New DC rear shaft, now need adjustable UCAs and help with install

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Rev1911

Rev1911

10 Year
Joined
Sep 29, 2012
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8
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I will gladly provide pizza and beer if one of you fellas could help me (and show me how to) install the Slee UCAs I've got en route. Any takers?

My pinion angle needs adjusting after the DC shaft went in. I've got vibes. I also have a stock shaft if anyone wants it.. Provided I can get this DC one running smoothly.
 
i would be willing to help drink your beer but man i still have a ton left on mine. what part of town are you?
 
I'm in the same boat man, I'd help but my garage is occupied until at least February.

With a DC rear driveshaft, there should be no skill involved, just point the pinion about two or three degrees down from aimed straight at the transfer case and you're golden. The vibes you're getting are because the lower joint has nothing to cancel it out.

When you have two joints, they have to be at the same angle so that when one moves one way, the other moves opposite, and the motion is cancelled. Double cardans have two joints to cancel each other out, but the lower is left to deal with itself. straighten it to within a couple degrees of straight (to deal with the pinion coming up under acceleration) and it won't have to compensate.
 
cool breeze said:
i would be willing to help drink your beer but man i still have a ton left on mine. what part of town are you?
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Northeast. Powers and Dublin area.

black95 said:
I'm in the same boat man, I'd help but my garage is occupied until at least February.

With a DC rear driveshaft, there should be no skill involved, just point the pinion about two or three degrees down from aimed straight at the transfer case and you're golden. The vibes you're getting are because the lower joint has nothing to cancel it out.

When you have two joints, they have to be at the same angle so that when one moves one way, the other moves opposite, and the motion is cancelled. Double cardans have two joints to cancel each other out, but the lower is left to deal with itself. straighten it to within a couple degrees of straight (to deal with the pinion coming up under acceleration) and it won't have to compensate.
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I appreciate the info, Luke.

I read up on what the angle should be and how to theoretically get it there, but my question lies in the process. Jack up the truck, jackstands under the frame for support, dismount wheels, remove OE UCAs, read Slee instructions and determine correct length c-to-c for new UCAs, rotate axel to correct angle (this is the part I'm not sure how to accomplish.. just grab and twist?), install new UCAs, tighten/torque to spec, wheels back on, lower back to earth, test drive?

The arms should arrive tomorrow so I'll get a chance to look at the instructions.
 
I would be happy to take that old shaft off your hands if no one else has yet. Thanks! I wouldnt know what to do anymore than you but I live just a few minutes away. If you need a hand just text me @719 37, 11983
Ryan
 
mountainmanryan said:
I would be happy to take that old shaft off your hands if no one else has yet. Thanks! I wouldnt know what to do anymore than you but I live just a few minutes away. If you need a hand just text me @719 37, 11983
Ryan
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If I can get the new one dialed in, it's all yours. I'd certainly appreciate the help. I'm confident we could figure it out, I'd just like to get it right the first time and not end up with any accidental spare parts. :)

Picked up a floor jack today and will get jack stands tomorrow. Should be set by the time the arms get here. Won't have time to bolt 'em on til thurs or later, though.
 
karas said:
I live close by as we'll but don't have a lot of time to help, but you can borrow my jack stands if you would rather not buy them. I have a big set and a littler set
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Much obliged. Found these on CL http://cosprings.craigslist.org/tls/3430196150.html and was going to call in the morning. I'm at 6" of lift on 37s so I need substantially tall stands to meet the frame.
 
Man, be careful. How much does your 80 weight? Built wagons get pretty heavy. I'd think about 6 or even 12 ton jack stands.

I might seem overly cautious, but I always hate getting under a car.

Good Luck.
 
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Fitzgerald said:
Man, be careful. How much does your 80 weight? Built wagons get pretty heavy. I'd think about 6 or even 12 ton jack stands.

I might seem overly cautious, but I always hate getting under a car.

Good Luck.
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Yeah, I was eyeing 6ton stands at advanced auto. The truck is fully armored underneath so it's not light.

Got the arms in today. No install instructions included but I get the general idea. Still need to figure out how to rotate the axel forward (toward the tcase) to correct the angle. Is there a trick or can i just grab it and twist? Then I guess just measure the mounting holes and adjust the arms to fit.
 
I was eyeing the 3 ton rating on those stands too. 80's are in the 6000 pound area, so holding up one axle would be ok.

Anyway, measure to the center of your hubs. Jack up the truck and pull the tires. Put jackstands under axle tubes and get it sitting as close to ride height as you can using hub center measurement. Pull your upper control arms. Put jack under the nose of the pinion on flange and jack it up. The axle tube will rotate on jack stands. You can eyeball the driveshaft angle.

One question, does the rear of an 80 have a track bar? Seems like if you rotate the axle that far you'd have to move track bar and shock mounts.
 
I've got an adjustable rear panhard.

Tried to get some shots of the pinion angle and the lower coil spring seat. You can kind of see how rolling the axle toward the rear to correct the angle will put the coil spring seat at a substantial angle in relation to the top mount.

image-990738729.webp


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image-1465899386.webp


image-1752595313.webp
 
That driveline angle looks pretty good to me. With a DC driveshaft, I wouldn't think you would be getting vibrations from that. Have you checked the front? Pulled it out and drove without it? I know you were not having trouble before new shaft, never know though. Is the rear driveshaft in phase? Who built it?
 
black95 said:
That driveline angle looks pretty good to me. With a DC driveshaft, I wouldn't think you would be getting vibrations from that. Have you checked the front? Pulled it out and drove without it? I know you were not having trouble before new shaft, never know though. Is the rear driveshaft in phase? Who built it?
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Haven't checked the front, yet. It's a DC, too. Looking at the parallel lines on the diff and then following towards the tcase, the rear ds doesn't seem out of like to you? I guess the camera angle might be playing with the lines, but to my (untrained) eye, it seems like the pinion angle could rotate back a bit in order to be get the ds coming in straight.

The shaft is from Slee. Balanced and prepped before shipping, according to them. Had no vibes but a nasty "grrrrrr" on decel with the OE rear shaft. Had this one put in and now vibes show up.
 
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Those 12 ton stands are priceless for a 4x4 guy. 30" standing height! I put off buying them, and I kick myself thinking how long I denied myself the purchase and got by with dangerously short jack stands combined with wood blocks. Stupid.
 
Got my stands. I'm ready to knock this out and get the rig back to smooth... Or as smooth as it can be, anyway.
 
im done with my 12 tons plus i have a pair of 6 tons...you can borrow either if you need.
 
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