TH400 seals
Thread Starter
Instructor
Joined: Jan 2003
Posts: 188
Likes: 2
From: Flowermound Tx
TH400 seals
In an effort to permantly drain the pink lake that resides under my 74 I'm going to get the external seals replaced. I've redone the pan & filter. That helped very little. What do the external seals consist of as far as where are they located and how many are there ??? I'd like to have an idea so when I take it for repair they will cover everything yet not change any internal seals since the trans is working great.
Thanks for your help,
Scott :cheers:
Le Mans Master
Joined: Mar 2002
Posts: 7,456
Likes: 2
From: Coming home from Luckenbach Texas
Re: TH400 seals (Porch40)
Your transmission will have to be removed to do this job. There are seals at the front and rear shafts, the shift shaft, and the speedo cable. There are also other potential places for the tranny to leak, like the cooling line connections. Shop around, talk to the people, get quotes. And most of all, avoid those "national" chains, unless you have lots of money to blow! :lol:
Safety Car
Joined: Aug 2001
Posts: 3,685
Likes: 202
From: Waterford Mi
Re: TH400 seals (page62)
The only seal that can not be changed without pulling the trans is the front seal. The shifter shaft seal can be changed but it takes a special tool to remove it. You will want to have the shaft checked out for rust and wear before you replace the seal. There is a plastic piece that the down shift wire attaches to. It has an O-ring. To remove it you need to remove the pan and push it out from the inside. The rear seal is replaced after removing the drive shaft. You should chnge out the bushing in the tail stock if the seal is leaking badly. The speedo cable seal has an O-ring and a seal inside the sleeve. The dipstick tube is know for leaking. It has an O-ring. New style drip stick tubes have a rubber seal which work a lot better.
Drop the front dust cover and look for oil leaking around the torque convertor to seal if the front seal needs replacing before you make the decision to pull the trans.
Drop the front dust cover and look for oil leaking around the torque convertor to seal if the front seal needs replacing before you make the decision to pull the trans.
