TH400 Shifter leak question
Thread Starter
Racer
Joined: Jul 2001
Posts: 361
Likes: 9
From: Dresser WI
TH400 Shifter leak question
I'am at the last stretch with my frame off i put in new front and rear seals in my tranny and hooked up the linkage and filled it up. I went out to the shop to finish up some other projects only to find a large puddle under the car, i found it was leaking from the shifter shaft that comes out of the case. I did a search on th400 here on the form and as sujusted bought a new seal i pulled the pan only to find no seal for the shift rod? :confused: it appears the rod goes thru the case with no seal at all. could someone please tell me what i need to do now. This is a 73 coup with the orignal tranny. Thanks for your help. :chevy
Thread Starter
Racer
Joined: Jul 2001
Posts: 361
Likes: 9
From: Dresser WI
Re: TH400 Shifter leak question (johns73)
Thanks for the post. When i took the pan off there was no seal or place for a seal. The shaft just goes thru the case, it has never leaked there before. I was able to purchase a seal but it dosen't go on the shaft. And whats up with this? :lurk:
Melting Slicks
Joined: Nov 2000
Posts: 2,738
Likes: 53
From: Bogart GA
Re: TH400 Shifter leak question (johns73)
There is a seal and it is located in the case. It fits into the shifter shaft boss from the outside of the case. It is hard to see and looks like part of the case. I purchased a special tool which extracts the old seal and installs the new seal without removing the shaft. Call a local trany shop, they may let you borrow one. I will send you mine if you cant find one locally.
Drifting
Joined: Nov 2002
Posts: 1,688
Likes: 201
From: Loveland, CO
Re: TH400 Shifter leak question (KJL)
I have this same problem on the 400 in my truck. The shop manual outlines how to replace it, but it involves removing the shaft from inside the pan. If there is a way to do it from the outside, that would be great.
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Thread Starter
Racer
Joined: Jul 2001
Posts: 361
Likes: 9
From: Dresser WI
Re: TH400 Shifter leak question (johns73)
Thanks for the information, If i understand you correctly the shaft has to be pulled and then the shaft seal will be revieled? The seal i picked up is about 5/8th in round does that sound right? I would be intrested in borrowing you tool to fix this problem if you need a deposit i would be willing to send one. Thanks John :cool:
Melting Slicks
Joined: Nov 2000
Posts: 2,738
Likes: 53
From: Bogart GA
Re: TH400 Shifter leak question (johns73)
You do not remove the shaft. This tool has an external tappered thread on one end and slips over the shaft and you screw it into the old seal. Then, the other end is internally threaded to accept a bolt. As you screw the bolt in, it bears against the end of the shifter shaft and extracts the seal, pulls it from the boss. Works kinda like a gear puller. The other tool is more or less just a cylinder that you use to tap the new seal into place. Make sure you clean the boss out very well(spray some brake cleaner into the boss) and put thin coat of permatex sealer around the inside of the boss with a Q-tip. This makes it easier to tap in the new seal and makes a oil tight seal to case joint. If you give me your address, I will send it to you. When you see it, it will be clear as to how it works.
Drifting
Joined: Jun 2000
Posts: 1,955
Likes: 2
Re: TH400 Shifter leak question (KJL)
There is a seal and it is located in the case. It fits into the shifter shaft boss from the outside of the case. It is hard to see and looks like part of the case. I purchased a special tool which extracts the old seal and installs the new seal without removing the shaft. Call a local trany shop, they may let you borrow one. I will send you mine if you cant find one locally.
Thanks,
Jeff
Melting Slicks
Joined: Nov 2000
Posts: 2,738
Likes: 53
From: Bogart GA
Re: TH400 Shifter leak question (no_radio)
I tracked down a place here in Atlanta that sells mostly to shops. I called them and asked for a shifter shaft seal tool and they knew exactly what I was looking for. I think it cost around 35 bucks. Beats the heck out of dropping the pan. And removing the shaft is not small undertaking.
Le Mans Master
Joined: Jun 2002
Posts: 8,339
Likes: 24
From: I can walk to MA
Re: TH400 Shifter leak question (no_radio)
For those without the tool, you remove the pan, undo the shifter shaft inside,
slide it out. Then, you can carefully pry the old lip seal out and tap the new one
into the bore. Clean up the shaft if needed. Install is the reverse of removal.
:seeya
slide it out. Then, you can carefully pry the old lip seal out and tap the new one
into the bore. Clean up the shaft if needed. Install is the reverse of removal.
:seeya
Drifting
Joined: Jun 2000
Posts: 1,955
Likes: 2
Re: TH400 Shifter leak question (NHvette)
For those without the tool, you remove the pan, undo the shifter shaft inside,
slide it out. Then, you can carefully pry the old lip seal out and tap the new one
into the bore. Clean up the shaft if needed. Install is the reverse of removal.
:seeya
slide it out. Then, you can carefully pry the old lip seal out and tap the new one
into the bore. Clean up the shaft if needed. Install is the reverse of removal.
:seeya
I seem to recall that there was quite a bit to removing the shaft, including removing the valve body. Wasn't a big deal, but if the tool is $35 I'd rather do it that way.
Thanks,
Jeff
Tech Contributor
Joined: Aug 1999
Posts: 15,156
Likes: 3,965
From: Connecticut, USA
Re: TH400 Shifter leak question (73'Vette)
ATEC makes the tool,number T-1001. TH400 shift lever seal remover-installer. My price is $36 + shipping. I don't know if they sell direct or not but the web site is http://www.atec-trans-tool.com
Gary
Gary
Pro
Joined: Aug 2002
Posts: 705
Likes: 0
From: South Central MI
Re: TH400 Shifter leak question (gtr1999)
Maybe we could all go in on it and share it around. I doubt if I'd need to use it again in my lifetime. In the end we could sell it or donate to the website or something. It would ned up costing us a few dollars for the tool and a few for shipping and we'd all be happy instead of having another tool laying around that we'll never use again.
[Modified by Freepop, 3:02 PM 3/29/2004]
[Modified by Freepop, 3:02 PM 3/29/2004]
Racer
Joined: Dec 2003
Posts: 399
Likes: 0
From: Haslet,Texas
Re: TH400 Shifter leak question (gtr1999)
ATEC makes the tool,number T-1001. TH400 shift lever seal remover-installer. My price is $36 + shipping. I don't know if they sell direct or not but the web site is http://www.atec-trans-tool.com
Gary
Gary
Drifting
Joined: Jun 2000
Posts: 1,955
Likes: 2
Re: TH400 Shifter leak question (73'Vette)
I called my transmission guy and he said he doesn't use the tool because it tends to chew up the shaft. I am going to just drop the pan and change the filter while I'm in there.
Jeff
Jeff
Melting Slicks
Joined: Nov 2000
Posts: 2,738
Likes: 53
From: Bogart GA
Re: TH400 Shifter leak question (no_radio)
Yes if I recall it did scratch the shaft a little, I just wet sanded the area with 600 grit paper. Make sure to inspect the inside of the tool for burrs and sand smooth. The place that gave me the most problems with leaking was the plastic kick down switch connector. What a PITA. That has to be removed from the inside....even the new o-ring did not fix. I finally popped it out and caoted it with gasket maker and pushed ot back in place. That did the trick. Now the only leak I have is from the PS control valve.
