700r4?

[Speedo]

What is the most likely problem for lost reverse in a 700R4? Guy drove his truck home parked it and went out later and no reverse when he tried to back up. He checked obvious things like linkage and fluid level.

Truck is a 1983 3/4 t. with a 6.2.

Gus

 

[Greg Ducato]

Broken reaction sun shell spline will cause a loss of reverse, second and fourth gears. A blown rear planet due to heat or breakage will generally cause no reverse and a heck of a lot of noise most times. Bad reverse clutch pack usually gives months of warning before total failure. If the trans has been built recently there is an uber slim chance the plate at the rear of the valve body next to the accumulator cover could be loose and venting reverse line pressure. Any way you stack it, loss of reverse in a 700 means somebody is pulling a trans....

 

[Speedo]

Broken reaction sun shell spline will cause a loss of reverse, second and fourth gears. A blown rear planet due to heat or breakage will generally cause no reverse and a heck of a lot of noise most times. Bad reverse clutch pack usually gives months of warning before total failure. If the trans has been built recently there is an uber slim chance the plate at the rear of the valve body next to the accumulator cover could be loose and venting reverse line pressure. Any way you stack it, loss of reverse in a 700 means somebody is pulling a trans....

Thanks for the quick reply, I'll have to check with him to see if there was anything going on as an indication of pending doom. I don't think that there was anything done to the tranny recently. It's on a snowplow truck and it is snowing as I type this.

Gus