No reverse or drive
help please if you can
Did you try replacing the vacuum modulator, and/or checking the vacuum line from the engine compartment to the modulator? I had a very similar problem with my 1967 F-100 original tranny. It wouldn't shift into 3rd, and 1st to 2nd was erratic. It acted just like there was some major mechanical problem with the gears or there was no fluid. I found out that the tranny's vacuum modulator rubber hose to steel pipe had fallen off in the engine compartment area. Hooked it back up to the pipe and all was well again. It must have rattled itself off, then again all my vacuum lines and rubber parts in general all needed replacing.


