Ok I have a 1996 blazer the only gears I have are 1st and 3rd no reverse. The gears I have are strong no slipping or anything. Please help?

 

The reaction sun shell has broken in the transmission. The transmission needs to be removed & the sun shell replaced.

 

can i just replace the reaction sun shell or do i have to do a complete rebuild?

 

You can replace just the sun shell, but you have to gut the transmission to do it. A close inspection of all of the bands/clutches should be done to determine their remaining life. It would suck to replace the sun shell, then have a clutch pack go out a short while after.

If/when you get to replacing the sun shell, get "The Beast" sun shell. It is much stronger than stock.

 

ok thank you i will keep you posted.