I have a 93 f350(cab/chassis) 4x4 with the 7.5 and 5 speed tranny. A couple weeks ago my rear end went out and i had to use 4 wheel drive to make it home(glad i had 4x4), but the shifter broke the crappy arm that bolts to the tranny and i had to manually shift the transfercase gears underneath. But now everytime i try to back my truck up with a trailer, it keeps popping out of reverse(but doesnt do it without the trailer). I have always sometimes had trouble getting it into reverse for a year.

This is the 2nd tranny i've had reverse problems with.

Anything that coulb be causing it?
It has a yr old clutch, slave cylinder, clutch master cylinder, etc..

 

Zf's are known to wear out the reverse gear synchronizer. Pretty major job but there are a few write ups on the net on how to do it.

 

As I recall you can do it with the transmission in the truck just pull the tcase adapter off

 

No, you need to remove the trans an disassemble

 

Maybe it's the 1/2 ton manual