TF727 shift shaft seal experience

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Topic author
letank
Posts: 4010
Joined: Wed Oct 03, 2012 9:16 pm
Location: SF bay area

TF727 shift shaft seal experience

Post by letank »

Posting it so it can be found when the mothership sinks, I posted onto Rick's original post, because it has the most useful infos

it is titled : Getting parts together to change the shifter seal on the 727

http://www.ifsja.org/forums/vb/showthre ... 9&posted=1

Rick is right, you are better off being ready for the continous dumping of trany fluid after removing the trans filter and loosening the valve body.

PUT THE TRANS IN NEUTRAL, and vehicle on a flat surface with wheel choke

Yes, I bought the tool to extract the shift shaft seal, but the tool did not bite into the interface metal/rubber, so after pounding, using an impact driver to try to drive the f#@er out... it was time to gather buckets and pans... drain trany oil, disconnect the kick down the speed selector rod and the return cooler line in the rear of the trans body so you can move your hands around... it is tight.

When you drop the valve body, a large spring will pop out with its holder - The Accumulator-... which may spring out of sight, it did for me and I had read the TF727 manual, but could not find the accumulator wedged behind the oil catch can....

I did not bother to move the parking rod (could not see the E-clip), so I left the Valve body dangling and drip all it could, while I attended the seal removal, the pick was useless, a 9/16 open end wrench was perfect to pop the seal out from above.

My shift shaft was very oily, no rust, but I still did a rub with 1000 grit wet/dry emery cloth.
Installed the new seal after cleaning, it was tricky as the lack of space give you a poor line of sight... lube the seal and pop the VB back not forgetting the reinstall the accumulator cylinder and its spring. For those doing this, may be new o-rings on the accumulator piston would be a wise choice. Then lifting all 4 wheels on wood blocks would be good too.

The real experience : after adding 3 quarts and idling in neutral, the level was at max and not changing, putting in any gear, there was no motion, such as no fluid, I let it warm a little more... trany temp was 120, and still no motion and fluid still at max...I try to drive around the block, major slippage, and fluid still at high... finally after idling in neutral for another 10min the fluid went down so I could add an another 2 quarts and be back to normal driving conditions.

for better description and photo, check binderplanet

http://www.binderplanet.com/forums/inde ... on.117876/
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (229 Kmiles... the running test lab)
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babywag
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Location: Land of Fruit Loops & Coconuts

Re: TF727 shift shaft seal experience

Post by babywag »

-Tony
'88 GW (aka Babywag)

candymancan
Posts: 3652
Joined: Tue Mar 22, 2016 11:32 pm

Re: TF727 shift shaft seal experience

Post by candymancan »

I did mine from up top. Was fairly easy
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)

Topic author
letank
Posts: 4010
Joined: Wed Oct 03, 2012 9:16 pm
Location: SF bay area

Re: TF727 shift shaft seal experience

Post by letank »

The tool could not bite into the seal

Image

the tool

Image

I tried Tony's approach, but my awl was awfull, ... could not resist... not tough enough, to poke thru the interface
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (229 Kmiles... the running test lab)

candymancan
Posts: 3652
Joined: Tue Mar 22, 2016 11:32 pm

Re: TF727 shift shaft seal experience

Post by candymancan »

I used a little pick like babywag showed.. That didnt work so then i us3d a tiny eye glass screw driver and lightly tapped the seal with a hammer to poke through it with the screw driver and pried the seal out.
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)
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babywag
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Joined: Fri Jun 08, 2012 7:29 pm
Location: Land of Fruit Loops & Coconuts

Re: TF727 shift shaft seal experience

Post by babywag »

Can't really see in pic, but my little pick/awl dealio is sharpened and helps grab a hold better.
The 'ole screw, or make a hole in seal to pry better, works well too.
Press fit seals gotta be mean as hell to 'em :mrgreen:
-Tony
'88 GW (aka Babywag)

Topic author
letank
Posts: 4010
Joined: Wed Oct 03, 2012 9:16 pm
Location: SF bay area

Re: TF727 shift shaft seal experience

Post by letank »

Thank you for the details, It will help somebody else tackling this common issue.
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (229 Kmiles... the running test lab)

candymancan
Posts: 3652
Joined: Tue Mar 22, 2016 11:32 pm

Re: TF727 shift shaft seal experience

Post by candymancan »

babywag wrote:Can't really see in pic, but my little pick/awl dealio is sharpened and helps grab a hold better.
The 'ole screw, or make a hole in seal to pry better, works well too.
Press fit seals gotta be mean as hell to 'em :mrgreen:

Mine is curved and sharpened as well but the seal was wedged in so good it was bending my pick. Thats why i had to use a mini screw driver
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)
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