9 3/4" rear end posi spilling fluid out of the vent hose?

[brad]

Hi guys I have a 83 f150 2wd that'snot stock . I'm not sure on the rear end and what it came out of . I just know it's a 9.75 and it has a positive unit installed. All of the seals where blown out and I had them replaced . I got it home and found my vent hose was plugged (probably why the seals were gone) so I cleared it out , now fluid is comming out of the tube ? Maybe he filled it with the wrong fluid for posi?? Any suggestions ? Thanks

[fastEdsel]

Wow, 9:75? I hope that's a type "O". I own a 1959 Mercury M350 with a 4:75 and that's the lowest ratio I have ever seen in any Ford. But to answer your inquiry a plugged vent could blow out your rear seals. But just one would relieve pressure but all three seals? That's if I can imagine the right rear diff. If the wrong oil was installed at some point in its life, I have heard that the oil can foam up as a reaction if the previous oil was not all cleaned out and that could force oil from the least point of resistance and that would be the vent tube. Interesting topic, keep in touch about how it all goes.

[brad]

Sorry I mean Ford 9 3/4 rear end not gears.. I am new to Ford's and am trying to learn the lingo the gearing is stock 3.00 my mechanic said. The previous owner put a posi differential in it. I've heard the posi can cause more pressure than normal in the rear end. ? Some guys say pull the vent nipple and shave off the end a bit a reinstall it .. not sure how that would fix it but I'll try whatever will work. Sorry for the confusion.

[BobbyFord]

Did you check the fluid level?

[brad]

No why you think he over filled it?

[BobbyFord]

No why you think he over filled it?

Possibly. I've never seen one leak out the vent.
I have a 9-3/8 with the posi additive in the oil and it doesn't leak.

[radioactivelarry]

Does the rear end make any noise? It would take a lot to get it hot enough to blow that thick fluid out the top vent. What kind of fluid did he put in it? If it's too thin that may be a problem or if it is over filled. Amsoil sells a synthetic for ford posi's with an additive. They also sell the additive separately. If not Amsoil the other brands sell synthetic that is compatible with limited slip. Is it a true limited slip or is it a locker?

[brad]

He said he put what the book said to run whatever that is but I'm sure it's not synthetic because he said lets try full synthetic after it happened . It is a locker I'm told buy the last owner. Also when he replaced the pinion seal he installed a speed sleave but when I brought it home only a mile away it was spilling oil real bad from the pinion seal . I took it back and he said the speed sleave broke and he removed it but it should be fine without it. He said he's never seen that before it split down the center. Now it leaks a little but not bad. It doesn't make any bad noise imo.

[BobbyFord]

He said he put what the book said to run whatever that is but I'm sure it's not synthetic because he said lets try full synthetic after it happened . It is a locker I'm told buy the last owner. Also when he replaced the pinion seal he installed a speed sleave but when I brought it home only a mile away it was spilling oil real bad from the pinion seal . I took it back and he said the speed sleave broke and he removed it but it should be fine without it. He said he's never seen that before it split down the center. Now it leaks a little but not bad. It doesn't make any bad noise imo.

I'd be getting a second opinion. A new pinion seal shouldn't leak at all. Doesn't sound like a competent mechanic. JMO

[tnlprt]

Factory you will NOT have a locker.It would be a Traction loc. Not even close to how a locker operates.
Figuring out what rearend you have helps a lot.
If your mechanic does not remember what grease he put in your rear end....... Get a new mechanic.
If he installed a speed sleeve then removed it and said it would be fine ....Get a new mechanic.
Is the hose for the vent run up to the frame on your truck?
Blowing grease out the vent tube is a sign of an overfull rear end.

[brad]

I'm sure it's a locker installed , it's not factory. Yes the vent tube runs up to the frame and was on the bar that goes from one side to the other. It's like a channel on top of the bar and oil filled the whole bar and made puddles on the floor on both sides of the truck the size of softballs. I took the hose and put it in a plastic bottle to watch and catch fluid. It has only leaked a small amount since the big spill.
As far as the leaking new seal I'm thinking I'll have my NEW mechanic install a sleeve and see what happens. Maybe he'll use the correct fluid too.

[ultraranger]

If gear oil is leaking from around the O.D. of the pinion seal, a little Ultra Black RTV applied to the outside of the seal before it's installed will stop this.

If the gear oil is leaking from around the seal that the driveshaft companion flange is sticking out of, it sounds like the flange has grooves worn into it by the pinion seal. A new companion flange will fix this problem without the band-aid fix of installing a speedy sleeve.

[brad]

I'm positive it is a groove in the shaft he even said it was there. He removed the 1st sleeve because it Broke in half in one mile of driving ?? I'll have to look into the real fix Thanks