4L80 transmissiom

I have a 1995 chevy 2500 2wd with a 5.7 and 123k miles. won't go into reverese. no codes stored can any one help

Check transmission fluid. With engine running, it should be full and pink with no burnt smell. Brown or smell means transmission trouble.

fluid is ok any other suggestions

After the fluid I am afraid it's is transmission trouble. I can not think of anything outside. It must be something on the inside. Unless the shift lever is not moving but you did not say that.

Are you getting an MIL (check engine, service engine soon) light on the dash?

no no light

Okay, it looks like rebuild time, then. A solenoid failure (which can cause your issue) will set a DTC and illuminate the MIL.

can i replace the 4L80 with a 4l60

can i replace the 4L80 with a 4l60

If your vehicle came with a 4L80E, then I'd say NO. (There is no 4L80, but there is a 4L80E. However, there are both 4L60s and 4L60Es. The 4L60 with no E is also called a TH700R4).

I would also crawl underneath the vehicle and check the factory plug connections that go into the tranny. They can be easily damaged. Possibly you were doing some maintenance and bumped them? Don't do anything without disconnecting battery. My truck went into "limp-home mode" once when the ignition wire to the starter solenoid touched the exhaust and grounded. Also, and this is just my opinion: have the dealership replace the tranny with a remanufactured GM tranny; comes with three-years/36,000 mile warrantee. If I had the time, I could tell you the horror stories I had with my 4L80E rebuild. After letting some indy tranny shop (attempt) to rebuild my tranny (four times in one year), I had a remanufactured tranny put in and have 100,000 miles-plus on it. Indy shop kept saying it was something outside of the tranny causing it to burn up. Funny how the new GM tranny didn't have those same issues once installed!