96 Explorer 4R55E automatic "slippage"

[Soultare]

So I've been trying to nail this problem down for a while now 6+ months.

So I bought this truck from my aunt knowing it didn't have O.D. (238,000 miles and a lot of mountain trips) and figured it might be a fun project to rip apart the trans and see what's going on. Long story short I have not gotten to that yet because another issue arose. My transmission has been losing its gears when I come to a complete stop and sometimes wont even go into 2nd for about a second maybe even three. It's been kinda intermittent for awhile then I noticed it seemed to only happen when I drove it a good enough distance to warm it up.

So despite my better judgement(Being taught that after 150k if the fluid hasn't been changed it wasn't a good idea) I decided to drop the pan,flush the fluid, and ohm out the shift solenoids. I measured about 27ohms on the shift solenoids. So kinda left it at that and the problem has just slowly gotten worse.

So far I've changed the fluid about 3 times as I've been in the pan that many times, I've replaced the filter and the valve body gaskets and the problem hasn't gotten worse and there for while actually got a lot better.

Long story short a friend of my then suggested to just try shifting it manually until it's in drive. I almost blew my brains out cause I never even thought to try it, and what's worse it works flawlessly when I'm manually shifting up until it goes to shift into 3rd and itll hesitate and high rev for a split second then go into gear. But what's od I when the truck gets into gear I never have a problem until it wants to shift, I could hammer the pedal in 1 and kick gravel and spin tires but it's getting into gears that's the problem.

 

[974X4BLACKSPORT]

Sounds like low hyd. pressure. As is the first step when diagnosing most transmission problems, a running hydraulic pressure check is needed. I am also assuming it is NOT low on fluid.

 

[96eb96]

So I've been trying to nail this problem down for a while now 6+ months.

So I bought this truck from my aunt knowing it didn't have O.D. (238,000 miles and a lot of mountain trips) and figured it might be a fun project to rip apart the trans and see what's going on. Long story short I have not gotten to that yet because another issue arose. My transmission has been losing its gears when I come to a complete stop and sometimes wont even go into 2nd for about a second maybe even three. It's been kinda intermittent for awhile then I noticed it seemed to only happen when I drove it a good enough distance to warm it up.

So despite my better judgement(Being taught that after 150k if the fluid hasn't been changed it wasn't a good idea) I decided to drop the pan,flush the fluid, and ohm out the shift solenoids. I measured about 27ohms on the shift solenoids. So kinda left it at that and the problem has just slowly gotten worse.

So far I've changed the fluid about 3 times as I've been in the pan that many times, I've replaced the filter and the valve body gaskets and the problem hasn't gotten worse and there for while actually got a lot better.

Long story short a friend of my then suggested to just try shifting it manually until it's in drive. I almost blew my brains out cause I never even thought to try it, and what's worse it works flawlessly when I'm manually shifting up until it goes to shift into 3rd and itll hesitate and high rev for a split second then go into gear. But what's od I when the truck gets into gear I never have a problem until it wants to shift, I could hammer the pedal in 1 and kick gravel and spin tires but it's getting into gears that's the problem.

Could be the servos wearing out. I think you can remove them, they are by the cats.

 

[Soultare]

Could be the servos wearing out. I think you can remove them, they are by the cats.

Yea I will say the fluid isn't low, I've checked it multiple times and it doesn't seem to change any and it's still bright red, I thought that to I just can't figure where I'm not getting pressure

 

[96eb96]

Yea I will say the fluid isn't low, I've checked it multiple times and it doesn't seem to change any and it's still bright red, I thought that to I just can't figure where I'm not getting pressure

You could also download a free app called forscan, run it on your PC. Get a cheap OBD adapter (BAFX, or something that runs Forscan).

You have access to almost as many trans parameters as a 2019 Explorer!

You can look at EPC pressure, rpm differences, shift command, etc. But at this mileage (a very good run, and proof the 95-96 4R55Es are pretty stout) something is likely warn down. You may get away with new servos, the rubber may have deteriorated.

 

[Soultare]

You could also download a free app called forscan, run it on your PC. Get a cheap OBD adapter (BAFX, or something that runs Forscan).

You have access to almost as many trans parameters as a 2019 Explorer!

You can look at EPC pressure, rpm differences, shift command, etc. But at this mileage (a very good run, and proof the 95-96 4R55Es are pretty stout) something is likely warn down. You may get away with new servos, the rubber may have deteriorated.

Okay I'll have to look into that when I get the chance, I'm currently getting another car this week, I will post some results when I get the chance