I am rebuilding the front and rear differentials on my 77 FJ40 and in the process also swapping ring and pinion sets from 4.11 ratio to 3.7. I sourced two used 3.7 ratio Toyota ring and pinion sets from 4 wheel auto in Canada more than a year ago. For the first gear set I received the only difference with what I removed was the gear ratio and the change from course to fine spline on the pinion gear, for the rest the design was the same as what was installed on the 77 year model.
The second set of gears I received is from a newer Landcruiser I am not sure it was removed from a FJ40 though. The design for pinion preload uses the crush sleeve which I intend replacing with a solid spacer. The bearing seat diameters on the 3.7 pinion is the same as that of the 4.11 pinion I removed and the splines changed from coarse to fine as expected. The pinion nut diameter on the 3.7 pinion however is larger than that of the 4.11 pinion, the pitch for the old and new is both 1.5 but the outside thread diameter changed from 19.84mm on the 4.11 to 21.85mm. on the 3.7 Which model landcruiser may the 3.7 pinion originally be from? and what is the Toyota part number for the larger pinion nut and washer? Below of few pictures of the 4.11 pinion I removed and the 3.7 pinion I am installing.
OD of thread on the 3.7 ratio pinion
OD of thread on the 4.11 ratio pinion
Side by side of 3.7 pinion on LH and the 4.11 pinion on the RH
The second set of gears I received is from a newer Landcruiser I am not sure it was removed from a FJ40 though. The design for pinion preload uses the crush sleeve which I intend replacing with a solid spacer. The bearing seat diameters on the 3.7 pinion is the same as that of the 4.11 pinion I removed and the splines changed from coarse to fine as expected. The pinion nut diameter on the 3.7 pinion however is larger than that of the 4.11 pinion, the pitch for the old and new is both 1.5 but the outside thread diameter changed from 19.84mm on the 4.11 to 21.85mm. on the 3.7 Which model landcruiser may the 3.7 pinion originally be from? and what is the Toyota part number for the larger pinion nut and washer? Below of few pictures of the 4.11 pinion I removed and the 3.7 pinion I am installing.
OD of thread on the 3.7 ratio pinion
OD of thread on the 4.11 ratio pinion
Side by side of 3.7 pinion on LH and the 4.11 pinion on the RH
