I have a 1977 Dodge Aspen 2 Door Coupe that I have been restoring for the last six months. The other day ago I ran the vehicle for a test run. The transmission will go into all gears manually but when driving it only wants to stay in first gear. It doesn't want to go into second or third gear. I have looked on the top of the engine and on the bottom of the trans to see if anything has came off but I see no issues of any kind. Any advice would be greatly appreciated. I have no manual to refer too. Thank You.

 

You need to check the throttle pressure, kick down linkage that goes to the carb

 

You would not by any chance have a pic of how it should be hooked up under the hood on a slant six 225 3.7 would you? Would it help to post pictures of my engine? Cause I am clueless on this one. Thank You.

 

Scroll down and see the picture....

http://forums.hotrod.com/mopar-muscl...sible-problem/

 

If the linkage is adjusted correctly.
Maybe its a manual valve body setup
or the pistons for the pressuer regulation circuit are worn along with this the gear select piston and cylinder can also be worn these are a common problem with old valve bodies or the seals are hard and leaking
PACT.com has kits that repair worn piston cylinders
does the trany come out of gear when idle at a stop light?
revs up and clunks into gear when leaving from a stop light?
it also may be a worn pump housing ..not enough pressuer.
if u can check the pressuer levels at the tap ports this will narrow it down a bit
Just throwing out some ideas from past experiences