Ford Muscle Cars Tech Forum banner
1 - 3 of 3 Posts

·
Registered
Joined
·
1 Posts
Discussion Starter · #1 ·
Hey guys, finally had to make a post because I couldn't find the answer on someone else's! I have been researching this question for a bit but can not seem to find someone with the exact issue I am having, and I am certainly not a transmission guy.

1965 Galaxie 500 with the Green Dot Cruise-O-Matic, "rebuilt" a couple years ago before I bought it. It is working absolutely perfectly except for the following issues:

1. The transmission does not like to up-shift on its own in any gear selection, however if I CHANGE the gear (such as Drive to neutral, or Drive to Green Dot) it will then begin operating as it should, shifting up and down throughout the drive with absolutely no issue. However, if I stop somewhere and turn the car off, I will have to repeat this process. This is not a huge deal, but I have gone through every inch of this car and its one of the last items I have not repaired, so i would like to.

2. Likely unrelated, but I am also experiencing a leak from the transmission after sitting, which imagine is the converter backfilling. I plan to replace the rings on the filler and see if there are other leak points.


If you have any ideas they are always welcome!
 

·
Registered
Joined
·
256 Posts
Are you driving normally on the big "green dot"? That is your drive selection. That era of Ford automatics were designed differently than most in that the first "drive" gear (small dot) is not your normal drive gear and instead starts the car in 2nd gear. So, in that position, you won't feel an upshift until you get to 3rd. They supposedly made this for driving on slick/icy conditions to avoid spinning the tires. The big green dot selection is the second stop right next to "L", and will start you off in 1st. Just wanted to clarify that...sorry if that's old news, and you probably already knew that.

Beyond that, if your transmission is internally in good shape, your vacuum modulator may be worth checking. It may stand some adjustment to firm up the shifts. Sometimes the shifting is so soft that you can't even feel it happening. Wouldn't be terrible to check that the vacuum hose is connected properly and that there is no leakage of fluid from that. Those can and do fail and definitely will make shifting not happen as expected. There is a rubber diaphragm that can rupture or crack and will keep it from working correctly. The adjustment is done with a small, flat-blade screwdriver on the back of the unit inside the hose nipple. A clockwise turn will firm the shifts.

Fluid levels are also surprisingly important for proper shifting.

One other thing is the band adjustments. There is a procedure outlined in the shop manual for this. I had a Mustang with a C4 that fell out of adjustment here after sitting one winter. It needed re-adjusted, and that solved the issue.

These may not be your issues, but a few simple things to verify first.
 

·
Registered
Joined
·
1,882 Posts
Are you driving normally on the big "green dot"? That is your drive selection. That era of Ford automatics were designed differently than most in that the first "drive" gear (small dot) is not your normal drive gear and instead starts the car in 2nd gear. So, in that position, you won't feel an upshift until you get to 3rd. They supposedly made this for driving on slick/icy conditions to avoid spinning the tires. The big green dot selection is the second stop right next to "L", and will start you off in 1st. Just wanted to clarify that...sorry if that's old news, and you probably already knew that.

Beyond that, if your transmission is internally in good shape, your vacuum modulator may be worth checking. It may stand some adjustment to firm up the shifts. Sometimes the shifting is so soft that you can't even feel it happening. Wouldn't be terrible to check that the vacuum hose is connected properly and that there is no leakage of fluid from that. Those can and do fail and definitely will make shifting not happen as expected. There is a rubber diaphragm that can rupture or crack and will keep it from working correctly. The adjustment is done with a small, flat-blade screwdriver on the back of the unit inside the hose nipple. A clockwise turn will firm the shifts.

Fluid levels are also surprisingly important for proper shifting.

One other thing is the band adjustments. There is a procedure outlined in the shop manual for this. I had a Mustang with a C4 that fell out of adjustment here after sitting one winter. It needed re-adjusted, and that solved the issue.

These may not be your issues, but a few simple things to verify first.
+1

One more note if your transmission is leaking out of vent tube, on the old cast iron Borg Warner transmissions (FX, MX) that is an indication of aerated fluid caused by a worn pump. Aerated fluid, depending on the severity can also cause intermittent problems with the valve body.

Cheers
 
1 - 3 of 3 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top