A518 Transmission, no reverse when hot

[jrlegacy23]

I just got an overdrive trans for 1968 Barracuda. It is a 1993 Dodge A518 (46RH) transmission that was pulled from a half ton van. The tranny was working fine and then started losing reverse when it is hot. When the engine is cold it operates fine; but once up to temp, the reverse in the tranny doesn't work at all.
Any tranny guys out there have an idea of what may be wrong?

 

[jas0162]

Does it still shift into direct ok?

 

[motorpirate]

I just got an overdrive trans for 1968 Barracuda. It is a 1993 Dodge A518 (46RH) transmission that was pulled from a half ton van. The tranny was working fine and then started losing reverse when it is hot. When the engine is cold it operates fine; but once up to temp, the reverse in the tranny doesn't work at all.
Any tranny guys out there have an idea of what may be wrong?

Broken snap ring in the OD clutch can do that if all the snap ring pieces didn't fall out yet.

 

[jrlegacy23]

Does it still shift into direct ok?

Yes, everything worked as it should. Once the tranny warmed up, reverse was like neutral.

 

[jrlegacy23]

Broken snap ring in the OD clutch can do that if all the snap ring pieces didn't fall out yet.

Would those pieces be in the pan when I pull it? I plan on pulling it off tomorrow, just want to know what to look for.

 

[CudaFactHackJob]

Does it have low one engine braking?

 

[jrlegacy23]

Does it have low one engine braking?

I have no idea. LOL. He was driving it, that happened and he replaced it. It cam out of a 1993 Dodge 250 Conversion Van (5 lug wheels)

 

[CudaFactHackJob]

The back band could have a leaky servo.

 

[jrlegacy23]

The back band could have a leaky servo.

That's what I was thinking. I have a friend that will go through it and see.

 

[motorpirate]

Would those pieces be in the pan when I pull it? I plan on pulling it off tomorrow, just want to know what to look for.

Yea, piled up on top of the valve body at the rear.

 

[TrailBeast]

Before the valve body is pulled take a good look at the reverse band servo and the adjustment for the rear band.
It could be way out of adjustment, have a folded over seal or even the servo itself cracked.
What is described by "works when cold" tells us that thicker fluid makes it work, but hot fluid is thinner and can get past the servo.

That servo can break in all kinds of different ways and cause what is happening.