Rear end is leaking fluid!

[d0n_3d]

not again...yet another rear end problem i am having...

i just had my rear end serviced due to bad carrier bearings...they put it all back together and they put in this really thick blue rear end fluid...they told me to change it after about 500 miles so the new bearings could break in...i changed it to mobil 1 synthetic (the stuff is like water) and now it's leaking big time all over the place...my mufflers, exhaust pipes, rear end housing are all covered in fluid oil...it even drips to the floor when the car sits for a long time...i never had this problem before i took it to the shop...did they screw something up? do i need a new pinion seal as well because that's the exact spot where i see the massive oil puddle...right under where the driveshaft connects to the rear...

it wasn't leaking with the thick blue fluid though...should i go back to that and not worry about the seal???

i forgot to mention that when i put in the new mobil 1 synthetic gear oil i had to add 3 quart bottles plus a 4 oz bottle of posi additive and it STILL wasn't full at the top of the fill hole...does this mean anything? did my overfilling cause the leak and now its coming out places it shouldn't be due to overfilling or is the seal just bad...i don't know what to do here...i don't want to spend another 200 bucks on having this pinion seal replaced if necessary after spending 300 to have all carrier and pinion bearings replaced...i guess i will try the thicker oil first and see what happens...how much oil is supposed to be in the rear end??? do you fill it to the very top???

 

[SuperSix]

ANother instance where dino oil works great.

You should fill it until the fluid comes out of the fill hole, there's no set amount. Make sure you're on a level surface when you do it. Did you uses a cover gasket? Or did you just use silicone? I always use a gasket.

Is it chattering on low-speed turns?

I use standard gear oil and hypo additive. Is it leaking from the pinion seal?

 

[turbosam6]

Are you using one of the TA rear end girdle cover things? If so, don't fill it to the top hole, it will leak out. I'm wondering if you overfilled it somehow and it blew out of the breather hole in the housing. Happened to me on my Z28 one time. Otherwise, it sounds like you've got some bad seals or gaskets. I've never heard of any thick blue stuff for bearing break in, either.

 

[SuperSix]

Originally posted by turbosam6
Are you using one of the TA rear end girdle cover things? If so, don't fill it to the top hole, it will leak out. I'm wondering if you overfilled it somehow and it blew out of the breather hole in the housing. Happened to me on my Z28 one time. Otherwise, it sounds like you've got some bad seals or gaskets. I've never heard of any thick blue stuff for bearing break in, either.

True..

You should defiantely NOT use Mobil1 for any "break-in" though.

I see no real advantage to synthetic oils anyway, if you change you dino oil like you should, you won't have any problems.

 

[d0n_3d]

does not chatter at all...it used to make a loud rubbing noise but that was because of the bad carrier bearings...now i have no noises at all except for when i start to slow down from highway speeds i hear a faint whine noise...i guess that is lack of fluid since i am leaking it all over! i will change the oil to a thicker non synthetic and see what happens...man that mobil 1 stuff is as thin as water i swear...how is that called oil? no wonder it's leaking...and yes it's leaking RIGHT at the pinion seal...i can see it dripping right from there...not on the seal ring itself but it's dripping from the very end of the part that turns with the ds...ushaped holder

 

[d0n_3d]

man i don't like mobil anymore...i am going to start using a non synthetic oil in my motor as well...i have been using the mobil 1 synthetic (which is also like water) and i leak a little bit at the rear main seal...for higher mileage vehicles use dino oil!!!

 

[SuperSix]

Did they replace the pinion seal when they did the carrier bearing?

Use dino and some posi additive, you should be fine.

Now if it leaks w/ 85w+ gear oil, there's a problem with the pinion seal. I'm a bit wary of the work done giving that they used very heavy oil afterwards, possibly to mask a leak? Don't ASSUme anything until you replace the gerar oil. And put a drain plug in the pan and make sure the magnet is still there while you have it out.

 

[d0n_3d]

well like i said the fluid that i drained out was very thick...it was blue and he told me that since he drained out synthetic when he was working on the rear end that he would put synthetic back in it...but how is synthetic that thick? oh well i will just get some real oil put in there...which brand/weight oil should i use? i want the thickest possible without having problems with performance...or does the weight really matter in rear ends?

 

[SuperSix]

Originally posted by d0n_3d
well like i said the fluid that i drained out was very thick...it was blue and he told me that since he drained out synthetic when he was working on the rear end that he would put synthetic back in it...but how is synthetic that thick? oh well i will just get some real oil put in there...which brand/weight oil should i use? i want the thickest possible without having problems with performance...or does the weight really matter in rear ends?

I'm sure I'll get heat for this - but I use standard 85w-140 (I think) hi-performance from Advanced/Discount Parts. Last posi additive I used was Trans-X. The oil says it's for posi rear ends, but I figure some additional posi lube couldn't hurt.

No special brand names.. Seems to work great. Chattered before, silent now. I did forget to put a drain plug in though.

 

[Louie L.]

I use the same cheappo gear oil from Advance.I ve used them all...from Amsoil to Mobil one. Just couldnt feel a difference but to my wallet.

 

[d0n_3d]

well guys i changed the fluid to valvoline synthetic 85w140 which is much more thicker than the mobil 75w90 stuff i had in there before...i only put in 2 quarts this time and then added 4 oz. of gm posi additive...it's still leaking...it leaks several drops overnight in the garage...i am not sure if it's leaking during driving...but when i drained the mobil 1 stuff before there was at least 2 quarts that came out...so i guess it wasn't leaking that bad? it's leaking right at the pinion seal area too...so i guess i have to get that replaced huh...is it easy to do by myself or should i just take it in...i don't want to drain the fluid AGAIN...this would make like the 5th time this summer

 

[SuperSix]

Originally posted by d0n_3d
well guys i changed the fluid to valvoline synthetic 85w140 which is much more thicker than the mobil 75w90 stuff i had in there before...i only put in 2 quarts this time and then added 4 oz. of gm posi additive...it's still leaking...it leaks several drops overnight in the garage...i am not sure if it's leaking during driving...but when i drained the mobil 1 stuff before there was at least 2 quarts that came out...so i guess it wasn't leaking that bad? it's leaking right at the pinion seal area too...so i guess i have to get that replaced huh...is it easy to do by myself or should i just take it in...i don't want to drain the fluid AGAIN...this would make like the 5th time this summer

Sounds like the shop that worked on it wasted the seal.. I don't think it's a job you want to do yourself..

And I wouldn't let the same shop fix it.

Good Luck..

 

[JimBlackGN]

My 87 GN has 91k miles, too and it had an opened rear end. I took it to Wayne Gubbs in Louisville Ky which was only 1 hour and 45 minutes drive for me. He swamped it with a new posi Eaton unit. He added some shims and race bearings to the unit and closed it up with gasket. Filled it and added the friction modifier. Drove it home on very same day and did a few burn outs. It has been two months now and no leaks in sight. I would suggest you to check with Wayne Gubbs (Gears Are Us) about this issue. I am sure you will be satisfied with his service and his expertise in rear ends. He also has a generous 86 GN in his shop!!

Jim

 

[d0n_3d]

if my leak continues i will check him out...i went out in the garage this morning and there wasn't a single drop of fluid on the floor under the pinion seal

i will check it again tomorrow morning for more leaks...it seems to leak once and while now...weird...

 

[SuperSix]

Originally posted by d0n_3d
if my leak continues i will check him out...i went out in the garage this morning and there wasn't a single drop of fluid on the floor under the pinion seal

i will check it again tomorrow morning for more leaks...it seems to leak once and while now...weird...

It will have to get thoroughly hot to leak I bet..

Good luck!

 

[d0n_3d]

well i daily drive my car...i drove it to work and back earlier today and then i put it in the garage right away...so let's see if it is still leaking by tomorrow morning...

 

[TurboJim]

I'm finding that with the heavy trucks, packing the seals with wheel bearing grease has yielded a zero-leak rate. Might ask them to do that when you bring it back.

 

[Chuck Leeper]

Break in lube??

Break in lube?? Sounds like a bunch of crap to me... Did they charge you more because it's a "Special" oil??

I'm looking at the Strange gear install instructions... I see nothing to say that a break in lube has to be used!!

Jim T said:
"I'm finding that with the heavy trucks, packing the seals with wheel bearing grease has yielded a zero-leak rate". This is a good idea to help w/ break in.
IF they replaced the seal & drove it in w/ a sledge, or did not lube it's contact surface, it could be damaged either by it being bent, or burned from no lubrication on start up.
Another problem could be the pinion yoke is worn at the seal contact area.

BTW, 3 qts is too much lube!!

A whine noise on decel is due to the way the gear is set up. Coast side pattern may be off. However, once a gear set is run in, it's unlikely you would be able to change the pattern much.

If you change the seal, use care not to overtighten the pinion nut. Doing so will upset the preload on the brgs and could cause premature failure....
Was the rear built w/ a shim type spacer, or the common crush sleeve?? I always use the spacer/shim option. It eliminates the problem w/ the crush sleeve getting mashed down w/ 15psi launches on a t-brake!!!

 

[d0n_3d]

well it's still leaking that's for sure...just went in the garage right now and looked on the floor...there's a good sized puddle there...right under the pinion seal area...i am trying to find my receipt from where i took it in last time...i probably won't be able to have this done again without paying for it correct? sigh...guess i got screwed over

 

[d0n_3d]

hmmmm kinda weird...i just called them up and they said they would change out the seal for free...i just wonder if they know that they were trying to mask it and now they got caught and they feel sorry for me or something...oh well at least it's free, do they have to drain the fluid again to change the pinion seal? i swear i have spent 60 bucks on just fluid changes alone in the past couple months because i have had to drain the fluid about 5 times!