rear differential fluid leak?

[tcpoob]

2005 SR5, V6 4WD, 107,500 miles

A few month ago, I'd some bearing in the rear diff replaced to fix whining airplane like noise problem. All the differential fluid (center and rear) was also replaced with Mobil 1 Synthetic. It just caught my attention that the oily watery puddle on my garage floor is right beneath the rear diff. This might have happened for a while by now. I took some pictures. Both the "pumpkin" rear diff module and the underside and back of the skid plate to its left (looking from rear) look oily. How do I check the fluid level - should I check both the rear diff and center diff (transfer case)? Do I run a lot of risk wrecking the diffs if I keep driving it? I am going to see the mechanic who did the work this year next week but I want to find out what's going on before then by myself if I can just check the fluid level. Is there any light if the fluid level is low or , a stick measure like the engine oil ?

Please advise. Thanks.

 

[Justinlhc]

First I'd make sure the drain is tight and not leaking.

Second I'd make sure the breather is unclogged and free of mud/dirt.

Third I'd unscrew the fill hole and fill it up until fluid comes out of it. That's how you know it's full(on level ground of course).

Yes, you run a risk of destroying your rear end if you run it dry. That would cost you. Check the drain and breather and post what you find.

 

[tcpoob]

socket size, breather?

Thanks. Am doing some searching in the t4r forum. what i learned so far is there's a fill and drain plug on each diff ( guess i am most concerned about the rear diff, less so on t-case center diff ...), drain on bottom and fill on top. don't know anything about breather yet. just this weekend i did my oil change so i assume the fill and drain of differential plug is similar to the engine oil drain plug? i don't have a good jack but perhaps i can back the ride up to a pair of rhino ramps and get under it to check? what're the socket sizes for the rear and center diff drain and fill plugs?

when i called the mechanic, he was like "i told you to bring it back after 200 miles" (after the bearing service months ago), "and you just voided your warranty" (of his rear diff repair work).

First I'd make sure the drain is tight and not leaking.

Second I'd make sure the breather is unclogged and free of mud/dirt.

Third I'd unscrew the fill hole and fill it up until fluid comes out of it. That's how you know it's full(on level ground of course).

Yes, you run a risk of destroying your rear end if you run it dry. That would cost you. Check the drain and breather and post what you find.

 

[tcpoob]

found some more info

Found some more info on how to check / replace the fluid and various socket size and part #s, thanks to OP snowbizx's thread and all your contribution.

http://www.toyota-4runner.org/maint...ntial-transfer-case-fluids-pics-included.html

 

[CJ3Flyr]

This thread is about modifying the rear diff breather but it'll show some pics and give you a good idea of where it is. Good luck!
http://www.toyota-4runner.org/off-roading-home-monst4rs/123-breather-install.html

 

[tcpoob]

breather

thanks Chris. the picture links in that thread in page 1 are all broken. from the text i glanced over i got some basic ideas. i don't off road although i am in the northeast so in general i shouldn't worry about breather mod, right - unless the original ones are clogged for some reason.

 

[CJ3Flyr]

thanks Chris. the picture links in that thread in page 1 are all broken. from the text i glanced over i got some basic ideas. i don't off road although i am in the northeast so in general i shouldn't worry about breather mod, right - unless the original ones are clogged for some reason.

I wouldn't worry about the mod although it won't hurt. I maintain the stock check-valve type breather is tough on the wheel seals. Totally your choice but there's a minor advantage (theoretically anyway) to doing it.


The FJCruiser is VERY similar mechanically to a 4Runner. This thread may have better/more pics for you... SCUBA Driver Transmission, Transfer Case, Rear Differential & E-Locker Breather MOD - Toyota FJ Cruiser Forum

 

[Justinlhc]

when i called the mechanic, he was like "i told you to bring it back after 200 miles" (after the bearing service months ago), "and you just voided your warranty" (of his rear diff repair work).

I hope you don't plan to bring this guy any more work. :nono:

You should be able to squeeze under there with no jack or ramps to check.

I would suggest going for a drive to get it nice and warm and remove the fill plug or the breather to listen for air. If you get a significant PUFF of air come out it's probably your breather being clogged.

 

[tcpoob]

can gear lube burn pinky?

thanks justin and chris for the tips.

i do have a set of rhino ramp and a somewhat steep driveway (a decline if leaving house at around 25 to 30 degree angle). so it's an art to get it some what level.

will remove the spare and check the fluid. i keep buying tool sets but i am always short on something. this time, the 24mm socket - my largest is 21mm or 22mm. ridiculous. no torque wrench either. may pick one up from lowes.

i suppose the gear lube fluid can get really hot after a good ride? so sticking pinky there can be a bad idea? may just have to do this after a short warmup.

on the garage floor, the puddle underneath the real diff is not as oily/dark as the other one under my engine oil drain plug. i took it to be water from A/C initially but it occurred to be it's always under the rear diff and i looked up and saw moisture/oil around the rear diff drain and back and bottom of skid plate.

sounds likes before serious damage to gears are done, if it's a clogged breather it's an easier fix, but if it's the some of the seals and gaskets inside the differential, then the real axle has to be disassembled and therefore labor intensive / costly? or maybe just as simple as using fresh crush washer and tightening the drain?

 

[CJ3Flyr]

thanks justin and chris for the tips.

i do have a set of rhino ramp and a somewhat steep driveway (a decline if leaving house at around 25 to 30 degree angle). so it's an art to get it some what level.

will remove the spare and check the fluid. i keep buying tool sets but i am always short on something. this time, the 24mm socket - my largest is 21mm or 22mm. ridiculous. no torque wrench either. I'd prioritize getting it filled. Firmly tight with a 1/2 drive ratchet is close enough. Don't throw your whole body into a 1/2 drive breaker bar or anything just "good and tight". It doesn't require tremendous amounts of precision. A torque wrench is the 'right way' to do it of course but for the fill/drain plug I wouldn't worry about it. may pick one up from lowes.

i suppose the gear lube fluid can get really hot after a good ride? so sticking pinky there can be a bad idea? may just have to do this after a short warmup. Not too hot, not scalding by any stretch. Your pinky will survive

on the garage floor, the puddle underneath the real diff is not as oily/dark as the other one under my engine oil drain plug. i took it to be water from A/C initially but it occurred to be it's always under the rear diff and i looked up and saw moisture/oil around the rear diff drain and back and bottom of skid plate.

sounds likes before serious damage to gears are done, if it's a clogged breather it's an easier fix, but if it's the some of the seals and gaskets inside the differential, then the real axle has to be disassembled and therefore labor intensive / costly? or maybe just as simple as using fresh crush washer and tightening the drain? I suspect it is the 'simple fix'. There's a total of 5 potential leak points: Two plugs (drain & fill), Pinion seal (where the drive shaft goes into the rear) and wheels seals out by the tires. Note: Wind does funny things. I would NOT panic yet if it's a little wet where the driveshaft goes in. Focus on the plugs and clean the area with some Brake Clean and then just watch it.

:cheers:

 

[tcpoob]

what's that oily bar?

I managed to get under the 4Runner (2005, v6 SR5 4WD, 107.4k miles). didn't check the differential as i saw another part (like a bar or axle higher than the rear axle) that's very wet (oily?) and maybe slowly dripping over the differential.

in fact, i took the spare tire off to make it easier and noticed part of the top side wall presumably under the dripping part also has some deposit of that fluid/oil.

that bar/axle that's dripping seems to have about two small holes underneath it ( the bar is not the rear axle right? coz it doesn't extend all out to the rear wheel hub and is *above* aka higher than the rear drive axle where the rear diff is connected to). I took bunch of pictures but it's hard to get a good shot being so close to the object. i am sure you gurus know what it is.

so based on my inspect, it's mostly not the axle (wheel ) seals that're leaking. the rear diff fill plug is very dry but the drain plug, well, it's the lowest part there so although it's wet it doesn't prove anything. the pinion seal is hard to tell although it's moist as it's also beneath that dripping "bar".

So I figured i wouldn't complicate things by checking the rear diff lube level assuming it's from that dripping bar over the top. btw, my 15/16 inch socket seems it would work for the rear diff fill plug although spec says 24mm, close enough i guess.

please advise what i need to do next - should i still check the rear diff? again the leaked fluid is not too oily, much clear/ lighter, almost watery compared to engine oil drips.

 

[tcpoob]

another picture

hit the limit of 8 attached pics so here is the last.

 

[CJ3Flyr]

Fill the diff and take it back to the guy who rebuilt the rear. He "failed" on the pinion seal.

 

[Justinlhc]

Fill the diff and take it back to the guy who rebuilt the rear. He "failed" on the pinion seal.

Yup. When the pinion seal leaks it spits everywhere. It leaks onto the driveshaft as it spins and it gets thrown all over. It should stink like hell.

I'd fill the differential back up before doing anything else. You don't want that going dry.

Pinion seals are easy and quick to change.

 

[tcpoob]

what's that bar in front and above the rear axle, that's oil and dripping? i thought the drive shaft connects to the rear diff ( at the pinion) so if it's the leak source, why would the "bar" above it and higher all wet and dripping?

thanks.

Fill the diff and take it back to the guy who rebuilt the rear. He "failed" on the pinion seal.

 

[tcpoob]

interesting. in my case it doesn't stink or i didn't smell anything. i actually used paper towel to soak up the leak on garage floor and tried it. could me be not being sensitive in smell.

what's the name of that "bar" that's oily and dripping, shown in lots of pics? it's parallel to rear drive axle but sits higher from ground and a foot or so forward towards the front of the ride than the rear axle? and that silver pan like aluminum piece, that seems to be under the gas tank?

I've not mount the spare tire back yet so that makes it easier for me to check and fill the rear diff gear fluid tomorrow. i was in denial.

is it typical when repair work like mine was done 6 months ago, when a bearing (or a few) in the rear diff were replaced, that new seals should have been used? and new drain fill plug gaskets also? i would think now, if the pinion seal is replaced, that would require the gear lube be refilled in the real diff all over again? would replacing pinion seal require taking the real axle apart - guess not?

thanks.

Yup. When the pinion seal leaks it spits everywhere. It leaks onto the driveshaft as it spins and it gets thrown all over. It should stink like hell.

I'd fill the differential back up before doing anything else. You don't want that going dry.

Pinion seals are easy and quick to change.

 

[notrayray]

interesting. in my case it doesn't stink or i didn't smell anything. i actually used paper towel to soak up the leak on garage floor and tried it. could me be not being sensitive in smell.

what's the name of that "bar" that's oily and dripping, shown in lots of pics? it's parallel to rear drive axle but sits higher from ground and a foot or so forward towards the front of the ride than the rear axle? and that silver pan like aluminum piece, that seems to be under the gas tank?

I've not mount the spare tire back yet so that makes it easier for me to check and fill the rear diff gear fluid tomorrow. i was in denial.

is it typical when repair work like mine was done 6 months ago, when a bearing (or a few) in the rear diff were replaced, that new seals should have been used? and new drain fill plug gaskets also? i would think now, if the pinion seal is replaced, that would require the gear lube be refilled in the real diff all over again? would replacing pinion seal require taking the real axle apart - guess not?

thanks.

The rear bar is your rear stabilizer or sway bar. It's got gear oil on it from the rear pinion flinging the oil out as it rotates.

A new pinion seal would have been used.....or should have if it wasn't.

What was his reasoning for asking you to come back after 200 miles?

The pinion seal can be replaced without removing the rear diff from the vehicle.

Drain and fill plug gaskets are rarely replaced unless they are leaking.

 

[tcpoob]

Thx for ID'ing the sway bar for me. you know when had a tire rotation done or new tires put on, they usually ask you to come back after some miles presumably to make sure the lugs are tight etc. I suppose it's a similar reason. i paid him $10 or $20 more than he asked on his handwritten receipt to show a gesture of appreciation of that work. he definitely didn't say anything about voiding the warranty if you don't return for the checkup. i thought he said "if you want, come back for a quick check at your convenience ...".

BTW, what's typical warranty duration of a machine shop / auto shop for this type of work? He replaced the rear diff bearings (due to noise) on April 7, 2010. I am not sure he replaced the pinion seal as part of that work - i looked at his handwritten receipt, there's $5 "sealer" part charge, and $250 for bearing and installation kit. The rest is $700 labor and tax. No mention of warranty however in the handwritten receipt either.

I looked up partznet, the pinion seal is < $13.

The rear bar is your rear stabilizer or sway bar. It's got gear oil on it from the rear pinion flinging the oil out as it rotates.

A new pinion seal would have been used.....or should have if it wasn't.

What was his reasoning for asking you to come back after 200 miles?

The pinion seal can be replaced without removing the rear diff from the vehicle.

Drain and fill plug gaskets are rarely replaced unless they are leaking.

 

[Justinlhc]

It pisses me off to hear about clowns like that who lie and screw good customers. It makes them all look bad. I don't take ANY of my vehicles to shops unless it's for tires/alignments/balances. So many snakes out there.

Pinion seal is very easy to change and cheap. There are 4 bolts with nuts that attach the drive shaft to the flange. There will be a large bolt that holds the flange to the pinion. I'm not sure what size that one will be, but it's kinda big. Once you remove that you can pull the old pinion seal off and carefully slide a new one on. You need to make sure you tighten the large bolt exactly where it was. A torque wrench will be needed to do it properly, although I have done it without one and just made sure it threaded on exactly where it was. A shop shouldn't charge you very much to do this. Try to find an HONEST shop this time. :nono:

 

[notrayray]

You need to make sure you tighten the large bolt exactly where it was. A torque wrench will be needed to do it properly, although I have done it without one and just made sure it threaded on exactly where it was.

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.