Topic: shims?.. newbie question

[slimlaudin]

  Iam hearing about shims on knuckles..im switching to histeer and i got a rebuild kit.when putting one of me hist. Arms on i had no shims there? Should there of been?..also welding truss on axle..steps to not warp?

Thanks a bunch u guys

[lone walker]

All axles I know of have shims from Toyota, unless previous owner took them out, but for what reason??... I can be wrong, most axle so far, I haven't seen an axle without them. There should be shim on top and below. If so, your field might bind and cause major wear.

Downfall from shims that comes with kit is sometime not enough if you're not reusing your oe ones and especially if your knuckle has no shim to start with.

[slimlaudin [OP]]

How do u figure how many u need?

[NorCalPR]

Either using an sst or making the one on pirate. That will set the knuckle center in relation to the axle.

Shims do two purposes. One is setting bearing preload. The other is centering the knuckle.

[Dcal714]

I recently completely restored the front end of my 1981 toyota 4x4. When replacing the knuckles i had to order a shim kit. The shim kit came with a pull scale. The toyota manual specified that there must be 6lbs of pull resistance. The kit i ordered came with 4 different shim thicknesses. only with a coulple micron difference each. The objective was to test different combinations of shims on top and bottom unitl the specified resistance was achieved, of 6lbs on the pull scale. Since the knuckles are not machined to such narrow tollerances, the shims are used to acheive the necessary levels. Wihtout the shims, tightening the nuts of the steering arm and therein the bearing onto the bolts of the knuckles will push the grease out of the bearing.

Skipping this step in re-assembly will cause premature faluire. Not only of the specialized bearings of the knuckle due to the inability of the proper amount of grease being able to penetrate between the rubbing metal, but also potentially your power steering unit, as it will over-work itself trying to articulate motion without sufficient lubrication. Furthermore, if the wear on the steel reaches a point where some material begins to separate, it will act as sand papper would and completely destroy the bearing and the knucke.

Pain in the a**, I know. When it is all said and done, i'm glad somebody told me the right way to do it. I hope I can pass on that courtesy.

[OOPS]

The bottom shims are for centering the knuckle, with out it centered the axle seals will start leaking. Not as bad if you use Marlins Eco-Seals.

The top shims are for setting the pre-load on the knuckles. This measurement is done without the wiper seals installed on the back of the knuckle. The FSM calls for 6.6-13.2 start pull pounds. With the wider tires we run I go towards the upper number.

With out the SST I use one thick and one thin shim on the bottom to center and set the pre-load with the shims on the steering arm.

I have rebuilt about thirty axles since 99, and yet to have a failure except when I used some cheap bearings from China that TG was selling at the time, the bearing broke and also wiped out a Longfield. This happened on the street, not the trail.

I use a high tack red grease ( I use Lucas)for both packing the Birfields and all the bearings. Make sure when you install the trunion bearing races they are seated all the way down into the knuckle ball. They can be a bummer to get started, so I put them into the freezer the night before.

If you want to read the proper way to set these axles up, here is a link to the axle section of the 85 FSM.

http://www.lukemiller.org/toys/1985_toyota_4wd_front_axle_FSM.pdf

[slimlaudin [OP]]

Ok so started the te as r down..and the bottom caps have 1 big and 1 small on both sides..nothing on top..but before tear down they turned really easy..might i have other issues? And im gonna go eith the 1 big 1 small on all caps cus that purty much all i can do