Driveshaft phasing

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Nov 25, 2015 | 05:38 PM

SuperDutyScaler

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From: South Jersey

Driveshaft phasing

Ive had a shake at 60-75mph for a few years now. New tires, rear driveshaft rebuilt etc etc, the other day a fellow member asked about the same issue and someone posted a link on how to check driveline slooe and phase. Checked mine agter work and im 11 degrees OUT!! Now my truck was on a slight nose down driveway so that could have something to do with it so tomoorw ill find a better driveway to check. But it seems i have to add a defree shim to the rear spring pack and im hoping this fixs my shake at highway speed. Now im have more in depth questions. IF i put a four inch lift on this winter and will be biying a bigger one piece block do they affer blocks in lets say five or six degrees? My rear suspension on my f350 is altered from stock so im assuming this is why the rear abgle is so off?

Nov 25, 2015 | 07:52 PM

projectnitemare

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There's a little more involved than what you think. High speed vibration you're in the right area. Low speed it's at the wheel. Phase is that all the joints are in line. Unless you had the shaft altered or pulled the slip yoke apart the phase is fine. Is it damaged? If it's been vibrating a long time it's going to need rebalanced. You need a good digital angle finder to play with driveline angles. A level surface is ideal but it can be done anywhere. You are worried about angles relative to the transmission and axle, that's independent of the surface the truck is sitting on. 1 or 2 piece driveshaft? The angles are different for each. Best place to get good driveshaft info is the Spicer website. They have the steps to setting up a driveline.

Nov 25, 2015 | 10:46 PM

SuperDutyScaler

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From: South Jersey

following these steps from a link from another thread on this site, my rear shaft is out 11*. which is CRAZY out of whack and i cant see how me adding a custom add a leaf could cause this?

DRIVE LINE PHASING

Nov 26, 2015 | 07:01 AM

projectnitemare

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Yes a different set of leaf springs will change pinion angle. A different height will raise or lower the axle. You had mentioned changing blocks. I don't know of anyone that makes the to a custom angle and I would recommend using more than one or two shims to adjust pinion angle. You may have to cut the mounts off the axle and reels the at the correct angle.

Nov 26, 2015 | 07:05 AM

projectnitemare

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I think you might be looking at something wrong as well. Out 11 degrees in reference to what? If I remember right max angle on a 1350 u - joint is 15 degrees. You should be having a lot of shudder or vibration will before 60 mph if that's the case

Nov 26, 2015 | 12:31 PM

Just Strokin

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From: Tallassee, ALabama

Notice the position of the U-joints in the yokes. the "C" of the yokes are all in the same position.

Nov 27, 2015 | 09:09 PM

SuperDutyScaler

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From: South Jersey

Shaft C's are all in line, one piece sahft off a f350 4x4 with a double carbon joint at the tcase. If you read the link it stats degrees must add up to 180. Im 11 off and all i did was add a 1" rear add a leaf, so i cant aee how a little 1" leaf spring could cause 11* of pinion angle but with my luck