He replaced the axle seal under warranty once and now it’s back again and he says the truck needs a new rear end. There are no vibrations on the highway. I guess I’ll fins out more when I meet the insurance adjuster at the mechanic’s this week.