Since this is a 260e, will a transmission from a 190e 2.6 fit? I just so happen to have a spare, and using that would be MUCH cheaper than fixing those 2 teflon rings you mentioned.

trans service would still be the cheper attempt, i have actually only seen the teflon rings cause issues when they are incorrectly installed, not saying thy won't but i just havent sen them fail, how many miles on the car?

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1967 250 S
1967 280SE
1968 250S
1971 280 SE
1973 220
1974 280 S
1975 450 SEL
1976 220 D
1979 300SD
1983 300 SD
1985 230 TE euro
1986 280SL
1986 500 SEL euro
1986 190E 2.3
1990 300 SE
2003 C230 K
2004 C230 K
1987 560SEL
1987 300SDL now in canada
2005 C230
1998 C43 AMG Sold to DON
1993 190E 2.6
300TD Former daily driver Totaled
current:
R320 CDI
Ram 2500 Cummins

Don't know, I'm a diesel man since 1960. Check the numbers. Example:The 300SD has a 722.303. According to my book, the 260e and the 190e 2.6 have the same transmission. (722.409) Reddog