Was wondering if anyone had experience with a broken 3rd 4th shifting fork. Ive already taken apart the tranny and identified it broke (not to mention i lost 3rd and 4th gear) but before it broke/i lose those gears i had grinding and trouble getting into 4th gear. i was wondering if work synchros could have caused the break or if those were unrelated. im going to check if the synchros are work this weekend, but id rather not have to rebuid the tranny if i dont have to and could just replace the fork.

 

I'd check the bearings & bushings in the vicinity of that gear closely for wear or slop, which could possibly cause the shifter fork issue.

 

HOLD IT RITE THERE!!! The first thing you should do, if you have the tranny still apart, is check the width of the input shaft bearing or see if any spacers are added to the ISB and worn out. Many times, if the ISB, if not the input shaft housing mount is worn out or if the bearing had ever been replaced before, twas the rong size bearing put back in, it can cause 3/4 shift problems. Ask me how I know!

 

The ISB was good but the output shaft bearing was bad, thanks for the reply, im going to make another thread because i ran into some other problems (in my own negligance and inexperience with working on transmissions i forgot to take off a snap ring and broke the teeth on the synchro for 3rd but not the brass part the part attached to third) im having trouble finding a replacememnt gear for 3rd that has the same amount of teeth, all the ones im finding have 30 teeth and the one i have has 39 which is weird. its a 1998 dodge 1500 with a nv3500 for sure but maybe its the first generation of the nv3500, whichever has the 2 piece synchros for 1st/2nd. any info on that would be greatly appreciated.