i can manually shift it to 1 and to but it dose not have a third gear just PRND12

 

If you shift it from 1st to 2nd and then to "D" you should feel it shift to 3rd. This is one way of making sure you are feeling all 3 shifts. If by chance the rear end is really geared low and your not feeling 1st to 2nd this will prove what gear your getting to. Has the kick down cable been set correct?

 

I can feel 1st and 2nd just don't feel anything the tach don't jump or the engine does not change like it should when it shifts and ya I have the kick down cable hooked up right and working good

 

Well something is not hooked up correct if the trany is not shifting to 3rd gear. The rear diff has nothing to do with the trany shifting. I know there are a few different types of kick down cables. They are not all adjusted the same. It has got to be something that is not hooked up correctly if more than 1 trany has done the same thing.

 

I have another kd cable I will swap in and see if anything also on the old one on wot the cable ia fully extended is that how its soposed to be and also should I hook up the modulator to the.vac on the.carb or the manifold?

 

Hook vacuum to manifold vacuum on the carb (my preference).

What year is the transmission?

Sounds like the modulator valve, either bad or needs adjusted. Could be the governor.

 

Not sure on the year of it but it was rebuilt less then a year ago and how would I go about adjusting the modulator valve?

 

Google search (or You Tube) "adjust TH350 modulator valve" and "adjust TH350 governor" should be some step by step videos and write ups.

 

I think it is a blown diaphragm in your TV modulator valve if you have the vacuum line right and the kickdown correct. Check for slack in the kickdown cable also when you WOT the butterfly.

 

i think it might have been a faulty kickdown cable, i took it for a long drive down the freeway and when i got home and after letting it set i noticed that i lost almost all my fluid it seems the kickdown cable broke where it bolts to the trans so im going to get a new one and see if that does any good also going to replace the modulator valve