front axle spline counts and corresponding years, identifying an axle (3 Viewers)

[1911]

So ended up just pulling the diff and counting teeth. its not 4.11 so now im really pissed at the PO as nothing about what he claimed it to be is correct. its a pre 79 not an 85, and its 3.7 not 4.11. which is strange no? shouldn't the pre 79 have 4.11 in it? to confirm, 4.11 would have 10 teeth on the pinion yeah? this one has 9.

To get the 3.70 ratio of the '79 and up FJ40, Toyota used a pinion gear with 10 teeth and a ring gear with 37 teeth, which is why the ratio is exactly 3.70, not the 3.73 that lots of guys are used to with detroit-made diffs. So if your pinion has 9 teeth, it is not 3.70, but most likely a 4.11.

It could be argued that the 10-tooth pinion is stronger than the 9-tooth pinion because the diameter is necessarily larger, but the difference is not much.

 

[calen]

To get the 3.70 ratio of the '79 and up FJ40, Toyota used a pinion gear with 10 teeth and a ring gear with 37 teeth, which is why the ratio is exactly 3.70, not the 3.73 that lots of guys are used to with detroit-made diffs. So if your pinion has 9 teeth, it is not 3.70, but most likely a 4.11.

It could be argued that the 10-tooth pinion is stronger than the 9-tooth pinion because the diameter is necessarily larger, but the difference is not much.

sorry, I mis-typed earlier. my current on the bench diff has 10 teeth making it 3.7. getting the gearing correct is not my biggest concern though as I have one diff on the bench that is 3.7 and one diff currently running in the car that im as certain as the PO saying it is 4.11 (its an 82 Australian hj47 troopy). so either way when it comes down to install time I will have a diff that matches and works.

my real concern is what route to go now, continue rebuilding this axle with the weaker 11mm stud steering arms or abandon it and start looking for 40/60 knuckles with discs. how much weaker are the small pattern stud arms?

 

[1911]

my real concern is what route to go now, continue rebuilding this axle with the weaker 11mm stud steering arms or abandon it and start looking for 40/60 knuckles with discs. how much weaker are the small pattern stud arms?

What is your anticipated use for this Cruiser? If it is just driving it for fun, use on dirt/fire roads, camping, etc. then the small-pattern arms are probably fine. If you're going to do some more aggressive wheeling with larger tires, then I'd want the larger-pattern arms.