Any idea on this problem with 4L80 transmission?

[Intercooler]

Family member with a Z-71 wants me to come over to have a look since it has no reverse. Any thoughts? I am no trans expert but can hopefully tell if it is smoked Could it be something simple?

 

[broke1]

Doubt its something simple and I doubt its a 4l80 unless its 3/4 ton or above.I know the last body style GM's didnt have 4l80's unless the were 3/4 ton up.

 

[Intercooler]

I found out they are 4L60's. Just checked it out: I checked it out and the fluid was at the right level, not burnt smelling and looked like new. I had all the gears except reverse. When I put it in reverse you can kind of hear a little change in the sound of the trans/converter but even giving it some pedal it just wouldn't move. Any thoughts?

 

[blackplague]

Does it have 2nd gear?

It is Very common for the sun shell to break the splines off. When this happens, you get no reverse and no 2nd.

What year is this truck?

 

[Intercooler]

It is a 1997. After asking more questions a thud was heard before this happened. I am pretty sure it has second but reverse is gone. I think the thud was the Sun-Shell. Does this spell full rebuild or is it pretty simple? Anyone make a 4340 piece?

 

[blackplague]

When the sun shell breaks

It has to come apart. They have a new shell out on the market that is real nice and is the same price as a new stocker, the new shell is called "The Beast" and it comes from a company called SPX. It's a real heavy duty part.

Your No Reverse situation is not a electrical problem, it's a base trans problem. Even if you pulled the electrical connector off, it would still have reverse in reverse range.

 

[Intercooler]

I am ordering one of The Beast shells. It could also have been the boost-valve but after hearing about the pop I think it is the Sun-Shell.