rear drive shaft. vibrates like crazy

[84CUCV]

i got a 86 m1009 with no 208 or drive shaft. put it together with what i had.. new u joints in the drive shaft. no heavy rust or dents. i never drove it before. i got it missing the parts.. checked everything i could think of. axle seems fine.. suspension is all stock.

any ideas? need it done so i can sell it. thanks

 

[84CUCV]

anyone

 

[diesel4me]

If it is possible for the splined yoke to be installed in any position (some have a keyed spline so it only will go on one way ,the "right" way),the u-joints might not be phased properly,the yokes should be exactly 90 degrees offset from one another...also ensure the slip yoke goes in the t-case far enough..

..the U-joints might have gone together with a needle out of place or the yokes may have been pinched together during the u-joint install,see that they flop around easily with no binding with the shaft out...if it was bent enough to shake the truck it should be easy to see with it up on blocks,running in gear...it might be unbalanced too,but usually thats a minor condition that only shows up at high speeds...some guys have used worm gear hose clamps to balance them..

 

[84CUCV]

u joints seem good.. there is a spot where i think the piece of metal was to balance it.. its gone.. so thats where ill start. thanks

 

[Blue85]

So how do you know it is the driveshaft?

 

[84CUCV]

axle seems fine.. tires are balanced right.. on the drive shaft there is 3 spot weld where a piece of metal was to balance it.. some how it come off..