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Centering Rear Axle during Spring Install


PostMaster General
NAXJA Member
OK, one more Q..... Last time I did springs it was an AAL which made it easy to recenter the axle (front back recenter) as I had the old spots on the leafs...... now with the new leafs and shims I kind of guestimated.... do I measure from the bushing or just bulls eye it??? (8.25 rear end)

The center pins should be long enough to go through the shim and into the spring perch.
And be sure its (center pin) in deep enough or the axle can shift.
Kejtar said:
Hmm...... what if they are not long enough to go through the shims? or barely? Do they make them with longer "heads" ?


Yes, they do. If the heads don't firmly engage the spring perches on the axle, don't try to drive the vehicle. Shims should come with centering bolts that have taller heads.
One thing that I didn't think about.... what if they engage into top part of the perch (The plate that comes down) and due to the shim (only 3") they barely make it into the bottom hole (if any?) BTW I believe that the bolts are the ones that came from the manufacturer for those springs (and the previous owner used shims as well as the kit originally comes with shims.. I can see imprints of them on the bottom of the spring).

Get the RE shims. They are 2 1/2 inch wide steel and they have a countersunk hole so you can bolt the shim to the spring pack with the centering pin. Axle centering is a snap! The steel won't deform like aluminum shims. I could only find 2 inch wide alumnium shims when I first lifted my Jeep and they were constantly squishing out. No problem with the 6* steel shims. I check u-bolt torque after every 'wheeling trip (as should anyone else using degree shims), the u-bolts were constantly loose with the aluminum shims, they have stayed tight so far with steel.
Yeah -- aluminum is subject to "creep" under compression. That's why they stopped using aluminum for house wiring. After a few years, the aluminum where it was clamped by the screws at switches and outlets would "relax" enough that it wasn't a good contact any longer. Increased resistance = increased heat ==>> fire.