700-R4 reverse but no forward - Help! Crosley! (or anyone-)

My Brother's '89 Astro Van is stuck with no forward gears, but will go in reverse. Is there anything he might be able to do in the gravel road at his house in the woods, like a stuck shift valve or maybe a computer plug in that he could check before going to AAMCO or the junk yard with it?
It has been sort of progressively getting slow to start moving after putting into in to gear I think if that helps.

Yea, I know a '89 Astro is off topic but the trans is in a lot of old cars so an answer is going to be relevant to and besides, my Bro needs some help, and he's my Bro!

Thanks in advance.

 

time to swap that trans. had that same prob. also might wanna try changing the fluid.

 

Sounds like the s clip fell off where the linkage hooks to the plunger in the valve body

 

Crosley replaced a forward sprag in mine once. Not sure if there's a reverse sprag, too but it might be a possibility.

 

Is that visible with just the pan off?
Can it be reattached without taking the valve body apart?

 

Reverse is OK, it's forward that's no va.

 

Time for a rebuild or new trans. Did it make noise right before failing? Don't go to AAMCO unless they can give a fixed price. A rebuild on a 700r-4 with r&r should be under $2K. If a shop tells you they will not give an estimate before a teardown, it will be over $3K.....

 

when they start doing that, its time to come out.

check fluid condition.

if he's brave he could pull the pan and see what kind of stuff is in there (like clutch bits, etc).

 

I rode in it a couple of months ago and it was hesitating before upshifting, but didn't seem to be slipping like worn out clutches might do.
I don't think it made noise, just hesitated before starting to pull.

 

I bought three of them in the past year. (three cars) Good luck!

 

Thanks for the link, He and the Astro are in Gr*** Valley CA North of Auburn out a dirt road in the woods.

 

Yes it is, s clip will probally be laying in the pan if thats what it is