Trans "stuck" in neutral

[kingkevin8]

My friend has a 94 aerostar that was shifting fine the other day, but today he started it and the trans wouldn't engage in R or D until he gave it gas, then it would sort of slam in gear/half way catch into gear. Any ideas?

[mmerlinn]

Originally Posted by kingkevin8

My friend has a 94 aerostar that was shifting fine the other day, but today he started it and the trans wouldn't engage in R or D until he gave it gas, then it would sort of slam in gear/half way catch into gear. Any ideas?

Hanging valve in valve body?

When was the last time you did a transmission flush? Quite possible something in the oil got stuck in a valve in the valve body. These valve bodies can be finicky. They have aluminum valves in an aluminum housing. Does not take much for a valve to hang.

Another possibility is that something broke in the gear train. These transmissions had a habit of breaking the sprag race on the overdrive planet. No idea if that would cause your symptoms though.

Not sure whether/if the bands control R and D, but if one does, it could be a worn out band. Revving the engine to move will just cause more damage to the drum the band rides on.

Does your oil smell burnt? If so, rebuild your transmission. If it is not bright red, flush your system. If you see metal chunks in the pan when you flush, rebuild the transmission.

Another possibility is worn pump causing low pressure. Revving destroys the pump faster.

Valve body has two solenoids. They often go bad. Don't know if that would cause your symptoms.

There is a tiny filter in the valve body. If plugged, you will have weird problems.

[kingkevin8]

Thank you for your ideas. It just seems really weird that it will only go into gear when he gives it gas. I just told him to drive up the street and back to see if it goes away, but it didn't, so I told him not to drive it at all, and the first cheap thing to do is a trans fluid change. It does seem kind of similar to my old Saturn I had. When I would put my Saturn into R it would take a while, then slam into gear, yet similar to the vans problem, it seems to be a lot different.

I've never worked on an Aerostar until this one, so If you have any tips I would appreciate them.

[mmerlinn]

I have never worked on my Aerostar, so don't have any tips for you. Neither have I ever fixed a transmission of any kind.