Shift problem

[Crank It Up!!!]

Got a 84 4x4 Ramcharger last week. Trans wont shift automaticly. Wont downshift when I came to a stop. Have to downshift manually and then manually up-shift into second and third. The shift itself although done manually feels fine. No slipping. Dont know when (or if) the trans was serviced. Fluid looks and smell O.K. Truck set up for several years prior to purchase. It will downshift upon excelleration from 3rd to second and then upshift to 3rd automaticly. To be honest, I really havent had time to look at or drive it very much. I'm thinkin its something simple like a stuck a valve. I assume it uses a detent cable. Somebody rebuilt the carb to git it running after being stored for so long and I havent checked the cable yet. Figured it wouldnt downshift upon excelleration if it wasnt hooked up. ?????????????

Any ideas???

Thanks.

Robert

 

[fishy68]

Robert are you saying the problem just seems to be 1st and 2nd gear but 2nd to 3rd shift works ok? If so it sounds like the 1-2 shift valve is stuck in the valve body. Might even be a broken spring on the valve. Maybe try putting some trans additive in it such as K&W Trans-X. It might free it up if it's just stuck. If it don't you'll have to drop the pan and valve body and take it apart and give it a good cleaning and or replace the spring.

 

[Crank It Up!!!]

Robert are you saying the problem just seems to be 1st and 2nd gear but 2nd to 3rd shift works ok? If so it sounds like the 1-2 shift valve is stuck in the valve body. Might even be a broken spring on the valve. Maybe try putting some trans additive in it such as K&W Trans-X. It might free it up if it's just stuck. If it don't you'll have to drop the pan and valve body and take it apart and give it a good cleaning and or replace the spring.

No not exactly to answer your question. The truck will not go if you just put it in drive. Its trying to start in 3rd gear. You have to put it in 1st gear to start going and manually shift it into second and third. Once in third gear/drive, if you mash tha gas, it will downshift to second automaticly and then back into third automaticly as it should. The problem seems to be that it fails to downshift when you come to a stop.

I have tried this ........

came to a stop in drive/3rd
tried to go forward again
would not go as if still in 3rd gear
manually shifted into first gear
roll forward a few feet in first gear and stopped again
move shifter into drive
again would not go
manually shifted back to first gear
started going but have to shift manually into 2nd and 3rd
drove at 45-50 mph
pressed the gas pedal down untill it downshift automaticly into second
it then shifted automaticly as it should back into third.

Apparently the detent is working and it will shift automaticly if activated by the detent. It just will not downshift properly when I come to a stop. I agree that there must be something stuck in the valve body. I'll try the Trans-X. Gotta admit I'm kinda concerned about adding a cleaner or having to change the fluid in an old tranny not knowing when or if it has been changed as it should have. They usually dont last long once you run new fluid through um for a short while and wash all the fine particles off the clutches. If it goes out completely, I do have at my disposal another tranny in a 87 truck. Same motor in both.

Thanks for your help.

Robert

 

[fishy68]

Robert I have to say that I haven't seen this problem yet and I have been rebuilding torqueflites for over 25 yrs. Whenever I see one that won't downshift after coming to a stop they won't kick into passing gear either. That would indicate a governor problem. Chrysler doesn't call it's kickdown linkage a detent like GM does but it does have a mechanical kickdown that works in conjunction with the governor to regulate the shift speeds and downshift. You are correct in thinking that if it wasn't hooked up it wouldn't kick down. The operation your describing sounds like it has a manual valve body except that it retained the kickdown feature which isn't possible on any manual valve body that I know of. I believe I would start by running a pressure check on the governor. The 1/8 inch pipe plug on the lower drivers side of the extension housing is the governor pressure test port. In drive with the brakes applied and engine idling it should be no more than 1-1/2 psi. Closer to zero is best. Much above 1-1/2 psi won't let it downshift when stopped. If it is above 1-1/2 psi I would inspect the governor for stuck valve(s) or a broken spring. You probably know this but in case you don't the governor is located on the output shaft so you have to remove the tailshaft housing to access it. If you don't find the governor stuck valve(s) it has to be a problem in the valve body. I don't think there is any mechanical problem that will cause this. Good luck.

 

[Crank It Up!!!]

Fishy68, thanks for your input and advise. I also believe I have a stuck valve or broken spring in either the gov. or valve body. Dont have time to mess with it right now but will look into both.

I appreciate your taking time to help.

Thanks again.

Robert

 

[fishy68]

Fishy68, thanks for your input and advise. I also believe I have a stuck valve or broken spring in either the gov. or valve body. Dont have time to mess with it right now but will look into both.

I appreciate your taking time to help.

Thanks again.

Robert

No problem man. Always glad to help when I can. Good luck with it.