Hard shift out of park, speedo off

[SimonStern]

OK, got the "new" transmission in (89 regal, 2.8l, auto), car runs fine for the most part. The problems I am encountering are:

 

1) When you start the car and shift it to reverse/drive it jolts the car pretty hard and there's an audible "clunk", kinda like worn out dog bones allowing to much engine rock but worse than that ever was. It shifts hard from 1st to 2nd then after a little driving it smooths out except a jolt at around 10mph when coming to a stop and I guess it's downshifting. Once you park again for even 3 minutes and start it up it jolts pretty hard again. I'd really like to get rid of this.

 

2) Since the new trans the speedometer is off by at least 10 miles an hour, it seems the faster I go the more off it is, I know I was doing a little over 50mph and it said I was doing 37 . That should be just an adjustment that needs to be made somewhere right?

 

Thanks go out for all help in advance .

[cutlass1991]

1. My transmission does almost exaclty the same things that you mentioned. I just thought stuff like that was normal for old automatic transmissions. I never remembered mine being smooth and I have had it since 28K miles.

 

2. I don't think you can make adjustments to the speedometer. I think that the vehicle speed sensor must be changed.

[Prospeeder]

do you have a New Vacuum Modulator on there? if its an adjustable one, it would be WAY to hard, or vacuum to it is plugged or somthing, so shifts are way too hard.

[Dan94Z34]

u Can't adjust the speedo on thease cars, like you could in the old days of just changing the little plastic gear in the tranny. They use that electronic speed sensor on the tranny so the speedo is closer to the correct speed. I would also check the vacume modulator or, maybee there is some crap in there pluging up the tansfiler?

[Pabz]

I put in a used tranny and was getting JOLTs, this didnt go away until i rebuild the dogbones with poly inserts on the engine side. One dogbone was messed to begin with. Check/fix your dogbones, jolt should go away unless something is seriously messed with the tranny, speed issues? WTF, where did you take it??

[Regal_GS_1989]

i don't know if the signal from the speed sensor goes directly to guage cluster, or if it goes to the ECM, than to the cluster from there, but it is possible that the car that the tranny came out of came equipped with smaller wheels than your car has. Which could cause the speedo to read a speed slower than what you actually are doing. Or, it is possible that the tranny has a different FDR than what your car originally came with.

[DaveFromColorado]

the speed-o problem may be that the gear that drives the speed sensor in the transmission is the wrong size for your requirement - that'd cause it to be off.

 

as for the other issues, I'd do as the others suggested, check the detent cable (cause you've got the manual downshift cable on that transmission) and the vacuum modulator on the side of the trans.

 

--Dave.