1995 GM Cadillac STS 4T80E trani 94 shift ratio A 76 force motor malfunction problems
It's OK, adam's apple,
Now let's go and look the picture :
http://cadillac-sts.skyrock.com/37.html
All disc & drum & band new and dip inside the transmission . . .
Right ! You are really the god of this kind of transmission ! 
Thanks for advice, it was good help for me...
Now let's go and look the picture :

http://cadillac-sts.skyrock.com/37.html
All disc & drum & band new and dip inside the transmission . . .

Originally Posted by Adams' Apple
Be careful handling this trans. It weighs almost 300 pounds!
If you decide to pull it out, be sure to replace the seals in the channel plate for the input sprocket, as these are the #1 problem with this trans. Another problem is the forward clutches(#s 816 & 817 in your diagram). In every single 4T80E I have done, there has been at least one of the clutches with the friction material flaked off of it.
It would be advisable to get an overhaul kit, and just do the entire trans while it is out. Just replacing the band(if that's what it needs) isn't worth the trouble of pulling the trans out of the car, imo.
Also, depending on how bad the band is burned, it may have damaged the reverse clutch drum (# 500 in your diagram). I've seen many of those drums turn blue from the heat of the band slipping, which causes them to no longer be round.
The low/reverse band(# 13) also has issues with the friction lining flaking off, so inspect it carefully.
The rest of the trans is pretty solid, and we don't see many problems from any of the other parts, unless there has been some abuse, or major neglect.
You should be able to see part of the reverse drum with the lower pan off. You might be able to see if there is evidence of the band burning from there. There is an opening in the case there shift linkage is, and part of the drum is visible.
Another note....on the shift linkage wire that connects the case linkage to the valve body, there is a plastic clip that holds the wire to the case linkage...be VERY careful removing that wire linkage, as the plastic clip will break very easily.
Be careful handling this trans. It weighs almost 300 pounds!

If you decide to pull it out, be sure to replace the seals in the channel plate for the input sprocket, as these are the #1 problem with this trans. Another problem is the forward clutches(#s 816 & 817 in your diagram). In every single 4T80E I have done, there has been at least one of the clutches with the friction material flaked off of it.
It would be advisable to get an overhaul kit, and just do the entire trans while it is out. Just replacing the band(if that's what it needs) isn't worth the trouble of pulling the trans out of the car, imo.
Also, depending on how bad the band is burned, it may have damaged the reverse clutch drum (# 500 in your diagram). I've seen many of those drums turn blue from the heat of the band slipping, which causes them to no longer be round.
The low/reverse band(# 13) also has issues with the friction lining flaking off, so inspect it carefully.
The rest of the trans is pretty solid, and we don't see many problems from any of the other parts, unless there has been some abuse, or major neglect.

You should be able to see part of the reverse drum with the lower pan off. You might be able to see if there is evidence of the band burning from there. There is an opening in the case there shift linkage is, and part of the drum is visible.
Another note....on the shift linkage wire that connects the case linkage to the valve body, there is a plastic clip that holds the wire to the case linkage...be VERY careful removing that wire linkage, as the plastic clip will break very easily.

I strongly suggest obtaining a Cadillac Seville Transmission, Transaxle & Transfer Case Unit Repair Manual for guidance. Also consider a transmission overhaul kit.
The rear cover is called a Transmission Case Extension. To remove it, first remove the speed sensor and ground wire, unbolt the cover, then there is a roller thrust bearing and scavenge tube.
The differential carrier is next. It is important to first rotate the manual shaft counterclockwise to place the transmission in park and prevent the differential from rotating. Then unbolt the differential carrier.
The final drive carrier is next. Push on the output shaft in order to expose the left side gear snap ring and remove the side gear and thrust washer. Remove the final drive carrier, thrust bearing, and sun gear. The final drive internal gear comes out with an internal snap ring. The output shaft come out the left side of the case.
Adams Apple was right on and he knows more about these transaxles than me. Hopefully he will come back to help you.
The rear cover is called a Transmission Case Extension. To remove it, first remove the speed sensor and ground wire, unbolt the cover, then there is a roller thrust bearing and scavenge tube.
The differential carrier is next. It is important to first rotate the manual shaft counterclockwise to place the transmission in park and prevent the differential from rotating. Then unbolt the differential carrier.
The final drive carrier is next. Push on the output shaft in order to expose the left side gear snap ring and remove the side gear and thrust washer. Remove the final drive carrier, thrust bearing, and sun gear. The final drive internal gear comes out with an internal snap ring. The output shaft come out the left side of the case.
Adams Apple was right on and he knows more about these transaxles than me. Hopefully he will come back to help you.
Last edited by memez; Jul 6, 2010 at 04:46 PM.
Looks like it was pretty burnt up! Glad you got it taken care of. One thing....On the gasket for the center support to the channel plate, there are TWO different designs. I hope you were careful, and matched the new gasket to the old one. Both styles come in the kits.
Seems like you've got it all back together, and ready to go back in the car. Let us know how it works!

Seems like you've got it all back together, and ready to go back in the car. Let us know how it works!
Looks like it was pretty burnt up! Glad you got it taken care of. One thing....On the gasket for the center support to the channel plate, there are TWO different designs. I hope you were careful, and matched the new gasket to the old one. Both styles come in the kits.
Seems like you've got it all back together, and ready to go back in the car. Let us know how it works!

Seems like you've got it all back together, and ready to go back in the car. Let us know how it works!






Last edited by memez; Jul 9, 2010 at 07:47 AM.
I'm on the way to go home (I stay hotel this night)
I had done 1000 km , no problem and enjoy drive Cadillac !
And :
New best time for my 100 % street Mustang with title and full interior :
10.97 @ 198 km/h and 1.6 @ 60 foots !
Very good week-end !
I had done 1000 km , no problem and enjoy drive Cadillac !
And :
New best time for my 100 % street Mustang with title and full interior :
10.97 @ 198 km/h and 1.6 @ 60 foots !
Very good week-end !




