Vent/Breather in a ZF-5 Transmission?...

[Rreemo]

Hey Guys,
I had to have the ZF in my 97' F350 rebuilt, finally got it back this week, and in the truck last night...made it about 5-miles on a test drive before fluid starting gushing out of the rear seal....got it back in the shop and took a look....I also had some trans fluid inside the inspection cover on the front behind the flywheel....so it's coming out of both ends! I'm thinking this thing has to have a vent/breather on it somewhere, and wondering if it may be clogged.

Anyone know where that vent might be?

The builder I used is here local, place called "Standard Transmission & Gear Inc." out of Fort Worth (NOT recommended BTW)....these guys told me 1-week turn around up front....that turned into a month, then after I picked it up I notice that it looks all new & clean not because they hot-tanked it and actually cleaned up the case...nope, they just spray painted over all the old dirt, grime, grease, etc....as well as the ID tag. I also see that they re-used the rear thrust nut...that big "1-time use" nut that holds the rear yolk. Anyways...to make matters worse, I've gotten the thing back in the truck to find it gushing fluid ($9/qt Amsoil all over the bottom of the truck and on the ground)....and all this after paying these yahoo's over $1500 to build it. I called this morning and their only answer is to pull it back out and bring it back to them.

Considering they did spray paint it, I'm wondering if maybe they clogged the vent with paint....but I have yet to be able to find any sort of vent on it.

[JimD]

I've done several trans swaps and don't recall one

[shumpertdavid]

I believe some of them vent through the dipstick tube, they have a small hole just below the stick level that acts as a vent.

[thesource]

No vent on it. It should vent through the shifter. Did you over fill it?

[Rreemo]

Nope, exactly 3.4 qts. I'm pulling it back out....its got to go back to those idiots.

[thesource]

Leaking out the front seal is either due to them tearing the seal lip as they installed the front case or you have an alignment issue pushing the input shaft over enough to allow fluid past the seal.

As for the rear seal, usually it will only leak if it too is torn or possibly bent during installation. It could also be a worn out yoke allowing fluid to leak past the lip of the seal.

Reusing the nut is common practice. With some locktite, it should be fine.

[shumpertdavid]

Disregard my response as ignorance owned me and I didn't realize it was a stick.

[Rreemo]

Leaking out the front seal is either due to them tearing the seal lip as they installed the front case or you have an alignment issue pushing the input shaft over enough to allow fluid past the seal.

As for the rear seal, usually it will only leak if it too is torn or possibly bent during installation. It could also be a worn out yoke allowing fluid to leak past the lip of the seal.

Reusing the nut is common practice. With some locktite, it should be fine.

The bad thing is that the leak was one of my primary complaints when I took it to them....but it wasn't nearly as bad as it is now. I'm betting they didn't replace the seals in it.

[JimD]

They prob just painted it,lol

[thesource]

The bad thing is that the leak was one of my primary complaints when I took it to them....but it wasn't nearly as bad as it is now. I'm betting they didn't replace the seals in it.

Possibly. Did you replace the pilot bearing in the crank shaft? I would also look to make sure both dowel pins are in place on the back of the engine.

[Rreemo]

Possibly. Did you replace the pilot bearing in the crank shaft? I would also look to make sure both dowel pins are in place on the back of the engine.

Yeah, I converted it from the dual mass flywheel to a new Luk single mass setup...the kit came with everything, including a new pilot. The pilot with this kit presses into the flywheel instead of the crank, though. Both dowels were indeed still in place on the mating surface. However, the only odd thing (at least I thought it was odd), was that there were no dowels in the flywheel to help center the pressure plate....no holes for anything in the new flywheel except the 8 flywheel bolts. I know that wouldn't cause any centering issues with the disc/input shaft...at least not after the first time the pedal is pressed, but I still found it odd b/c I've run into lack of pressure plate dowels causing a vibration on a couple other occasions...in different applications.

Nevertheless I don't think we had any binding issues up front, b/c it went in so smooth....really didn't have to monkey with it at all, it just slipped right in-place. No evidence of any bind when I pulled it back out this morning either.

I think what we're dealing with here is the result of a rushed job...forgot the new seals or just didn't install them right. The reason they had it ~4-weeks is b/c they claimed that all of their builders fell ill with the flu, at the same time. So they got back logged with work, and then tried busting everything out last week when they had their crew back....he said they hired some "temps" too, to help with the backlog. So who knows what kind of monkey was stacking this thing together.

Anyways....I yanked it back out this morning and got it to them just after lunch time. He said they would put me ahead of everything else and turn it back out ASAP. Hopefully I'll hear from them early day tomorrow with the diagnosis. I'll update here once I find out.

My confidence isn't very good right now....I'm afraid of getting it back and having it leak again. That would really suck.