I tried every single way to get this thing to fit correctly short of trying to drill another hole..heres when I tried middle then back to front and got no success..but this will give u an idea of how much its off ..if I just bolt the front and then back its fits fine..but the middle wont align.....btw its a mid eye spring...

the center bolt on the leaf spring will not line up to the hole on the axle perch... if I put the front eyelet bolt in first it wont line up to the perch hole..ive tried shackle first then axle but it comes up short at the eyelet bolt...I can mount eyelet and shackle but axle hole is off..this sux

Bentworker wrote:

I don’t quite get what you are describing.

Are you saying that the sleeve in the front bushing is too wide to fit in the hanger?

Normally I’d wrestle the front of the spring into the hanger first with nothing else attached, using the spring as a bit of a bar, install the front eyelet bolt, then lift the spring under the axle until I can assemble the rear shackle. After that u-bolts and torque everything.

Problem is your spring not your housing.  It is either made wrong or it belongs to a different car.  Get a new one.  Any Mustang parts house has them.

I have a feeling that the previous owner replaced just one spring at some point. Those things need to be bought in pairs. I would buy a new set.

Looking at the wear marks on the two springs, it looks like one of the springs needs to be rotated 180 degrees.  The two wear patterns don't look like they are facing the same direction.

this is the original way I tried to install..it was actually the closest I got..i dint thing I loosened the rear sway bar enough to be able to move the axle ...im going to try this again

Muzz 66 wrote:

While the East Coast and Mid-country guys are asleep we California dudes are still up workin'!!!
Assuming the new springs are the correct length and both are even, attach the front part first then the rear at the shackle. Leave the rear end up and off and then put on the other new spring, front then rear.  Then lower the rear housing down onto the leaf springs. Even if the mounting point for the axle housings are slightly off from the old springs, the yoke should suck up or let out a little with no problems.  Again, assuming all is even. 

the newer one is short to the axle hole..so its like 1/2" towards the front of the car

TKOPerformance wrote:

Yeah, the spring center bolts MUST be in the same position on both springs or the rear won't be in the car straight and the car will pull.  Is the one with the shorter measurement from the front to the bolt on the left side of the car?

you have that all correct..the middle pin would be the problem...im going to loosen the rear sway bar more...I think I was so frustrated of how long it was taking me I started to neglect loosing it more.....after reading your advice I considered this and hopefully is my problem and hopefully I can move the axle forward..its only off by about 1/2" of fitting in the hoe.

Bentworker wrote:

Going off what you posted in your Shelby drop thread you are installing two brand new mid eye rear leaf springs.

I am still having a hard time picturing what the problem is unless the center pin of your new leafs is way off specification.

When your are replacing the rear leaf springs there is nothing restricting the movement of your rear axle... except for the driveshaft slip yoke bottoming out.

Do not do one side at a time... remove both springs then install both springs.

Car supported by subframe on jackstands...
Both rear leafs removed.
Axle supported on jackstands up out of the way so you can swap springs...
Install new springs. Front eyelet bolt first, then shackle. After that just use a jack to lower the rear axle onto the new springs. You should be able to move the axle easily until it drops onto the locating pin. Slap on some u-bolts, torque everything and go for a ride.

haha..like I told rufus68 it is just marked up from me trying to make it fit..the other is the one I pulled out

6sally6 wrote:

Rufus68 wrote:

Looking at the wear marks on the two springs, it looks like one of the springs needs to be rotated 180 degrees.  The two wear patterns don't look like they are facing the same direction.

^^^^^^^ X-2. Rotate the one on the left 180* and see if the bolts line up!
6s6
 

All springs '65-'73 are the same dimensions.  The spring rates are different, and you will see different part numbers year to year, engine to engine, etc., but that doesn't explain your problem with the center bolt location.  I think either you have one wonky spring, either manufactured incorrectly or from another vehicle. 

Bolted to Floor wrote:

I like the tag line in your posts, the can do attitude is great. I always went under the assumption on repairs that it’s already broke, how could I make any worse! ...... did mange to on occasion though 

If the old stuff fit and the new stuff doesn’t, it’s time to start measuring. Start with the old and do all....
Eye to eye on both springs
Front eye to bolt for spring pack
Back eye to bolt for spring pack
Nut size on spring pack
Holes in axle perches
Diagonally from front spring location to back frame bolt hole for shackles to know it’s square

You will know that the parts are all the same and the spring mounts are square.

The rear shackles are loose at the frame to allow them to rotate?

You made mention of a rear sway bar? The end links that go from the bar to the frame should be extremely loose at all four mounting points or removed altogether to allow for moving the rear end around. Leaving the driveshaft installed is ok.

The nut for the spring pack may be smaller than the hole in the spring perch and allow for a small amount of wiggle room. It’s not a bad thing, just make sure to push the rear end the same direction on both sides. Otherwise, the rear end could be out of square with the car and cause the tracking to be off. It’s not a lot, but it will show up in the steering wheel when you drive. Meaning the steering may have been centered before and is now off center while driving straight down the road.

BINGO!
 

Ditto on the measurements "Bolted to Floor" suggests. 
You mentioned the center bolt on the spring is off 1/2", I assume this means from the front eye, this needs to be corrected or the rear end will be crooked and you have problems with cornering, braking, etc.  It may not be noticeable until you get into an emergency situation and then things can get serious quickly (like spinning out of control).