Used 4.1 front/rear from 77FJ40

[MJM]

Location

United States

Used 4.1 diffs. from a 77FJ40, the truck had 120k and was dare I say never off road. Never leaked truck was from the South West. $100 for the pair located near Cleveland, OH

THanks
MJM

 

[Sputnik40]

Any chance the 77 is close enough to 78 production year and these are fine spline diffs? If so, I will take them.

 

[MJM]

Not sure about fine spline

I do know that I repalced them with 3.7s from an 80FJ40 to have a better on road driver. I am not sure about fine splines or not. Let me know.
MJM

 

[MJM]

Production Year

Production date of the truck was 11/76

 

[Sputnik40]

Production date of the truck was 11/76

Nope - most likely course spline. You can check by pulling the driveshaft flange off and counting the splines on the pinion. I think it's 27 for fine spline.

 

[Fast Eddy]

Nope - most likely course spline. You can check by pulling the driveshaft flange off and counting the splines on the pinion. I think it's 27 for fine spline.

If he swapped directly with 3.70s without changing axles they would be fine spline.

 

[Fearnofish!]

I'm next in line

I'm next in line if they are fine spline.