Topic: i have a bad viberation after sky disc brake and different 3rd

[NaturalDisaster]

ok i just put a different third member in the rear with 5.29's a spool and a sky-man rear disc brake conversion and now my truck has a really bad viberation at about 15 to 20 mph and i have not ran it any faster than that the only thing i have done outta the ordinary to it is it has a square drive shaft in the rear and i layed down some beads of weld on one side of the shaft and then flipped it over 180 and welded some more beads on that side and and left two sides bare from weld is that maybe a possability because the 5.29's will spin the drive shaft alot faster. because before the truck was good for about 55 mph with a square shaft without any viberation at all or is their any other ideas to look for Thanks all Ryan

[phlatbed]

are the gears set up right? good pattern and everything?

[Yota Up]

It's your seal on the input shaft for your diff.  Open it up, pound out the pinion, run to the store and drop $10 and git er done.

Had a bad vibration myself, and this fixed it.  And that's after eliminating everything else, in my case.

PS:  I don't see how disc brakes vs drums would affect anything like that, unless those discs are badly warped or just have a load of metal slapped to one side - haha.

[welder2000]

How would a pinion seal cause a vibration? I'm asking because I'm chasing a vibration my self.

[NaturalDisaster [OP]]

ya im a little confused on the pinion seal too. i drove the truck that had the 3rd member came out of and it was smooth and good but i honestley didnt really look at it before i droped it into my truck and ya your right i dont see how the discs could even cause any sort of viberation at all

[KDXSR5]

Warped discs can cause a bad vibration in certain vehicles. Some one pulled a subaru legacy wagon in the other day with a really bad wobble, and it turned out to be warped rotors. We turned them, re-installed them, and no more death wobble. So don't rule out disks until you check run out and stuff.

[OOPS]

Is your d-shaft phased right?

[TRACKER]

Is your d-shaft phased right?

x2

drive shaft bolts tight?

[Not A Toy]

I would think welding the beads could be a cause for some nasty wobble..and I would think that wobble associated with your new brakes would only really show up when you were actually braking..