Checking the driveline-diff angle on a Fj40

[LEO5651]

Checking driveline-diff angle on an FJ40, what are the steps for a FJ40. I am not sure but is from the
E brake flat face area with a degree gauge then the drive line and then the flat of the diff pinon? All done with the FJ40 on level ground or are we missing a step?

 

[1911]

Checking driveline-diff angle on an FJ40, what are the steps for a FJ40. I am not sure but is from the
E brake flat face area with a degree gauge then the drive line and then the flat of the diff pinon? All done with the FJ40 on level ground or are we missing a step?

View attachment 1594495

Yes. Flat surface more important than level. You want the angle between 1 and 2 equal and opposite to the angle between 2 and 3.

Here is a photo of mine. The angles are not exactly equal, but within a degree or two is acceptable:

rear drive shaft geometry

• 1911
• Dec 19, 2017

 

[LEO5651]

So only the three points (E-Brake, D/S, pinon face on diff) are needed to get the difference in degrees on a 40. Did you do yours already , it looks pretty good on the angles. We have 3* at the e brake 10* on the driveshaft, 4* on the diff.
Thanks

 

[1911]

So only the three points (E-Brake, D/S, pinon face on diff) are needed to get the difference in degrees on a 40.

Yes.

Did you do yours already , it looks pretty good on the angles. We have 3* at the e brake 10* on the driveshaft, 4* on the diff.
Thanks

Yes, that photo was after a 3" lift and appropriate shims. I still have a slight vibration at about 35-40 mph; to get rid of it I will need to go with a double-cardan drive shaft, but the vibration is so minor that it doesn't really bother me.

You should be fine with 3 and 4* u-joint working angles.

 

[LEO5651]

Looks as we may need a 3* shims. We just put in a set of used springs that we bought that have a 2.5 inch lift but enough to change the D/S angle to the diff so I think we will be good. Thank you.