I am rebuilding my 400 motor in my 1980 F-350 4x4. When I removed the motor, I reached down to the tranny input shaft and noticed that it felt pretty sloppy in the side to side lateral movement.... end play appeared to be a little much as well, at least by eye...

I now have the tranny out of the truck (it was leaking as well) I want to take care of what I have to so the refreshed motor won't rip it up... I have the Ford service manual which covers the NP435 pretty well, but was wandering what any of your experiences are in looking for worn parts with sloppy input shaft condition... (worn case bearings, pilot bearings???)

Also, not having cracked a tranny case before (I am reasonably mechanically capable, always learning) I have read where some beginners have trouble after removing the top plate and shift fork assembly...

Thanks for any helpful experiences....

 

The input shaft SHOULD have some side to side slop in it. The end play should be .007 to .017". Now if your input shaft moves enough to touch the side of the housing, then you have problems. If you do decide to rebuild it, I recommend getting a kit from Bronco Graveyard. I bought a master kit for $165 and it solved all my noise and leak problems. It comes with all new bearings and seals to rebuld it. I had never rebuild a tranny before either, but I took my time and it wasn't that difficult. It took me the better part of two days to do it, but that was mostly due to my lack of the proper pullers to get the old bearings and races out (i cheated and used a dremel tool and cut some of them out)
These trannys are VERY strong, mine had 186,000 mi of heavy towing use and except for the unsyncronized 1st gear, all the gears were in terrific shape. I shifts like new and makes no noise where before the shifter would rattle and the tranny would growl in 3rd and 4th gear. Turned out to just be the bearings, although when I took them out, there were no obvious signs of wear or damage. If all yours is doing is leaking at the input and output shaft, then I would just replace those two seals and be done with it.
Hope this helps.

 

Dave,

Thanks for your reply. You have answered my biggest question about the shaft play and unfortunately it is enough to touch the housing... I was extra concerned (forgot to mention) because of a chattering clutch and rough clutch engagement in low RPMs... after clutch removal, you could see chatter marks along one area of the flywheel indicating the clutch and flywheel weren't meeting in the same plane initially... Again, since I am rebuilding motor and replacing clutch, I don't want a sloppy shaft to cause the same issues after putting it all back together