SL/R129: 1994 SL500
07-29-2023, 10:38 AM
#1
Newbie
Thread Starter
Join Date: May 2021
Location: San Diego
Posts: 4
Likes: 0
Received 0 Likes
on
0 Posts
2012 S63 AMG
1994 SL500
My 1994 R129 won’t go into reverse after it warms up. It goes into reverse when it’s cold. Any ideas what the problem might be?
Thanks!
Thanks!
07-29-2023, 10:45 PM
#2
Super Member
This is most likely the dreaded reverse clutch seal wear disease. Lost my '95 w124 to this.
Reason it engages cold is that the fluid is thicker cold and the seal is ok. Once warmed up the seal does not do the job and pressure can not be built up for the engagement.
Did not know the R129 is also afflicted by this design defect. Mercedes used a plastic seal that eventually wears out. The rebuilt transmission should use the superseded metal seal.
Long story short it is a big job an will need the removal of the transmission. No easy fix for this one.
Most R129's are lower mileage so probably do not get to the operational life of the seal. Generally they go 150K miles or more.
Reason it engages cold is that the fluid is thicker cold and the seal is ok. Once warmed up the seal does not do the job and pressure can not be built up for the engagement.
Did not know the R129 is also afflicted by this design defect. Mercedes used a plastic seal that eventually wears out. The rebuilt transmission should use the superseded metal seal.
Long story short it is a big job an will need the removal of the transmission. No easy fix for this one.
Most R129's are lower mileage so probably do not get to the operational life of the seal. Generally they go 150K miles or more.
