Drive shaft length issue

[SFEbody]

My drive shaft problem:
Ok, some may know I am doing my restoration of the drive train from a S/6-3speed. to a 440-4 speed. Just about finished and took my original driveshaft to a great company here in LA and had them cut it down to 45.60 as per everything I read. Now I get it home and install it or try and I put the slip joint end into the tail shaft all the way to the u joint of the yoke. Yet, the rear u joint is still about a 1" + to long. My real question so I can have the shaft cut again is - How far forward from my 8-3/4 rear diff yoke? I remember back in the day, it would be 2 inches at least from the rear when all the way in tail shaft...... please weigh in if you can make sense of my post. Much appreciated.

B.

 

[aussiemark]

The oem manual has 45.60 for the 383 w/8-3/4 axle (should be same as 440) and 44.60 for the 440,426 W/9-3/4 all measured from centreline of yoke bearing bores. The Dana is larger needing an inch shorter shaft so I can't figure out what's going wrong here. Have you measured the shortened shaft to check they have done what you asked and not taken the measurement from other locations or something. Is there a wear mark on the slip yolk where the seal rubs this would be a good indication where the slip yolk spends most of it's time if so just slide it into the transmission until the wear mark lines up with the seal (with the rear suspension under normal load) and see how much extra length you have at the diff end. At least they didn't cut it too short then you would need a whole new one.

 

[SFEbody]

Thanks Aussie, those are the measurements I worked from but will have it re-cut to 44.60 so that it fits. Really weird the only non original is the leaf springs and I am thinking possibly the perch holes may be more forward than original.

 

[Locomotion]

FYI
When actually fitting/checking the driveshaft in the car, I believe that when the suspension is unloaded and the rear axle is hanging, the driveshaft gets pushed into the trans. (Distance gets shorter between the rear & trans.) So that will help provide the maximum length minus clearance.

 

[SFEbody]

Anyone able to give me their dimension from the tranny tail shaft seal to the front part of the rear diff yoke?

 

[Daves69]

IMO, Shoot for 1" clearance from yoke bottoming in the trans and don't worry about where the seal boot end is.

Really weird the only non original is the leaf springs and I am thinking possibly the perch holes may be more forward than original.

Are those MP springs? Are your rear spring shackles angling down toward the rear with weight on them?

 

[SFEbody]

Yes the shackles are angling down toward the rear diff....I take it that is a bad thing? and the cure is?

 

[Locomotion]

Make sure you have the proper leaf springs for your E-body.

 

[Daves69]

Yes the shackles are angling down toward the rear diff....I take it that is a bad thing? and the cure is?

No, that is what you want. You'll need to measure the spring front segment to determine what you're working with though.
Note the chart Locomotion posted. 22" front spring segment. The MP springs require a longer front spring hanger as the front spring segment is shorter.

 

[SFEbody]

Thanks Dave, I will measure tonight when i get off work. Much appreciated your help. Is that 22" from the bushing to the spring pin hole?

 

[Daves69]

Yes, center to center.

 

[Locomotion]

No, that is what you want. You'll need to measure the spring front segment to determine what you're working with though.
Note the chart Locomotion posted. 22" front spring segment. The MP springs require a longer front spring hanger as the front spring segment is shorter.

Are we understanding that the same way?
The shackle needs to hang down with the rear spring eye angled away from the rear. As the springs load up, the shackle pivots towards the rear end housing.

Angled "back" like in the pic.

 

[SFEbody]

Thanks to everyone for their input, I FINALLY resolved it and yes it was the cheap aftermarket springs The pin for the perch were nearly 2" forward. I swapped back to original springs and BAHMMMM the stars are all aligned,,,,,, test drive soon!

 

[Daves69]

Are we understanding that the same way?........

.......toward the rear diff....

Lol, Sorry folks, I read the post wrong and left out the "diff".

 

[Daves69]

FWIW, Long hangers ....
www.manciniracing.com/mopfronhanbr2.html

 

[SFEbody]

Ok folks, new problem. I got my driveshaft issue resolved but now the rear of my car sits 1" lower on the driver side than the passenger side. Is leveling the rear of the car as simple as placing shims/wedges between the perch and leaf springs? or is there a better way? Any help is appreciated

 

[aussiemark]

Your information is very helpful to me because shipping heavy items to Australia is expensive so when I order parts I need to know they are going to work returning these parts is not an option so they were Mopar Performance springs?

 

[SFEbody]

Used the original springs from my /6, 7 1/4 rear end. Rode perfect before swaping rear ends.

 

[Daves69]

I'm not familiar with /6 spring sets and leaf count.
You haven't changed any thing in the front as in adjusting torsion bars?
Might you have them on the wrong sides?
U-bolts torqued properly?

 

[SFEbody]

Dave to your questions:

You haven't changed any thing in the front as in adjusting torsion bars? Converted to RT front end to accommodate a 440 from a slant 6

Might you have them on the wrong sides? Checked left is on left and right on right.

U-bolts torqued properly? Torqued to specks in service manual (45)