WC 12 transmission swap

[Tim O'Kelley]

Good morning. Anyone know if any of the later synchronized tranny's will work with the 1/2 ton WC's. Thanks. Tim

[Daryl in Oz]

Not without other changes

The synchro NP420 has a different mounting pattern to the non-synchro trans and the bore in the clutch housing is different . Overall length of the gearbox is close enough to work. You will need to either change the clutch housing to a later type to match the bolt pattern and front bearing retainer, or modify your existing housing to suit. Either way you have to remove the clutch housing unless you want to cheat - not advised but will work. You also need to replace the clutch plate with one that will suit the new trans. If you choose to modify your original housing, you first need to reduce the diameter of the gearbox front bearing retainer (about .25" if memory serves) then when you offer up the new box you will find one mounting bolt goes in OK. You then mark what needs to be changed on the housing, in some existing threaded holes, you need to insert a filler stud and when you drill the new hole it will partially overlap the filler stud. I think from memory I was able to elongate one of the gearbox mounting holes to pick up another existing hole, but you get the idea.