guitarman376

I am getting ready to replace my leaf springs, and while going through the repairs in my thoughts I realized I am unsure how to get the rear end aligned properly after removing and replacing the u-bolts, and spring plates. Is it as simple as measuring with a bob on both sides of the axles with the quarter panels?

I'm assuming the first step of reinstallation is to install the new leafs, then the ubolts/plates loosely , then shocks, then measure, adjust, then tighten?

Jonk67

There are locating tabs/nubs and holes on the axle perches, leafs and bottom plate/shock mount so they go together one way and there's really no ajustment or need to measure. If the rear isn't centered the car may be bent from a previous accident. Otherwise it should be within ~1/4" from side to side.
Jon

67mustang302

Yup. The perches on the axle have holes that go over a locating dowel on the leaves(which is actually part of the little bolt that helps hold them together).

So basically, if you have misalignment in the rear of a leaf spring car, something is bent/damaged/incorrect somewhere.

guitarman376

Haha now I feel dumb. Question answered.

andrewmp6

The spring perches are there to keep the rear end from walking left or right.And good luck with the front bolts on the leaf springs mine where rusted in place i had to cut them off.

jaw1962

Yes.. Good luck. I had to cut all four of my bolts. But the holes on the perch and the nubs on the leafs sure made it easy to get back together.

guitarman376

One more question: Anyone know which U-bolts to go with? Way too many options....
1) http://www.mustangsplus.com/xcart/19...6-X-3-X-8.html
2) http://www.mustangsplus.com/xcart/19...-3-4-Long.html
3) http://www.mustangsplus.com/xcart/19...ng-U-Bolt.html
4) http://www.mustangsplus.com/xcart/19...7.75-Long.html

I don't know which ones are stock length (I'm assuming I don't need longer ones)

scottybaccus

You actually can have an alignment issue, even though the leaf setup has a locating pin. Parts wear, mfg tollerances, etc.

To check it, drop a plum bob off the end of the axle with the wheels off and the car on stands. Put the string in a place that will give you exactly the same position on both sides. I use the front side of the axle tube, just outside the spring perch, touching the spring pack. Drop two more points off the seam at the front of the rocker panels where they meet the cowl section under the front of the doors. Find the centerline between the front two pints and measure diagonally to each point at the end of the axle for square (thrust angle), longtituinally for wheel base. The tolerance should be no greater than about 3/16" (I like 1/8th). Last, use a straightedge, held vertical on the axle flange to measure to the outer surface of the fram box in the rear wheel house. These should be within 1/4" (I like 1/8th) for centering the axle.

To adjust, loosen the ubolts and nudge things around, then snug them back up. Measure again, then torque everything down. With new springs and bushings, you might wanna drive it a couple hundred miles to settle everything before you go through this process.

andrewmp6

Link 1 or 3 will do 2 and 4 are longer for people that use a lowering block between the axle and spring.