Daugther's 84SD. When she got it last spring upshifts were occurring too soon. I adjusted the bowden cable, upshifts were a little high but I left it there thinking it would give her a little more quick acceleration on city streets where she drives it back and forth to school. Drove it a couple of days ago and noticed it wasn't upshifting to 4th on city streets. So today I took a couple of turns out of the bowden cable. It still wasn't shifting to 4th in the 40mph limit to I took it out on the freeway. It wouldn't upshift to 4th for the first mile or so despite going 60mph and about 4000rpm's. Tried moving the shifter to neutral thinking the linkage might be off but it went into neutral so the D position seems ok. Drove a little further and finally it upshifted to 4th. Coming home it was upshifting into 4th fine.
All that to comment that it appears that if you adjust the bowden cable to get high rpm shifts and then drive the car for months at a time under conditions where 4th gear is not attained (my daughter's commute to school), the car gets into a habit of only using 1-3 and doesn't like going into 4th. I hope I have now reconvinced the car that 4th gear is a perfectly satisfying place to be.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

............only you could have lectured this transmission and convinced it to perform as designed.


I think I'll lecture the transmission on the SDL and see if I can convince it to stop leaking transmission fluid.............but, I already have a sense of what it will tell me.............

My car has been doing this same thing.... I am trying to tame it like you did in hopes it will learn....

Try some Trans X too see if the tranny needs loosened up. If it works then change fluid in the tranny including the torque converter

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1977 300D Lost coolant while someone else was driving
1983 300D Can't run without oil
1985 300SD (gone but not forgotten)
1990 300TE 4matic Sold
1991 Yamaha Venture
1975 Kawsaki 250 triple
1974 Honda 200CL
1951 8N Ford
2008 Wildfire 650C