I have a 1984 F150, 6cyl with a c-5 auto trans. I have rebuilt the carb and replaced all fuilds. I now have issues with the transmission shifting - it ran well fopr a while but lately it has gone from shifting itself to me having to shift from 1st to second and it would shift to third, Now I can only shift myself from 1st to 2nd and it never does go to third.

Anythoughts - replaced the fluid and filter already, no leaks I can see, is there a modulator or selinoid that I should be looking at or replacing or any other part before I have to send it to the transmission shop? If that is the only option I think my old boy may be finished - so if you have ideas you can help this old truck from the crusher.

Thanks,

Dave

 

Are you sure the ATF level is at full? There may have been air pockets left in the system after a drain and fill. You may need to check and add fluid several times.
Kevin