Date registered: Sep 2013
Vehicle: W123 280CE
Mentioned: 0 Post(s)
Quoted: 21 Post(s)
The pain of adjusting a 722.1 transmission
Attention! Attention! Calling all transmission-DIY'ers/pro's for help.
I already posted my transmission smooth shifting quest in the W123-section, but most of the people over there seem to have the newer 722.3-transmission.
A short introduction to my transmission problems:
Whiplash-gearshift. No really.... these gearshifts (were) eating away my driveline. My diff went from noise-free to humming within 10.000km's. I tried everything externally. Setting the modulator-pressure, changing the transmission oil, tweaking the throttle linkage. All to no avail. The modulator-adventure only led to early and stacked (hard) shifts.
So... I finally dove in the deep (Dutch expression?!) and decided to pull the valve body apart and search for clues in there. Stretch was so helpfull to provide me with a spare valve body. The last valve I took apart had indeed a broken spring. I believe it was the 'main' accumulator. From what I've seen, the 722.1 has only one accumulator for all shifts. (Whereas the 722.3 has multiple for its various gears)
Long story short... I replaced the spring, put everything back together and the difference was night and day (compared to what it was). Only downside: the shift-points shifted upwards.
2-3 => 35 kph (FSM: ~28 kph)
3-4 => 65 kph (FSM: ~43 kph)
Although the replacement of the spring helped a lot, it still isn't perfect. When I'm cruising in the suburb at a speed limit of 30kph, I - ofcourse - use very little throttle. This causes the car to 'jump' in third gear at 35. However... a bit more throttle and all is well.
Does anybody have any experience with the shifting characteristics of this gearbox? Preferrable one that is attached to a gas-engine.
W116, W114/5, (early) R107 all use this transmission.
So... how does your 722.1 shift?