axle seals leaking after seal replacement

Hey Tacoma junkies!
Background: I took my Tacoma in for the rear diff seal about 3 mo ago and when they did the work they didn’t replace the rear axle seals. They started to seep on both sides immediately. Got the warranty work for that and now the drivers side is seeping again about two months later.
Q: Is this a common issue with anyone else on this forum? There are some attached photos of the drivers(seeping) and passenger(no seepage). I’m wondering if it’s the techs doing the work.. Or did I just get a crappy finished rear diff and hub assembly from the MFG? No matter how many seals you throw at it there might be damage or warped metal contact surfaces.

 

Bring it again again. Maybe this time they’ll replace the whole unit

 

That was what I was thinking also. I will recommend it as a solution to the consistent issue. Appointment this next Thursday.

 

Is the axle vent clogged or pinched off or anything? Usually this is the reason axle seals go. Pressure builds in the axle blowing the seals out. I've been victim to this a couple of times. Toyota's little check valve on the axle housing is effective...but only if it never gets dirty or damaged.

 

ugh, yeah take her back in.
I would nicely inform them, that you WILL BE cleaning off the area, checking often. Does the work carry a warranty further or outside Toyota's warranty? Might be something you ask them, as they will know, that you understand who will be on the hook for the bill, should it leak again. I would not think Toyota is NOT reimbursing the dealer for rework, unless they can prove the assembly is out of spec and will never seal.

 

I checked the valve and it’s moving freely. They said they checked it for function and it was working also. I do live down a 300ft long gravel road so I wonder if the dust is getting trapped. I drive slow enough where it doesn’t kick up dust most the time. My roommate also has a 2016 and they don’t have any issues. All my other driving is on road.

 

The whole vent is just threaded into the axle housing. If memory serves correctly, it is just a pipe thread fitting (BSPT or the metric equivalent name) You can get an appropriate size socket\wrench and remove it to make sure there is no dirt or anything in it. Blowing pressurized air up through the valve (same direction as it would when it's installed and doing its job) to be sure it is clear. After all, it really is just a spring and ball check valve. Not too complicated of a design, but worth a slightly deeper check for peace-of-mind.

 

It’s literally only been 2 weeks since it started to seep. I check twice a month now alongside when I check my fluids, entire engine bay and suspension. I think that might be the route they go if I hit the 3rd time at the dealer for this issue. Hopefully they decide to pull the trigger with a new differential housing if the work isn’t enough. If not, then it’s lemon law buy back time which I do not want to have to do.

 

They most likely nicked the seal when they were putting the shaft back in the axle housing. Hard to tell when you are doing it so it was most likely an honest mistake. Just take it in for your appt and let them fix the issue.

 

That’s the plan. I’ve been to this dealer like 8 times now haha they love me. A good review and some house plants as gifts wins them over.

 

Seal they replaced was rear diff pinion seal I assume. That seepage is really very minor and may stop but try the stuff below. Bad is running down the backing plate on the wheel and spraying/flinging all over ha ha.
On gen2 should be same as your gen3 there is an O-ring between the axle tube and 4 mounting bolts/nuts and they don't always tighten them on the lowers too well. One has the shock mount in the way so use a box end wrench and see if its tight. Even a few drops of gear oil that drip down looks like alot so spray it all down with brake cleaner and then see.
Did you pull the upper rear diff fill plug and see if any gear oil came out indicating it was over filled? Or wait for the dealer again and tell them to change that breather vent too. All the auto parts stores sell them and many of us change them out for a 2 way breather remoted up in the taillight or bed to avoid clogging and a hot rear sucking water in stream crossings.
As for the lemon law do not hold your breath on that approach - they can out last and out BS you for alonggggg time. As for the national Toyota assistance # do not waste your time they are clueless and take forever to do nothing.

 

Right this was extra work that had to be performed from the rear diff third member gasket seeping issue. I was reading somewhere online in a service manual that it is recommended to replace the rear axle seals when doing any sort of work that requires removal of the axles from the third member. Is this Toyotas way of getting around the books by sliding them out only 3”? My guess is yes.
And Trust me I do not want to do the lemon law because this truck is my favorite so far with the manual 6 speed. I have it tuned perfectly right now as well and I have pretty much babied this thing with fluid changes.
You definitely have a point about the overfilling part. Blowing the seals or allowing the fluid to push past from the pressure increase and clogged vent. Are all the differential housings the same size across all the trim levels? Toyota uses different fill capacities based on the equipment. They should just come up with one fill level and design it around that and save people hassle.
My friends off road has the same rear diff housing as mine. Except his has the electronic control since it’s an off road. Other than that the only real difference is the different third member gear ratio. I don’t understand why Toyota even uses different fluid amounts Since they’re the same housing. If the dealer filled to the line and that’s the case then it’s overfilled. But if they added the correct amount and it filled to the top and started to drip then that’s fine. I think the manuals call close to max fill on these. They need to do something about this breather valve then if it keeps popping up. Here’s a screen shot of the fluid levels based on equipment. 3.8l for the manual. Which is just below the max fill. If they filled it to the top, which is probably the 4.0l then it’s overfilled by 0.2liters. They wouldn’t make a differential that holds more past the fill plug.

 

I had a repeat leak at the left rear that took me a couple tries to figure it out. At the outer end of the axle just inboard of the bearing there is a few spacers stacked up. One is the tone ring for the abs sensor, a spacer and a sleeve that the lip of the seal rides on. On mine the lip of the seal was resting right in between the spacer and sleeve where they meet, down in a small channel. I found it by painting blue silicone caliper grease on the spacer, installing the axle and then removing it to see how far the seal rubbed the grease off. So I had 2 choices, I could reposition the sleeves and spacers or I could reposition the seal. I didn't want to push the abs ring around so I opted to reposition the seal. Got another seal and tapped it in with my installer tool, stopping a fair distance short of the old one. Still plenty pushed in so it wouldn't pop out, but not fully buried down in the axle tube. Checked again with caliper grease and the lip was now fully on the sleeve, not in the groove. No more leak since

But realistically, if they had the axles out they should have replaced the seals. They may have knicked one putting the axles back in. And yes check the vent

 

The dealer is saying that the leaking is from residual brake fluid when they changed the seals last. Funny thing is that only one side is leaking And I’m pretty sure they cleaned up the area after working. It was dry when I looked after getting the vehicle returned. I gave my service rep permission to take the vehicle home tonight to see if it will seep any more after they cleaned it. Are they even allowed to do that? It will be driven 50ish miles when they check it next. I will see if the truck is actually still at the dealer tonight. They also said that they washed the brake fluid off with water. I doubt it and I know that it’s diff fluid since it’s only seeping out from the sealed bolt area.

 

It’s not uncommon to take problem children home, to put miles on them, to attempt to duplicate the issue.

 

They cleaned it off a few weeks back at the dealer thinking it was just residual from bleeding the brakes. 3 weeks later and it’s Seeping again. I’m taking it back in next thurs. They took pictures and said if it seeps again (for like the 4th time) bring it back and they’ll replace it. Just the drivers side rear. Keep y’all updated on what they say.

 

Drivers side

 

They don't know the difference between brake fluid and gear oil? That's something I would be concerned with...

 

This is unfortunately a common process of elimination that dealers do I feel like. They are liable for the repair so they are taking precautionary measures probably. He came up with an excuse that the brakes were only bled on the drivers side and that’s why there’s residual oil. And that they could spray it off with water. Biggest turd I’ve ever heard come out of someone’s mouth.

 

If seals aren't tapped in evenly they will be junk. Easy mistake because it's hard to tell sometimes.
Not doubting the mechanic. Shit happens.