looking to buy an 4.7fd tranny but the LSD N3E stamp is gone... is there any way u can tell its a true 4.7fd tranny beside taking it apart? and if u gotta take it apart what do u look for? whats the teeth count for a 4.7fd?

 

4.4 final drive = If you put the trans into 1st, it takes 14.2 rotations of the mainshaft to make 1 full rotation of the diff.

4.785 final drive = If you put the trans into 1st, it takes 15.5 rotations of the mainshaft to make 1 full rotation of the diff.


Your going to have to mark the mainshaft and the inside the diff as well as the case to count the number of turns. I suggest you mark both sides of the diff just in case the diff internals shift while spinning the gears. This would throw off your readings. I don't know how likely this is to happen, but I would do it just in case.

 

A 4.7 ring gear will have 67 teeth.

 

^That means the secondary shaft pinion will have 14 teeth.