Y do I loose reverse when my c4 gets up to temp? Cold goes right in goes around the block you have to rev it to 2 grand for rev another round no rev.

 

As I understand it, reverse on a C4 requires more pressure to operate than your forward gears. Check you fluid level and if it is OK, I would suspicion the pressure pump as not generating enough pressure to tighten the reverse bands when the fluid thins down.

 

Could the rear band be out of adj

 

Could be, but by your description, it sounds like a pressure pump problem. I have an article about how to tighten your bands in the FAQ up toop under transmissions. You might give that a shot. Won't hurt anything.

 

I think the rear band was out of adj it seems better now on stands. Going to drive it today.

 

The band for reverse is shared with low (1st). As Glen mentioned, check the fluid and all the adjustments. Wouldn't be a bad idea to change the filter/fluid as well.

If you do need a rebuild, don't forget the external trans filter and synthetic fluid. An extra cooler wouldn't be bad, either. Autos don't like running anywhere near the temperature of the engine.

 

Well here is the deal...Its a new TCI but it was installed after the 1 yr warr was up..took it to the muffler shop yesterday went right into rev coming out of the garage. Had 1st 2nd no 3rd, while it was up in the air adj the vac mod. Wouldnt go into rev had to push it off the rack and still no 3rd so I guess Ill be calling tci