the car 85 300d 722.3 shifts perfectly when warm except for a jarring thunk when you lift off the throttle from accelerating in third gear only. it happens as third is disengaging? it also has a cold 2-3 flare. ive just read all the superior threads and am getting the kit tmw. any ideas. everything else is checked trans pres, bowden, vac.

Have you owned this car long? and Has the trans fluid been changed recently? - i.e. per interval recommendation on this forum

I would think if you had a vacuum leak, all shifts would be harsh. Are you saying the 3-4 shift is hard? If 2-3 shift is a tooth jerker, I am not positive if this trans has one (it should), but a broken 2-3 shift accumulator spring would cause a hard shift/clunk - all the time. A cold flare may be a separate B2 concern, though. When accelerating through until a 2-3 shift, or any shift, and then quickly letting off the go pedal will cause a hard shift/clunk in most all transmissions, which I consider a normal characteristic. My 2003 Econoline, 1999 Suburban, 1985 300SD and countless customer cars all do the same thing under these conditions. Hard acceleration increases line pressure to apply clutches/bands harder to keep from slipping under heavy engine loads. A sudden decrease in throttle pressure will allow the trans to shift, but remember that pressure inside the hydraulic circuitry of the trans is still high and bleeds of that circuit slower than you letting off the pedal at the time it makes a shift. Among other things, a shift accumulator dampens the pressure of that shift for ride quality by smoothing shifts (fewer cases of whiplash) But, they can only do so much. If you keep accelerating through to 3rd gear and let off easier, it may then shift to 4th with less of a jerk. It all has to do with when you let off and shift points of the trans. at the time you take your foot off the pedal.

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Thanks,
Mark in NC

"Spark plugs?...We don't need no stinking spark plugs!"
1985 300SD "Der Silberne Schlitten" 420,000 mi


Wish these were diesel:
2003 Ford Club Wagon 130,000 mi

check your driveshaft for play.

the Superior kit is designed to fix the downshift clunk if thats all it is.

Firstly, my guess is that the observation was when the vehicle was in second gear and it was performing a 2-3 shift when you lifted off the pedal.

This behavior is quite common in all of the 722.3 transmissions and they don't like trailing throttle for the 2-3. If you keep your foot in it, the shift will be perfectly fine. It tends to show that the driver has planned poorly and utilized a bit too much power and then suddenly needs to let off.

There are several things that can be done, however, by raising vacuum levels, if the trans doesn't exhibit any 2-3 flares at anytime. If it currently flares at all...........this adjustment won't work for you and you're between a rock and the proverbial hard place.

We'd need some vacuum levels at the modulator under various operating modes to make any kind of realistic advice. We never get that info, because the effort won't be made, and therefore all the advice given is generic.

That's pretty simple info to get my T'ing into the modulator vacuum line, running the hose out of the hood at the cowl and laying the MityVac in front of the windshield as you go for a drive.

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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

...........simple for you............