97 5R55E No reverse, good line pressure.

[HahnsB2]

I'm sure no one remembers me as it's been probably a decade since I last posted here but anyways.

Girlfriend has a 97 Explorer 4.0 SOHC 4x4. In 2015 I took it to the minute mart and when I got home and put it in reverse I got a "clang" sound and it had no reverse. Research led me to believe the reverse band broke. Ended up grabbing a junkyard tranny and swapping it in. After which I told myself I would never do that again, I'm sure some of you guys like these 2nd gen Explorers but I think they're a nightmare to work on.

Anyways, here we are maybe 25k miles later, same thing happened again, in our driveway no less. Did some more research this time and found it may be a blown valve body gasket or bad reverse servo o-rings as well. I hooked a pressure gauge to check the line pressure and on cold start I'm seeing about 100PSI in Park, Drive, ect, and 200PSI in Reverse, which sounds like plenty to me and leads me to believe it's not a gasket or o-ring causing the problem.

For fun I just took the pan off the original bad tranny and pulled the reverse servo and I sure can't find the tab for the reverse band with a screwdriver, which tells me my original diagnosis was correct?

I will not be sad to see this rig go, I just would rather it be a cheap fix though. Any thoughts?

 

[JK080]

The pressures are sufficient but that still cannot rule out a leak in the reverse circuit, you are just reading the line pressure. The only thing you can do is go look for the blown gaskets or servo problems, this will also let you inspect what you can see with the band just like you did with your other transmission.

 

[974X4BLACKSPORT]

If you have no engine braking when in the shifter is placed in "1" or (low), then the "low/reverse" band is broken. Place the shifter in "1" and go for a drive, get to about 5-10 mph and let off the accelerator, if the vehicle just coasts instead of rapidly slowing down, this indicates the "low/reverse" band is not "holding".