Recently pjick up a l989 Ranger 4x4 that was owned by a little old lady. Has about l50k on the motor and trans. I would say for the last three years it has been sitting.

My problem is that when at highway speeds the automatic transmission has a difficult time going into 4th gear/overdrive. At 55mph tack is reading about 3400 rpm. When overdrive finally kicks in the rpm drops to about 2400. Drove about 70 miles highway the other day. Most of the trip was running 3400rpm; during trip you could feel truck shifting in and out of 4th gear. You could seed the tack fluctuate between 3400 rpm and 2500 rpms and the truck had a slight jerk so you could feel the transmission shifting between gears. After about 40 miles truck stayed in 4th gear.; however the next day I still ran the higher rpm at speed.

Transmission fluid is full and appears clean (red) Fluid had only a very minor burn smell. ( I think thre trans fluid has never been changed.) Trans does not slip and kicks into passing gear fine.

Besides the obvious thing to change the filter and fluid is there something else I should do or know. Is the projblem with 4th gear a signal that I may ned a transmission soon or its is just a problem with the truck sittiong idle so long?

Thanks for your help on this

 

Forgot to mention in my original post. Ranger is a 2.9 liter 4x4 with automatic on colum, manual hubs if that matters.

 

Check the TPS sensor. Put a can of trans tune in there to free things up, and then change the fluid and filter, drain the torque convertor too. If that is a no go, go with the TPS sensor.

 

Hate to be stupid, but what is a tps sensor and where is it located?

 

A TPS sensor is a throttle position sensor, and its located up on the throttle body. It tells the computer how much gas you are giving it. If they go bad, i will not tell the computer the right info, and it will not shift right. If it tells it your are giving it more gas than what you actually are, it will hardly ever shift into overdrive. I would do the tranny flush first though.

 

Try this. When the tranny seems to hesitate shifting to OD, lightly tap the brake pedal, like you do with the cruise control to turn it off. If the tranny shifts into OD when you touch the brake pedal, you have a bad shift sensor. Like stated, though, engine problems like with the TPS will manifest into the tranny, too.

 

I will try some transmission cleaner--drive it a while then replace the flter.

Will the flilter be enough of a transmission flush??

 

I have the exact same scenario. Did you ever find a resolution?