Intermittent no reverse

[91 PBP 5079]

Hello Eveyone
Anybody have any experience with this problem and what was the outcome.

96 D1 180k on truck 110K on automatic transmission. Has intermittent no reverse. Seems to only do it after going forward for a bit. Doesn't seem to do it when backing out of driveway after setting stoped with engine off.
Fluid is good and at proper level. Does not appear to be linkage related. Has engine brakeing in 1st gear. I think it is the reverse lockout valve hanging up. If so I am not to worried about.
I am just wondering if the trany is ready to go completely crap on the thing.
The head gaskets are starting to weep coolant.
The cats are rattling.
It has 2 bad O2 sensors.
Engine oil pump is questionable.
So I am trying to figure out if I will fix it or try to find something else.
Thanks for any help.
PS
Please contribute to Dweb it is worth it:bigok:

 

[tomelroy]

what happened with the trans? I am having the same problem.

 

[91 PBP 5079]

I am still driving it this way.
Ther is another symptom that seems to happen with this reverse problem.
It down shifts to 1st gear when you take off from a stand still and then shifts up normal all the way to lockup. It acts like it doesn't down shift when you stop.
The fluid is not burning and it isn't getting any worse. The rev problem seems to be getting less frequent. When it does do it I just put it into park and then reverse and it works fine.

 

[KyleT]

did you change the filter?

 

[flyfisher11]

Might be the clutches. IIRC 1st and R are the same and usually the first to go.

 

[crown14]

Try swapping the valve body and see what happens.

 

[91 PBP 5079]

I think I had the fluid level to high.
I now have it just touching the dipstick when cold and about 19mm above max cold when it is hot. It is working much better now.:banghead:

 

[syugg]

Just had the same issue with my 96 D1. Clutch pack in my auto trans was worn. Ended up having to doing a rebuild.