This item was previously posted in the Transmission Forum but received no replies so I thought I'd try it here.
I am the second owner of a 1999 Ranger XLT 4 cyl with
28,600 miles and Ford factory rebuilt 4R44E transmission (about 8000 miles) with 1-2 shift problem. Original transmission failed after time warranty expired and original owner had it replaced. Local dealership will not honor transmission warranty since I am the second owner.
Under very light acceleration at low speed the 1-2 shift does nor occur until 20-28 mph. After it shifts, many times it immediately downshifts to 1st and may stay in 1st to over 30 mph; other times it may shift 1-2 hard at about 25 mph and then immediately shift 2-3. Under normal acceleration it seems to shift ok or slightly hard at about 15-17 mph.
Fluid, filter, and 1-2 shift solenoid have been replaced by Lincoln-Mercury dealer technician who says "everything checks out ok" but I just don't belive it's right. Fluid level is correct to "hot mark"; speed sensor must be ok since ABS, cruise, and speedometer work normally; No "Check engine lights"; and no unusual transmission vibrations or sounds--just the annoying 1-2 shift. My Taurus and '83 F350 shift much better.
Has anybody else had this situation or have any ideas about the cause or a fix?
Thanks,
Ken

 

The Check engine light doesn'y have to be on for you to have pending codes,auto zone will read them for free,could be something like the Throtle position sensor or one of the 10 other trans sensors. it would'nt hurt to check.

 

You may want to try replacing the vss sensor in the rear end. They are cheap and easy to replace and can cause some unsual shift problems.
Dave

 

Put a code reader on it today--no codes are stored. Local parts house guy (who is also a mechanic) says he has never seen a bad VSS on OBD II equipped vehicles that failed to register a trouble code. He thinks maybe the computer was not reprogrammed to match the characteristics of the rebuilt transmission.
Any thoughts?
Ken

 

Mine acted sort of like that. the 1-2 shift was late and hard then the2-3-4 were so fast it seamed like one shift.but when I would get on it,like getting on the freeway,when it went to shift from 1 to 2 it would like shift into neutral,and the engine would rev.as soon as i let off the gas and the rpms come down it would catch in gear. I thought the worst,but it turned out to be the Throttle possition sensor output was low,so the PCM thought I was at idle and didn't want to shift the tranny.I replaced it and all has been perfect for 20,000 miles. I'm no trans expert so wait for some more oppinions.Have you tried pulling the shifter down in low and runing through the gears a few times manualy with the shifter?

 

Thanks, I'll give it a try! Wonder what the TPS output voltage range should be? I may try to measure it with my voltmeter to see if it has a smooth, variable response and what the range is. I had one on an '87 Chevy that had a open spot right about mid-throttle position but it caused backfires and a check engine light. Maybe the Ranger has a bad spot at a very low throttle position. I'll let you know if I find anything. Thanks,
Ken

 

From the front, the wire on the passenger side is the ref-volts wire.with key on it should have 5.0 volts.the one on the right is the ground and the middle is the TP signal wire.with the connector plugged in, prob the back sied of it , left wire 5.0v,then with your meter ground to the right wire and pos. to the middle,you should get 0.5 to 1.0 v ,then open the throttle to wide open and the volts should increase smoothly to 4.0 to 5.0v . also check the resistanceof the TPS. unplug it and check resistance between the left terminal and middle one.at full closed it should read 3.0 to 4.0K ohms,open the throttle slowly and the ohms should decrease smoothly to 350 ohms.any deviations could mean a worn or damaged TPS.

 

Checked out the TPS today: Reference voltage 5.2 V, TPS Center pin voltage 0.8 V @ throttle closed and 4.6 V @ throttle wide open, smooth change throughout range, i.e., no glitches or flat spots. Not bad? I'm still at a loss as to why it shifts so strangely. Any other ideas? Put the code reader on it again today-- no stored codes and no intermittent codes while driving. Thanks, Ken

 

Your TPS checks out.maybe the vaccum modulator valve is going out?

 

Thanks for the tip. I didn't know these new transmissions still used a vacuum modulator valve. I'll check on it when I get a chance.
Ken