Relocating the rear differential 1.25” towards the rear of the vehicle on a 72 Dart

-
Heywodja

Heywodja

The Heartbeat Stops Here
FABO Gold Member
Joined
Aug 16, 2014
Messages
1,657
Reaction score
1,486
Location
Texas
Right now my rear leaf springs are in their stock location on the dowel pin centered on the rear end perch.

I have always been bothered about how close the front of the rear end is to the wheel opening in my case about an inch an an eighth away from the wheel lip.

I was looking over the rear spring perches this evening and I noticed that the was a round hole in the center of the perch, and two square holes on the perch one located about 1.5 inches forward and one 1.5 inches aft.

Could a guy just loosen the clamps drill the front perch so it would accommodate the locating pin and relocate the pin the the forward position, which would relocate the rear axle aft?

Me thinks this would look much better but is there some geometry or other issues to consider?
IMG_0479.jpeg
IMG_0477.jpeg
 
Last edited:
Heywodja said:
Right now my rear leaf springs are in their stock location on the dowel pin centered on the rear end perch.

I have always been bothered about how close the front of the rear end is to the wheel opening in my case about an inch an an eighth away from the wheel lip.

I was looking over the rear spring perches this evening and I noticed that the was a round hole in the center of the perch, and two square holes on the perch one located about 1.5 inches forward and one 1.5 inches aft.

Could a guy just loosen the clamps drill the front perch so it would accommodate the locating pin and relocate the pin the the forward position, which would relocate the rear axle aft?

Me thinks this would look much better but is there some geometry or other issues to consider?
View attachment 1716342644View attachment 1716342645
Click to expand...

driveshaft length and less weight on the rear tires ,if your traction limited it`ll hurt , probly wont hurt a driver...
 
I did that on my Duster to center the wheel/tire in the rear opening. The leaf spring shock plate will need reworked to move it back with axle as well.
 
Springs won't work right on acceleration. Lengthen the front hanger studs and put spacers in. That is what I did . The tires would hit the rear of the quarter hitting dips at speed though. So I installed little splash guards to protect the paint from tire rub. I ran 29x14.5 when they wore out I installed 28x14.5 on 12 inch wide wheels Pictured below. I had clear vinyl on the bottom of the quarters . The rubber never stuck you could wipe it right off.

image1.jpg
 
Ive heard of spacing the front hangers back, but usually only 1/4-1/2".
I used the super stock spring hangers when I changed to ss springs, and drilled the hanger where I wanted. The rear moved back an inch.
I certainly never noticed any loss of traction. Best of 1.59 60 ft.
Rear is centered better, and I have room for a 30" tire.
 
I used the US car tool mini tub and inward spring relocation as well. I am running 325/50 R15’s that are 27.8 tall on a set of 15x10 steel wheels.
I am currently using ESPO springs, but looking at CalTracs mono setup pretty seriously.

When we did the spring relocation unfortunately we did not consider that we could have moved the forward mounting location rearward.

I will also see if drilling some new holes 1/2 to 3/4” or so rearward would be possible.

Will the some pics tomorrow.
 
I'm just askin this but how can it ever make contact? Even at full jounce the tire will not touch. How can it move? It won't.
 
RustyRatRod said:
I'm just askin this but how can it ever make contact? Even at full jounce the tire will not touch. How can it move? It won't.
Click to expand...
Yep … tire moves rearward as springs compress.

I did add a 1” aluminum block as a spacer to my Swinger so I could run a tire that would rub otherwise .
 
I don't think it's hitting his wheel opening, but the sight of it just bugs him like it does me...lol. It just looks all cattiewhompused with the tires not centered in the opening. I'm going to fix it on my Duster when I down it for the build and will probably do the same with the 65 Barracuda. The things that bug us! :realcrazy: :)
 
Heywodja said:
Right now my rear leaf springs are in their stock location on the dowel pin centered on the rear end perch.

I have always been bothered about how close the front of the rear end is to the wheel opening in my case about an inch an an eighth away from the wheel lip.

I was looking over the rear spring perches this evening and I noticed that the was a round hole in the center of the perch, and two square holes on the perch one located about 1.5 inches forward and one 1.5 inches aft.

Could a guy just loosen the clamps drill the front perch so it would accommodate the locating pin and relocate the pin the the forward position, which would relocate the rear axle aft?

Me thinks this would look much better but is there some geometry or other issues to consider?
View attachment 1716342644View attachment 1716342645
Click to expand...
Longer front spring mounts
 
RustyRatRod said:
I'm just askin this but how can it ever make contact? Even at full jounce the tire will not touch. How can it move? It won't.
Click to expand...

Right now it looks like there won’t be any contact with the tires I have at basically 28”. I am running 3:55 street gears.

It at some point I may like to run some taller tires and steeper gears, and it looks like that may not be an option with the current setup.

And it does bug the crap outta me that it just doesn’t look right.. lol
 
Guys, his springs are relocated to the frame so there are no front mounts to shim.

He could simply redrill the front mount holes 3/4" or so rearward. I certainly wouldn't move the housing to the front hole in the perch like he's proposing. You certainly could try, but you'd have to do the same with the bottom shock mount plate. Of course the driveshaft is then pulled out 1.5". That's kind of a lot and wouldn't sit well in my mind. It needs the support or it could beat the hell out of the rear bushing. Plus the rear shackle angle may be too much at that point and the shocks may even be hitting the housing too.
 
AJ/FormS said:
If you move the rear back, sooner or later the shocks will hit the factory tank, and/or, be impossible to pull off the lower studs.
Click to expand...
Yep. Also the rear will start getting very close to the tank , especially with a Dana 60.
 
It looks like from the pic that you have a radial. If you ever run a bias ply slick , they can grow quite a bit at speed and might make contact with the leading edge of your quarter.
 
I simply reroll the front edge of the quarter.

I also do some relocation work on the K members on
the Stock/SS A body cars.

I best not tell you why!
 
Last edited:
Heywodja said:
I used the US car tool mini tub and inward spring relocation as well. I am running 325/50 R15’s that are 27.8 tall on a set of 15x10 steel wheels.
I am currently using ESPO springs, but looking at CalTracs mono setup pretty seriously.

When we did the spring relocation unfortunately we did not consider that we could have moved the forward mounting location rearward.

I will also see if drilling some new holes 1/2 to 3/4” or so rearward would be possible.

Will the some pics tomorrow.
Click to expand...
Boy are the rear leaf springs a bear to drill!
 
mopowers said:
Guys, his springs are relocated to the frame so there are no front mounts to shim.

He could simply redrill the front mount holes 3/4" or so rearward. I certainly wouldn't move the housing to the front hole in the perch like he's proposing. You certainly could try, but you'd have to do the same with the bottom shock mount plate. Of course the driveshaft is then pulled out 1.5". That's kind of a lot and wouldn't sit well in my mind. It needs the support or it could beat the hell out of the rear bushing. Plus the rear shackle angle may be too much at that point and the shocks may even be hitting the housing too.
Click to expand...
Good to know. I thought he had stock front hangers.
 
Redrill your hangers 3/4 or1" farther back. At 3/4, you might not need to alter the driveshaft, and the shocks should still clear. (The three extra holes were factory ss hanger locations)

20211106_134735.jpg
 
Last edited:
3/4" is about the maximum amount the rear housing can be moved back before the stock shock mounts have to be modified. Shocks will hit the axle tubes.
 
Going to call Calvert Racing in the morning and check into a mono-leaf setup with caltracs.

Not too sure about how it will behave on the street.
 
You must log in or register to reply here.
-

Back
Top