BlackbirdLT4

Hi Guys,

New guy here hoping to get some help tracking down proper seals for my '96 LT4 ZF transmission. New clutch and solid flywheel (Zip Corvette kit- http://www.zip-corvette.com/catalog/...category/7949/ ) going in next week, and the trans is pretty greasy so I'm hoping to have the seals done at the same time, too.

I know everybody raves about ZFDoc for parts and knowledge. I left him a message yesterday and haven't heard back yet (haven't given up waiting, it's still early) but I'd like to hopefully get some parts in for the work next week.

Could any of you guys point me in the right direction for which seals to order in case I don't hear back from him?

What are everybody's thoughts on doing the Rear Main Seal while the flywheel is out? Again, where/what should I order? (I know, I'm a PITA)...

Thanks!

Mark in Maine

mtwoolford

Do it. The rear main seal is super easy; however, I also recommend replacing the tail shaft bushing; if you deal with ZFdoc get one of his "heavy duty bushings", its longer than the stock one and has more area to stabilize the drive shaft. It does require removal of the tailshaft housing from the transmission case which is easy, but do not attempt to press out the old bushing; it has a couple of dimples which press into the aluminum case; use a reciprocating saw and slice it lengthwise along where the oil return channel is, it will then pop right out. If you slice it along the oil return channel, the possibility of cutting into the tailshaft housing itself is eliminated. By the way, when I split the tailshaft housing away from the transmission case, I discovered that the gasket had been installed with a portion of it folded over onto itself...so mistakes do happen, even at the ZF factory.

oh, btw the rear seal is the same as a chevy turbo 400 rear seal, so there shouldn't be any issues there.

BlackbirdLT4

Thanks for the reply. I've emailed ZF Doc and called a few times but haven't gotten any replies.

Kurt from White Performance had the front and rear seals and gaskets for me. I just put the order in. I would like to try and get the heavy duty bushing however.

WVZR-1

The only US distributor for the Corvette C4 ZF parts is

http://www.rsgear.com/

Give them a call and discuss your needs/wants with them. I did many transfer case builds using RSG and through the years some manual trans parts. It's been many years but at the time I needed them they did well.

1985 Corvette

If you do the rear main seal, run the engine and check its function BEFORE you install the transmission and everything else. Even the brand new seals can leak because they sometimes just sit on the shelf for years before use. I had a brand new seal on a brand new built engine leak oil at a depressing amount just from idling....had to yank the transmission right back out in the lovely Florida summer heat. Lesson learned.

I got a replacement from a pretty good sized Chevy dealer and they handed me their only one piece rear seal in the house to me.....bag was dirty and showed signs of just sitting around for a long time, but seal had been caked in grease. I plunked it in and ran the engine quite a bit before putting the transmission back in. That ZF is heavy and no fun wrestling back in, even with a trans jack. May not be a bad idea to replace your pilot bearing if it didn't come with your clutch. Autozone has the rental tool to remove the old one. Works like a charm.

dizwiz24

ZFdoc has helped me out a bunch (As recently as 2012)

I think he does it more as a 'hobby'. So, I would not expect instantaneous responses.

This is not a big deal for me because usually I was doing big trans projects during ohio's winter.

That said, he always came thru with parts and whatever I needed!

Tom400CFI

X2. I recently used them for parts to rebuild the T56 in my wife's CTS-V...they were fantastic to work with.

GREGGPENN

Or, at least Bill has periods where he has to deal with other things. He may live with/near elderly parents in Arizona. I know he has talked about issues with them in the past (in personal communication). Something like that (or even vacation?) might be the answer.

QCVette

X3. I was doing some mix and match flywheels, clutches, bell housings, and transmissions to put my '96 back together. He was fantastic to work with and even spent some time talking to me about the differences and what works.

PS. Got it running again this week.
No more vibration from a bad balance flywheel.
And no more severe chatter from a bad pressure plate.
And the mix and match parts on the black tag/blue tag all went together and it shifts great again.

A big thumbs up for ZF Doc.

1985 Corvette

ZF Doc is the guy to work with. Stand up gear head that enjoys helping out. He happily worked with me and spoke with me many times over the phone despite me not making any sort of purchase from him or his shop. He even called randomly one day to check in on my progress installing a ZF. It's definitely a labor of love for him but he does stay busy so don't be offended if you get a voicemail and don't hear back. Try him by email as well.

whalepirot

I just called Bill, who answered the phone. He is the same ole Bill with his laugh and eagerness to assist, even tho he may/may not make any $ with his advice.

few in this hobby as as valued as he is, at least to me.

chadk

keep us updated. Looking at that setup as well for my 95.

thank you,
Chad

1985 Corvette

Next time you call him, ask him about the guy with a 1985 Corvette who had no business dropping a ZF in it. "Oh, THAT guy!....I need a beer just thinking about those phone calls".

bogus

Bill has always answered my questions. Great guy!

as an aside, the rear seal on the ZF6 is the same as the rear seal on a TH400.