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Rear spring shackle replacement

stump

stump

Member
Since you guys did such a great job with the sending unit, I though I'd build on that success by bringing you in on this project also...

Turns out the scraping sound I would hear when hitting a dip in the road was the left rear tire hitting the fender. The car has new "improved handling" type leaf springs so I'm fairly sure weak springs are not the problem.

What I intend is to replace the shackles with the 9/16" type that are 1 inch longer.

Any hints before I start?
 
Sounds like there are other issues....rear end off center.....tire size....something.

I have done 1" longer shackles by using the standard after market long shackles and cutting them down. The set I had positioned the lowest setting at 1 1/4" longer. It worked good, was easy and available, and did not have top worry about the steel I needed. Came with bolts and all.

I needed the length due to both rear tires scrubbing a bit based on being to large. It did the job.
 
Looking at pictures it would seem your tires are on the too wide side. Hard to tell if even rolling the lips would help as tire looks to sit out fairly far. What size are you running?
 
Consider that my involvement in this car's restoration was limited to writing checks... I have no idea what "fender rolling" is or how it's accomplished...

Here's what I've got...

Springs: From NPD, OE Rate 110, part #5560-23, "Special, GT Competition / Special Handling"
Tires: P225/70R14 (R), P215/70R14 (F)

When comparing the fender clearance the left side, the side that scrapes, looks to be around 1" lower; looks low from the rear also.

I ordered a pair of shackles (1" longer), also from NPD #5630-6L. I intend to replace the left (low) side first and see it that gains the clearance needed, and hopefully levels the car. The right side only if it seems necessary...
 
Rolling the fenders is when you bend the inner lip of the wheel opening up to increase clearance. Stock the lip is parallel to the top of the tire. By bending it up it moves away from the tire resulting in a bit more width clearance.

You may be dealing with an issue created by quarter panel replacement too. 225 tires should fit inside the stock quarter lip. I've seen quarters with bad shape that causes them to sometimes flare out more/less than others. You should do some measuring to make sure the rear is centered and also that the quarters are equal in their dimensions.
 
The rear end is centered as far as I can tell.

The left side is 9/16" lower than the right. I'm going to replace the left shackle with the +1" one I should receive today...

Any cautions, words of wisdom, hints, etc before I start?
 
Did you measure off multiple points to verify the full side is sitting low and not just the quarter opening? Frame rail to ground, spring mounts, etc.? Be good to know where that height difference is coming from before just jacking up the one side to "correct" it. It's possible you have one spring settling more than the other and measurements would verify it.
 
"Horseplay" said:
Did you measure off multiple points to verify the full side is sitting low and not just the quarter opening? Frame rail to ground, spring mounts, etc.? Be good to know where that height difference is coming from before just jacking up the one side to "correct" it. It's possible you have one spring settling more than the other and measurements would verify it.
Click to expand...

Took some measurements and the height difference was pretty consistent; appx 9/16". I replaced the left shackle and it increased the clearance about 1/2". Took it for a spin and filled the tank (partly to check my gauge accuracy) to add more weight. Though it did better, I still had some rubbing on the bigger dips...

I'm not necessarily in love with the rear tire size, though I do like the look. So, I could go with a smaller tire which would probably mean the same size as the front; however, I'd prefer to keep my tires if possible... Would different springs solve this or will it have to be a smaller tire?
 
Nothing in suspension will fix the difference from side to side if all measures as you say. Have you checked the front springs. If the front of the car sits crooked, the rear will also...... You may find one side sits high in the rear, not low.......

What are the wheels you are running. I am not sure of the required backspacing but that may be an issue.
 
I sit crooked sometimes and all the wife has to do is slap my other side a couple times. Straightens me right up. Wouldn't be nice if that's all we had to do with our cars?
 
"stump" said:
Can fenders be rolled after they're painted?
Click to expand...

Yes

With heat it can be done without paint damage / cracking if very patient.

without heat, probably you'll get some cracking.
 
In the tech section of mustangmonthly you wiill find some answers regarding wheels and rims.IIRC.
 
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