A/T won't shift until warm

[Ranger1221]

94' Ranger 4x4 4.0 Ext A/T

Hey I'm having a problem that is only getting worse as it gets colder outside.

When starting my truck in the morning or after it's been sitting for a couple hours, it will not shift from 1st to 2nd until it has warmed up. It goes into all gears fine from a stop (drive, reverse, neutral, etc) but will not upshift until it has warmed up. Once its warmed up it will shift through all the gears just fine and is no longer a problem. I put it into drive and it will stay in 1st revving high rpms until it warms up then will finally upshift. SOMETIMES when I put it into drive it will start in 2nd gear, but will downshift to 1st if I accelerate hard enough.

I have replaced the vacuum modulator, but it did not fix it. I did notice however on the new part that the nozzle the vacuum lines slips over had a much smaller diameter hole than the stock piece. The transmission fluid is full and the color isn't bad. I replaced the fluid and filter less than year ago.

I really need to figure this out soon as its taking longer to function normally with the colder weather setting in. Any help or ideas is really appreciated!

 

[Transman304]

Sounds like the governor is sticking. Might try a bottle of red lube guard. But something is failing to make debris to hang it up. Let us know what you find.

 

[Ranger1221]

Thank you for the reply Transman! After doing more searching this time specifically about the governor I found plenty of posts about the same issue. Sounds exactly like my problem. Ill give an update next weekend after I work on it.

 

[Ranger1221]

Just wanted to update in case anyone else has the same problem.

The governor was indeed the culprit. When I pushed the valve in from the side it would stick and the tension from the spring wasn't enough to push it back out because it has some crud in there. Just cleaned it thoroughly with some steel wool and soaked in solvent for a bit. Works great now, no more delayed 1st-2nd shifts. Also flushed the transmission with new fluid and plan on installing a 2nd remote trans filter for better filtration.

Just pulled the rear driveshaft, drained the transfer case,unbolted front driveshaft from transfer case, removed transfer case, and was able to get it easily through the tail shaft housing.

Also had time to swap out the 2 piece driveshaft for a 1 piece. No more vibration taking off from a stop.

 

[alwaysFlOoReD]

Thanks for the update.