Leaking rear diff 1,350 miles after regear - install issue related? (1 Viewer)

[Zdeech]

I had my truck re-geared to 4.56 in late August last year. I followed the break-in procedure for the first 500 miles, and everything has been fine (happy with the ratio with my 3FE on 33"'s driving around +5k feet).
Anyhow, I was crawling around under rear of the truck doing a test fit on a new trailer hitch. I noticed a gear oil drip leaking out of the rear diff.

It is dry on the rear of the axle.

It looks like it is leaking at the gasket b/w the rear diff and the rear axle? I couldn't quite tell, it could also be leaking from the front of the rear diff and running down to that low point on the bottom of the axle?

I had a local gear shop do this install. I did not pull the thirds (I'm a hoping to be a some day). I provided the parts (gear package kit from justdifferentials.com).

I feel dumb for even asking this after looking under the vehicle and reading through the FSM, but this leak most likely occurred b/c of this gear installation right? My rear diff did not leak before I had it re-geared. I just wanted to run this by experienced folks on mud before I talk to the shop.

I just pulled the paperwork, and the shop warranties the work for 6 months. Under "Not Covered" it says "Leaks from the seal are not covered under warranty. As a courtesy to our customers we can occasionally replace them one time." That is kind of contradictory.

Anyhow, the leak doesn't seem bad. I am going to check the diff fluid level a bit later today to be sure it is good.

To make things more interesting, I am moving out of state in 2 weeks, and plan on driving the land cruiser 1400 miles. Currently working on prepping my house to put it on the market, and packing belongings. I want to make sure the diff is fine for this drive, and I unfortunately don't have the time to attempt to tackle this myself at this time.

 

[inkpot]

Have you tried snugging up the bolts?

 

[hammerheadfistpunch]

I had the same problem, if you didn't resnug the bolts after about 1000 miles, its very likely to seep there. My 2 cents is to ditch the paper gasket and go full RTV. Unfortunately there isn't much you can do now aside from blasting the leaky bolts with degreaser, backing off the bolts and getting some rtv in there to see if you can patch it up...or remove the 3rd member again.

BTW how are your gears? Notice any noise or lash?

 

[Zdeech]

Good call @inkpot, I will make sure they are torqued to 54 ft-lbs when I check the fluid level later today. Thanks.

 

[Zdeech]

I had the same problem, if you didn't resnug the bolts after about 1000 miles, its very likely to seep there. My 2 cents is to ditch the paper gasket and go full RTV. Unfortunately there isn't much you can do now aside from blasting the leaky bolts with degreaser, backing off the bolts and getting some rtv in there to see if you can patch it up...or remove the 3rd member again.

BTW how are your gears? Notice any noise or lash?

Sounds good, I will check the bolts.

The gears seem to be fine to me, I haven't noticed any noise or other driveline issues that I can tell. Aside from the Lokka making some noise during low speed turns.

 

[Zdeech]

I was not aware that I should have checked those bolts after 1,000 miles anyhow. Dang...

 

[Josey1972]

I have the same set up as you. Depending on where you are moving Id like to see how the gearing does at sea level. I'm planning a rear locker and am debating a re-gear while in the process. I'm not expecting it become a hot rod but Id like to get a little more out of it. Good luck with your move- and your leak.

 

[hammerheadfistpunch]

I was not aware that I should have checked those bolts after 1,000 miles anyhow. Dang...

Me either, but then again, the shop that did the regear told me there was no break in for gears and later, when I was forced to redo their work, I found they had used the rear carrier bearings in the front. Good times.

 

[Zdeech]

I have the same set up as you. Depending on where you are moving Id like to see how the gearing does at sea level. I'm planning a rear locker and am debating a re-gear while in the process. I'm not expecting it become a hot rod but Id like to get a little more out of it. Good luck with your move- and your leak.

As luck would have it, I am moving to 50' above sea level (Portland, OR). Send me a message in a few weeks and I will let you know what I think.
I had 30" diameter tires on this truck when I first bought it. A friend with a '92 LC drove it and noticed the performance was better than his stock 4.11 with 33"s. It looked ridic with the 30" tires though. I then lifted it, had 33"s installed, and put on a roof rack, and at that point the performance really sucked. Especially on the highway. 4.56's have been perfect for me, it basically returned the gear ratio to stock. In my opinion, 4.88's with 33"s would be not tall enough. It would really be screaming on the highway. People do say though if you plan on ever going to 35"s, you should go with 4.88s.

 

[Zdeech]

Me either, but then again, the shop that did the regear told me there was no break in for gears and later, when I was forced to redo their work, I found they had used the rear carrier bearings in the front. Good times.

Geeze man, that really stinks. Wow, that would have taken a while to shake that off...

 

[Malleus]

Sounds good, I will check the bolts.

The gears seem to be fine to me, I haven't noticed any noise or other driveline issues that I can tell. Aside from the Lokka making some noise during low speed turns.

Be aware that if you're planning to check the installation torque, you have to loosen the bolts and retighten them to do it. You will not get a good reading on the bolts if they're already tight. (Static vs. Dynamic Torque, 'natch)

My bet is the joint is not closed due to improperly loaded bolts. Get the bolts tight, check it for leaks the next two or three weeks, and let EVERYONE in your area know the name of that shop.

 

[Zdeech]

Be aware that if you're planning to check the installation torque, you have to loosen the bolts and retighten them to do it. You will not get a good reading on the bolts if they're already tight. (Static vs. Dynamic Torque, 'natch)

My bet is the joint is not closed due to improperly loaded bolts. Get the bolts tight, check it for leaks the next two or three weeks, and let EVERYONE in your area know the name of that shop.

Oh okay. I just checked the fluid level, and it is about 1/4" lower than the fill hole. This is after 833 miles / 4.25 months.

I checked the torque on the bolts, and they were at 34 ft-lbs. That was the spec I found later in the FSM, although the image I loaded earlier made it look like the torque should be 54 ft-lbs. I DID NOT loosen them first, so I will go back and do that, and get some gear oil to top it back up. Thanks for the tip.

So, how would you folks proceed? Should I go back to that shop to have them look at it? I am hesitating to go back there now. Just loosen and re-torque and see what happens? When I was back down there it actually looked like the leak might be coming from the front of the rear diff where it meets the propellar shaft.

 

[hammerheadfistpunch]

Oh okay. I just checked the fluid level, and it is about 1/4" lower than the fill hole. This is after 833 miles / 4.25 months.

I checked the torque on the bolts, and they were at 34 ft-lbs. That was the spec I found later in the FSM, although the image I loaded earlier made it look like the torque should be 54 ft-lbs. I DID NOT loosen them first, so I will go back and do that, and get some gear oil to top it back up. Thanks for the tip.

So, how would you folks proceed? Should I go back to that shop to have them look at it? I am hesitating to go back there now. Just loosen and re-torque and see what happens? When I was back down there it actually looked like the leak might be coming from the front of the rear diff where it meets the propellar shaft.

If its leaking from the pinion seal, absolutely make them go back in and check it. Mine was also leaking from the pinion seal because they used a 100 series pinion but an 80 series seal (Nitro didn't have the right spline count pinion for my 80 at the time so the 100 pinion is an acceptable substitute...if you use the right seal.)

 

[Malleus]

If its leaking from the pinion seal, absolutely make them go back in and check it. Mine was also leaking from the pinion seal because they used a 100 series pinion but an 80 series seal (Nitro didn't have the right spline count pinion for my 80 at the time so the 100 pinion is an acceptable substitute...if you use the right seal.)

x2 - if they won't honor a leaky joint, OK. I be PO'd but I could live with it. I wouldn't go back, but I could choke it down.

If it's the front seal though, that's too much to ignore, especially since you paid for it. It would give me reason to suspect the quality of the entire build. It's not like your neighbor did the job for beer, after all (it's not your neighbor, right?).

 

[Notch]

I would bring it back and have them fix it. If I sent something out and it started leaking shortly after, I would fix it no questions asked. Most transmission shops will fix leaks after a rebuild for free too.

 

[I Lean]

It's not unheard of to have a pinion seal leak right out of the box sometimes. Rare, but it happens. More likely is leaks through the pinion splines if they didn't seal that area when installing the flange. Take pics of the front end of the third for us?

 

[Zdeech]

I went by the shop that did the work yesterday, and the owner determined it was leaking at the pinion seal. He advised me on what parts to get, and will do the repair at no cost anytime next week. I went to the local dealer, and they had the pinion seal in stock - part no. 90311-38047.

I also ordered part number 41204-60050, the flange, sub assembly. It should be at my dealer by Tuesday.
Shown here:
4120460050 Genuine Toyota FLANGE SUB-ASSY 41204-60050

As a side note, my local dealer, American Toyota in Albuquerque, is where CDan worked. They are still honoring the ih8mud discount of 20%, I have been working with a parts guy there named Don since last Spring, and he is very helpful.

Anyhow, I figure this could fall into the $&*! happens category. The shop has a good reputation locally, and they were friendly and helpful when I dropped by yesterday.

I really appreciate everyone's input on this. Thanks for your time. After thinking about it for a minute, I just upgraded my account to a silver star for a year, just pending payment approval.

Thanks,

Zach

 

[Zdeech]

x2 - if they won't honor a leaky joint, OK. I be PO'd but I could live with it. I wouldn't go back, but I could choke it down.

If it's the front seal though, that's too much to ignore, especially since you paid for it. It would give me reason to suspect the quality of the entire build. It's not like your neighbor did the job for beer, after all (it's not your neighbor, right?).

Ha ha, no sir, it was not my neighbor. Unfortunately, I do not currently live close to any gear heads. My neighbors are the type that are impressed if they see you do an oil change.