99 ranger 3.0 tranny problems

[stolen 5.0]

I have a 1999 ranger xlt 3.0 4x4 with an automatic.

It's all stock, I just daily drive it. It has 135k on it and I don't know the service records on the tranny, i've just been driving it since 85k. I've always checked the tranny fluid and it's been fine and clean. Since I didn't know the previous records I was scared to do a flush and filter.

I put it in reverse today and it does not engage into reverse. 1st, 2nd, and drive work fine. tranny fluid is at a good level and clean and there are no leaks. I would think the reverse band died, but 1st gear still works fine and it gave me no symptoms of failure before hand. I always baby this thing and never beat it it. Is there an electrical problem or a smart part that is not letting it engage into reverse or is my tranny screwed? any help appreciated.
thanks
jason

 

[BrooklynBay]

It might be possible that the tip of the low/reverse servo is chipped, and is creating this problem, but from the way you are describing the symptoms, I think it might be a stuck reverse modulation valve in the valve body or a broken shift fork in the transfer case.

 

[stolen 5.0]

I've noticed my shift work in the transfer case sometimes not dis engaging properly when shifting out of 4wd. Maybe that is the problem. I was not aware that is was linked to reverse gear.