Transmission help 99 Ram

Here's the problem. Reverse is slipping when you apply the throttle. It will pull itself from idle on the level on an incline it slips. Trans was rebuilt ,but now has about 40,000 miles on it. Quality parts used. There is no problem with the forward gears, firm shifts. Does this sound like a band adjustment? Fluid is full and bright red no smell. Thoughts/suggestions. A- 518 /46Re behind a 5.2.

From 20 mph in Drive, shift it to 1 and see if there is deceleration braking...if none or little, could be rear band adjustment. If deceleration braking is good, could be the OD direct clutch.

Rear servo could’ve popped out or bolt come loose. I’ve had one broke the ear off, no reverse at all.

Thanks. That gives a few things to check.

So I did the 20 mph shift it has some deceleration ,but not as much as I would expect. I do know the OD clutches where replaced because the guy that rebuilt the trans had to borrow a tool to get the OD apart.