According to the service manual downloaded from ZF.com and the Ford 1996 service manual I have the input shaft oil seal can be changed without having to disassemble the transmission. Has anyone ever done this? I have just completed a ZF swap, could not be happier with all aspects of the trans swap except leaking front seal.

"Note: For 4.9L and 5.8L engine applications the through-bore of oil seal is designed such that oil seal can be removed without having to dissemble the transmission if removal and replacement of oil seal is all that is required. "

 

It is quite simple like the book says. Just pop out the old seal, and put in the new one

 

I was hoping it was quite simple like the book says but how many times has quite simple turned into a major task. Just wanted someone who had done it themselves to tell me it was as simple as it appears. Thanks.......

 

Ok got trans out and old seal out. However(BIG HOWEVER) new seal from Ford or Autozone is 50mm x 35 mm. The hole size around the shaft is 42mm, so I'm assuming a special(non-stock seal will have to be found. You can't push a 50mm seal in though a 42mm hole. I've thought about die grinding lip out of the way so stock seal will slide into place. Input folks please.

 

I can't remember for sure but I want to say I replaced the input seal from the inner side of the case. Can you tell if there is a lip on the bell housing side of the seal bore? If there is not a lip, maybe you have an input seal for another engine configuration? Is the ID of the seal the same as the old one?

 

Yes there is a lip on bellhousing side, that's the 42mm size. Yes the inside diameter is the same as the old, 35mm. I'm looking at a different seal with dimensions of 42x35x8, using the lip to hold seal in place. I'm assuming that's what the Ford service manual and ZF manual are referring to when it says to drive new seal in flush but not into the transmission. Thank you for the reply.

 

How were you able to get the old seal past the lip?

 

I worked the old seal until it broke and then grabbed the end with needle nose pliers. Pulled it out basically straighting as it came out. Since my last post I gave up, opened case and installed new seal. Trans has been re-assembled but not back in truck yet. Wish I had opened it to start with but manuals said I could do it from the bellhousing side. Thanks for the replies and I appreciate any input.

 

What did you use to seal the case? Loctite makes an anaerobic flange sealant (I think it's 518) that is supposed to be better to use than RTV silicone. The RTV will corrode the aluminum according to the Ford service manual.

 

Brought the gasket maker from Ford per their part number. Boy, they're proud of it too.

 

I bet so. I went looking for it at the local dealer and he said it was superseded or something so I ended up getting the loctite 518 for about $20 from Fastenal instead.