a4ld tranny issue

[xyj6p9k4]

I have a 94 ranger with a 4.0L. Noticed today driving that when the transmission needs to down shift from overdrive it bucks and doesn't seem to shift untill I really press on the throttle. Then it shifts in to 3rd I believe. Possibly 3-4 shift solenoid. Does this one have one. Up shifts go smooth it seems. Still seems like it misses 4th. When the transmission is dropped into drive possition, from overdrive at 60 mph it goes from under 2000rpm to over 3000rpm. It really screams in "D" . I have not had this truck long and have not even gone under to see the tranny yet. I am a diesel engine technician, so please don't be afraid to give complicated advice. No engine light comes on. Just replaced MAF sensor. It was causing engine light to come on, and I thought that it was related but no. If this trany has a soneloid, what are the specs and how do I test. I am very comfortable with electronic troubleshooting. thanks to anybody who has any Ideas. I never noticed the problem until it started to give a little kick back, buck feel.

 

[BrooklynBay]

Welcome to this forum! Your A4LD has a 3-4 shift, and TCC solenoid. I would recommend that you adjust the bands, kick down cable, and check the vacuum line going to the modulator for signs of leaking ATF. A new filter with fluid would be a good idea to replace if they haven't been replaced in about 30k miles.

 

[xyj6p9k4]

Found a wiring diagram and some time to look and my own vehicle for a change. The coil for the 3-4 solenoid is breaking down when hot. It doesn't create a fault code because it doesn't happen lomg enough. When it doesn't shift into 4th the load demand increases so quickly the ecm forgets about that and it kicks into 3rd is my understanding when down shifting on a hill. I also heard a backfire today because when it shorts out it robs the 12volt power supply to the injectors and so on. It measured 24 ohms when cold and 6 when hot. Not hot, hot. New solenoid on order. Hopefully this fixes it.

 

[BrooklynBay]

This is the first time I've heard of the resistance on that solenoid change when it warms up. The insulation on the wiring is probably shot, and shorts as the wires expand. I would suggest that you replace both solenoids while you are doing this.