Drive shaft vibration?

So when i lowered(5/8) my truck it had a small vibration in the rear wheels,basically the pinion angle is off,Plus the bed shaking from start to 65 is a dead giveaway.I crawled underneath of it and took a measure ment of the driveshaft and came up with 2*.Then i unbolted the shaft and took a measurement of the yolk and came up with -3*.This is where im stuck.What is degree pinion shim would i need.I also jacked up the rear end and had wifey put it in drive running and the damn rear end wobbled so bad.Any clue?

are the u bolts tight ? is it a 1 piece or a 2 piece shaft ?

what kind of truck, is it just plain ol ujoints or is there a double cardan in there on one end?

if its plain ol ujoints on both ends, the flange on the differential should be the same angle as the one on the transmission or transfercase

ummmm no .there is always a diff thrust angle on them

are the u bolts tight ? is it a 1 piece or a 2 piece shaft ?

1 piece drive shaft.

what kind of truck, is it just plain ol ujoints or is there a double cardan in there on one end?

if its plain ol ujoints on both ends, the flange on the differential should be the same angle as the one on the transmission or transfercase

07 silverado 2wd,rear flip kit came with 1"lowered shackles too.I thought the saddles that the axle sits in have offset pegs to align DS but i guess not.The u joint are in great shape too.pic is when its parked

http://www.4xshaft.com/driveline101.html

should apply to lowered trucks too

it looks by the pic ya posted the yoke is at a upward angle id dive the nose down a bit in most cases -2 deg is what ya want

Was gonna say before it got posted to check tire balance but this happened with my old wheels/tires too so they are out.

88 so with the driveshaft bein 2* and addin a 2* shim which is at -3 i measured would make the yolk at -1 or even zero under load.

should put ya close to that

you have a magnetic angle finder?

Also being that small of a degree really can cause so much vibration.damn

you have a magnetic angle finder?


Yes thats what i used for my measurments.

it dont take much to bind up

driveshaft(phone pics in rain)
http://file048a.bebo.com/15/large/2009/04/21/01/8662774463a10653439818l.jpg

yolk
http://file048a.bebo.com/15/large/2009/04/21/01/8662774463a10653439872l.jpg

This reminds me I got to check mine…I get a little vibration around 70mph

ya wanna measure the tail of the tranny and the yoke of the diff for ref not th shaft

So i got to crawl under there tommorow and drop the ds and measure the tranny tail.Should i keep the truck level again or is it gonna mees up if i go higher in the rear or side to climb under it?

always measure at ride height and load ,never trq or measure susp components unloaded

just so im not completly dumb,i donot need to check the front while it is running do i.That may be a problem.LOL

mine in my 94 silvarado was off a tiny bit.It killed U-joints every 6 months.