Power steering, Disc brakes and springs

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Feb 15, 2006
Redding, CA
Well…. going to order the parts I need to convert to disc brakes and power steering within the next few days. Getting my parts from classiccruisers.com they seem like really good people and have been helpful with a few questions I’ve had. Their ‘kits’ are comprised of inspected used and new parts and supposedly contain all that is needed to perform the conversion. In addition to the conversions I plan on installing a HFS 2 ½” lift kit, bushings, shackles etc. Somewhere I saw that shims might be needed when using a lift kit to maintain steering geometry. I need some help here because I don’t know where the shims are required or if they are in fact required at all. Any other things I should be considering prior to diving in? I’ve never attempted anything like this before so any pointers will be appreciated. I doing myself for $$$ savings and I just want to. Oh yeah, this is being done to my mostly stock 1971 FJ40.

Shims are used between the spring pack and the spring perches on the front axel. Typically when you do a spring under lift the axel starts to be tipped forward. (Think pinion is starting to point upward a bit) This can cause the caster of the steering to be reduced and lead to the infamous “death wobble”. Basically where you truck wonders around on the road as you fight it to go straight. (Been there back in the day!)

The shims come in degrees like 2.5* etc. I have used the 2.5* ones in the past. If you use them try to get the steel ones and not the cheep aluminum made ones. (Benz Springs in Portland OR. Stocks the steel ones, cheep too.) The shim goes onto the truck with the fat side forward thus tiping the axel housing back down. This gives you some caster back so the truck tracks right on the road.

Now with 2.5” lift springs running stock shackles? You will probably be fine w/o adding the shims. I ran that set up for years in HS and collage with out the shims. Of course I never knew any better back then too! I would set up the new springs as is drive it and if it seems to wonder then pick up a set of shims. You can easily add them in with out tarring down the whole suspension.

When you do your work, I suggest you do the two tasks separately. Install your new springs first then drive it to confirm all is good and no issues. Then tackle the brake swap. This way if there is any issues with one of the installs you can trouble shoot a bit faster.

Good have fun! You are going to love the disk brakes!


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