rear differential fluid leak?

[tcpoob]

punch flange nut after torquing it down

What do you mean by "punch the flange nut after torqued it down"? Once it's torqued down per FSM, it (the large bolt Justin mentioned?) still needs to be "punch"ed?

making sure i understand the process to get to pinion seal, not that I'll do this myself:
1. disconnect drive shaft from flange by removing 4 bolts and nuts
2. detach flange from pinion by removing the large bolt

Thanks for all your time.

I would use a torque wrench and go with the new bearing specs from the FSM. I wouldn't aim for exactly where it is sitting now, because it might have backed off or not being torqued correctly from the repair and that is why it's leaking.
I wonder if dude forgot to punch the flange nut after he torqued it down. Mistakes happen.
I am a bit confused on why he wanted you to come back after 200 miles though. Unless that was a bs reason to not warranty his work.

 

[notrayray]

What do you mean by "punch the flange nut after torqued it down"? Once it's torqued down per FSM, it (the large bolt Justin mentioned?) still needs to be "punch"ed?

Yes, just like this....

 

[notrayray]

Here are some more pics....I think this is an older 8" Toyota diff but it's exactly the same.
Toyota Pinion Seal Replacement

 

[tcpoob]

punch!

Thanks. So a new large nut is used every time, which gets punched into the "key" on the bolt after torqued down? this is too advanced for me. I mean, how do you unscrew that large nut after it's punched into the bolt?

I'll fill the rear diff tomorrow and if the repair will require draining rear diff, maybe i don't need to add the fancy Mobil 1 Supersyn 75W90.

 

[notrayray]

Thanks. So a new large nut is used every time, which gets punched into the "key" on the bolt after torqued down? this is too advanced for me. I mean, how do you unscrew that large nut after it's punched into the bolt?

I'll fill the rear diff tomorrow and if the repair will require draining rear diff, maybe i don't need to add the fancy Mobil 1 Supersyn 75W90.

You have to unpunch it, as it were. A thin, small cold chisel works good.

No need to drain the fluid for the repair.
:cheers:

 

[Justinlhc]

I would use a torque wrench and go with the new bearing specs from the FSM. I wouldn't aim for exactly where it is sitting now, because it might have backed off or not being torqued correctly from the repair and that is why it's leaking.
I wonder if dude forgot to punch the flange nut after he torqued it down. Mistakes happen.
I am a bit confused on why he wanted you to come back after 200 miles though. Unless that was a bs reason to not warranty his work.

Good point. :thumb3:

I'm guessing the 200 mile thing was just an excuse to cover up his crappy work so he didn't have to honor it and fix it for free. I'd give him hell at the very least. It certainly wouldn't hold up in court.

 

[tcpoob]

Good point. :thumb3:

I'm guessing the 200 mile thing was just an excuse to cover up his crappy work so he didn't have to honor it and fix it for free. I'd give him hell at the very least. It certainly wouldn't hold up in court.

thanks for the suggestion, i'll discuss it with him when i bring the ride in, armed with your expert advices. so thankful for you all spending precious weekend time giving tips - they call it hobby, do what u like and you don't work a single day!

 

[tcpoob]

You have to unpunch it, as it were. A thin, small cold chisel works good.

No need to drain the fluid for the repair.
:cheers:

Cool,:thumb3: Now i feel better refilling some Mobil 1 lube in there.

I am guessing the leak might have started weeks ago until I got serious about it last Thu night, since it's always under the diff. Which means it started a couple months later since the repair job. Can the mechanic argue that it's not from his work as it'd been several months long? I am thinking if he didn't torque it right, or didn't use a new pinion seal, or didn't "punch" it, this could happen, right - it slowly loosened up and started the leak?

Thank a lot.

 

[notrayray]

Cool,:thumb3: Now i feel better refilling some Mobil 1 lube in there.

I am guessing the leak might have started weeks ago until I got serious about it last Thu night, since it's always under the diff. Which means it started a couple months later since the repair job. Can the mechanic argue that it's not from his work as it'd been several months long? I am thinking if he didn't torque it right, or didn't use a new pinion seal, or didn't "punch" it, this could happen, right - it slowly loosened up and started the leak?

Thank a lot.

Did he ever say what you were supposed to come back for after 200 miles?

IMO if he doesn't warranty it, it should be the last time you use his services.
In his defense, he doesn't know what you have been doing to your vehicle for the last two months.

I think I would get under the rig with a flashlight and see if the nut was staked (you should be able to see it without taking off the driveline) If not, you have your answer and some ammo to take to your mechanic.

 

[swise]

awww ****!
that sucks.
definitely pinion seal install goof. Hopefully this "mechanic" will not give you problems with doing the rework
700.00 just for labor on a diff. bearing R+R??

 

[tcpoob]

awww ****!
that sucks.
definitely pinion seal install goof. Hopefully this "mechanic" will not give you problems with doing the rework
700.00 just for labor on a diff. bearing R+R??

yeah, that includes the labor for replace a few bearings in the rear diff, change engine oil (oil provided by me), change all 3 diff fluids (lube provided by me), change rear axle brake rotor and pads ( rotor and pads provided by me).

 

[tcpoob]

checked fluid

i don't know where to look for and check the rear diff breather to tell if it's clogged - where is that thing? is it a hole, a hose?

i finally opened the rear diff filler plug and checked fluid. my estimate is it's about 1 cm below the bottom of filler plug. so there are still some gear oil left to get to the repair shop and work tomorrow 50 miles away.

in terms of the axle nut (30mm?), i couldn't see it when under the truck. i am guessing the shaft would have to be taken off to reveal axle nut, right? are those four shaft nuts/bolts easy to take off? Once taken off, wouldn't I need to support the shaft somehow? is it really heavy - the shaft?

Thanks.

 

[notrayray]

i don't know where to look for and check the rear diff breather to tell if it's clogged - where is that thing? is it a hole, a hose?

i finally opened the rear diff filler plug and checked fluid. my estimate is it's about 1 cm below the bottom of filler plug. so there are still some gear oil left to get to the repair shop and work tomorrow 50 miles away.

in terms of the axle nut (30mm?), i couldn't see it when under the truck. i am guessing the shaft would have to be taken off to reveal axle nut, right? are those four shaft nuts/bolts easy to take off? Once taken off, wouldn't I need to support the shaft somehow? is it really heavy - the shaft?

Thanks.

Hard to tell but the circled portion looks like it........should be in that general area.

Hopefully, you topped off the rear diff before you left, it should be no more than 5 mm from the bottom of the fill plug.

Those four nuts/bolts are what hold the axle shaft into the diff. You undo the e brake cable and the hard line at the brakes, unbolt those four nuts and pull the entire assembly out of the axle housing....

It would look similar to this but you probably have disc brakes and you have ABS which will have another toner ring on the axle shaft....


Weighs about 35-40 lb's.

Though, the axle shafts don't have to come out of the differential to replace the pinion seal.

 

[tcpoob]

i called the mechanic and he said it's too wet today to troubleshoot the leak so waiting till another day.

the picture you attached look more like the rear axle going to a wheel than the drive shaft connecting to rear diff to my very uneducated eyes.

 

[notrayray]

i called the mechanic and he said it's too wet today to troubleshoot the leak so waiting till another day.

the picture you attached look more like the rear axle going to a wheel than the drive shaft connecting to rear diff to my very uneducated eyes.

You said axle nut, and I ran with it.

 

[tcpoob]

my bad, i didn't know better and likely misused the term - i probably meant "pinion nut". It's the 30mm nut that needs stake/unstake.

i read up on diff breather in the forum and will take a look at mine to see if it's clogged. Do I have to locate it, remove it to inspect it or can I determine if it's clogged without removing it? I think someone said it's 14mm. Just watch out for hissing pressure gas relieve?

You said axle nut, and I ran with it.

 

[notrayray]

my bad, i didn't know better and likely misused the term - i probably meant "pinion nut". It's the 30mm nut that needs stake/unstake.

i read up on diff breather in the forum and will take a look at mine to see if it's clogged. Do I have to locate it, remove it to inspect it or can I determine if it's clogged without removing it? I think someone said it's 14mm. Just watch out for hissing pressure gas relieve?

I was wondering, thought you were maybe having at the repair.

The stock breather is the one on the left...


twist it to knock excess dirt loose, then you can pull straight up on it to remove the top cap and make sure it's clean, it's got a little "pad" and spring in there.

 

[tcpoob]

i found the rear diff breather and cleaned around it but couldn't pull the cap up and off after numerous counter-closewise turns. the cap can be pushed down a little and it springed right back. the base of the cap seems not round but intentionally shaped like a square so it doesn't come loose and off. the bolt the cap is on still has some threads left making you feel it's not completely threaded into the diff. i *guess* the breather might be okay since even before i cleaned around it, the cap didn't feel stuck.

on the other hand, under the rear diff, i saw this caulk like gray color stuff between the axle and the thick end of the flange (? is that the name for the cone like twisting part between the drive shaft and real axle, the front of which is narrow and back is wider ... ). i seem to always see oil around that caulk gap or maybe it's just oil running down and deposited there as it's a lower part of the diff, but now as low as the drain plug.

 

[notrayray]

i found the rear diff breather and cleaned around it but couldn't pull the cap up and off after numerous counter-closewise turns. the cap can be pushed down a little and it springed right back. the base of the cap seems not round but intentionally shaped like a square so it doesn't come loose and off. the bolt the cap is on still has some threads left making you feel it's not completely threaded into the diff. i *guess* the breather might be okay since even before i cleaned around it, the cap didn't feel stuck.

Breather looks fine, bounces back, and I think a little threads show from the factory, it's just a vent basically. No dirt, no worries.

on the other hand, under the rear diff, i saw this caulk like gray color stuff between the axle and the thick end of the flange (? is that the name for the cone like twisting part between the drive shaft and real axle, the front of which is narrow and back is wider ... ).

It's RTV silicone for the gasket between the housing and the differential is the part you called the flange. It's also called a carrier or a third member.

i seem to always see oil around that caulk gap or maybe it's just oil running down and deposited there as it's a lower part of the diff, but now as low as the drain plug.

I'm sure it's from the pinion seal leakage.

 

[tcpoob]

pinion seal leak

I'm sure it's from the pinion seal leakage

Thanks. Placed an order with local dealer parts dept so when i go to the mechanic who worked on it in April, i'll have less downtime waiting for parts.

For pinion seal leak, would the gear lube come out of the wider side of the carrier, like at the RTV silicone seal, or the narrower end of the carrier joining the drive shaft (u-joint?), or it could be either?

Thanks.