I am rebuilding my front axle and i didn't keep track of my knuckle bearing preload shims. Is there a ghetto way to figure out the thickness wo the special tool? I know how to check the preload with the scale, but how thick on top and bottom? Are the thicknesses supposed to be the same? This axle is for a turbo truck that will be driven on the street so i want to be as anal as possible. Thanks

 

As long as you put the shims in the same order top and bottom you should be ok, thickest one closest to the knuckle working your way to the steering arm, or trunion cap. Here is a diagram that should give you the thickness and how many to use. Hope it helps.

 

Look on 4crawlers website he has a general rule of thumb to use.

:wabbit2:

 

From 4Crawler's site

When reinstalling the steering arms and lower knuckle bearing retainers, be sure to install the appropriate shims.

* I think mine were bone stock when I took them apart and there were no shims.
* The rebuild kit came with a huge stack of shims. I at first put the knuckle back together w/o shims and found it was overly tight.
* After asking around, the consensus seems to say 0.40mm (or 0.040" I don't know what units are used ) of shims is the right amount.
* The factory manual describes a bearing drag measurement technique if you prefer:
o Use a fish scale to pull on the steering arm until the break-free pull is 7-13 lbs.
o Do this without the knuckle wiper seals installed, just the knuckle bearings.
* Be sure to pack the knuckle bearings before installing them.

 

Cool, good info. I just talked to a guy at MC and he said to start with the .040 shim on the bottom to get the spacing right so the axle rides in the center of the oil seal, then add or subtract shims from the top as necessary to preload the bearings, so when a pull scale is hooked up to the tie rod hole in the steering arm, it takes from 7-15 pounds of force to move the knuckle. MC guy said he likes his on the tight side because he runs the bigger tires, but im just running 31s so i think ill start with 14lbs with the hopes that theyll break into about 10lbs.