SL/R129: 1994 SL500
MBWorld Fanatic!
Joined: Mar 2016
Posts: 1,379
Likes: 197
From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
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 The rebuilt transmission should use the superseded metal seal.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 The rebuilt transmission should use the superseded metal seal.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.
