RFB
97 FZJ80 LIFTED SC DUAL BATTERIES,37s
Instead of adding shims under the pinion head I decided to put the shims under the inner pinion race (most diffs are built this way, save for the 8” bread of Toyota gears). This means the shims for pinion depth push the pinion bearings apart ( by approximately .072”), doing this causes other issues I’ll go over shortly… These new Toyota gears (100 series) are 2 cut gears (face hobbed) which cause the pattern to show up very differently than traditional 5 cut gears (face milled).
If you setup diffs I found a great link that explains the movement of 2 cut gears that I have stashed in my notes…
2 cut gear’s pattern shows up slanted as opposed to the nice ellipses that 5 cut gears display. As mentioned above this is .072” of shim under the inner pinion race.
Drive side…
send me mine or ill come pick it up should be in your hood in a couple weeks.
Coast side…
Since I didn’t put the shims under the pinion head it created a problem with the solid pinion spacer, the solid spacer was hitting a register on the pinion shaft instead of seating against the inner pinion bearing. I wound up adding shims to both the bottom and the top of the spacer in order to finally reach the proper preload. The bad part is it took .127” (which is slightly more than 1/8”) of shim to get it to preload properly (5 in-lbs @ 150 ft-lbs of pinion nut torque)…
You can see the outer pinion bearing register the spacer was hitting in the center of the picture…
Aside from .127” being a lot of shims to wear out, I decided that I wanted a solid spacer that didn’t need any shim at all. At first I was going to have one made then found that the old 4 cylinder solid pinion spacer would be perfect so I ordered 2 and went to “turning”. Machined .289 off the bottom of the spacer which should leave about a 10 thou gap between the pinion shaft register and the spacer chamfer, the rest of the length was taken off the top of the spacer. Then took two quick sanding sessions (400 grit) on a granite block to get the 5 in-lbs of preload I was looking for…
Pinion bearing spacers (left to right) factory crush sleeve, V6 spacer along with .127”of shims, 4 cylinder spacer (machined; no shims needed), and factory 4 cylinder spacer.
Last mod will be to the factory oil baffle, I am going to open the ID so that it has almost the same gap as the stock crush sleeve.
Getting off of diffs for a minute made a new tie-rod (4130) with EMF GM 1 ton rod ends, they dwarf the factory size FJ80 rod ends… (And yes the old tie-rod is already sold…)