Nuttymopar

Just installed a SkyJacker 4" lift kit this past weekend. Now as i start to take off, I feel a vibration in the driveline. Right about 1100 - 1700 or so I will feel it. I am thinking it is the Center Bearing section that probably needs to have longer spacers between that and the frame. I have a Club Cab and I did install lug nuts (my spacers) as the Tech Bulletin recommends due to drive vibrations. Now I am assuming that I might need longer ones? Wouldn't that make it (1" or so spacer for ctr bearing) weak allowing it to sway or move under power?

Could it be improper pinion angle? It looks pretty straight but I do not have the proper tools to verify. Only used a Bent Coat Hanger to verify angle to yoke matched, pretty straight on from what I could judge.

Nuttymopar

Well, maybe have found my vibration problem. I looked at the Center Carrier Bearing and it doesn't look the best though I think it still works. I have purchased a new one but need to find a machine shop to pull and press on the bearing. A friend also stopped in and mentioned that my Pinion Angle looks to much. We undid the rear ubolts and rotated the 2" block around and left the shim in the way it came from Skyjacker. This did seem to help so I might try and turn the shim around next to see if better or worse. The block actually came with a degree angle also so it seemed strange to have both (shim & Block) to have the larger end in the back really causing the pumpkin to rotate pretty far. Guess it is trial and error now to find out what is the best.

AbertaRAM

The big blocks have to have the bigger end (taper) to the back of the truck. Then the two smaller shims are to go in the front, between the new springs and the trucks front axle. This is to correct the pinon angles on the axles. This should have been in the Tech. Sheet that came with the Lift Kit. I'm sure someone will correct me if I'm wrong. Hope this takes care of the problem.

AbertaRAM

Forgot the small shims the big end of the taper goes to the front of the truck.

Nuttymopar

The way they came were that the rear springs had one shim on each spring already mounted to the spring with the larger end on towards the back of the truck and smaller end on the front. Then the actual block was also tapered and I first placed them so the larger end were placed towards the back of the truck and the smaller end towards the front. Initial take off going nice and easy had a lot of vibration. I have since just switched the big block with the larger end towards the front not and still left the shim bolted to the spring which has the bigger end towards the back. That did rotate the shaft forward a little so the pinion is almost parallel to the ground, though it isn't just yet. Before it was pointing up pretty good.
It only takes about 10 minutes each side so I don't mind playing back and forth and then taking it for a ride.

AbertaRAM

O.K. this lift kit has new springs front and back. The kits I have installed have been new springs front and blocks for the back. On the kits with only blocks for lift they where all ways installed with the big end to the back. Only other thing I can suggest is the springs need to be turn around so the big end of the shim is facing forward. This may give you a level platform to start, then the blocks will give you the angle needed for the pinion. But before going through all the work to change the springs around phone up SKYJACKER and ask them. Sorry I could not help more.

Nuttymopar

You are correct. I am sorry I didn't mention that this lift has both front and rear springs but also has blocks (2" ) to replace the original blocks from the factory. I will give them a call. Thanks.

apache

the biggest issue is a difference between front and rear yoke to shaft angle. true the greater the angle the shorter the U joint life. Typically more than a 1.5 degrees difference well cause a buzz at speeds. You can buy a low budget angle finder at a hardware store. This would be your best bet to get it set right. Also look on woods drives lines for tech info in the matter.

CrewCabCummins

WHERE"S THE PICTURE'S!!!!?? WE NEED PICTURE's of that BAD BOY!!

DesertRat93

I've got 6" rear leaves on mine. It used to shake bad at around 50mph under acceleration. I turned the rear shim around, big end forward, so the pinion was more level. It smoothed it right out. My truck doesn't have a carrier bearing though, so this may or may not work for you.

It now only shakes at 85mph when decelerating , Oh well...

Nuttymopar

Can't take any pictures yet. Body was falling apart so I have started cleaning that up but it is a slow process with it being a daily driver. Pull in at night, work for a couple of hours and it must be ready to drive the next morning. Lift took all weekend to get it in but not bad for a 3 day project, among many other little things to finish it right.

Nuttymopar

Here are a couple. You can see why I am working on the body now. Previous owner didn't this right at all. They nylon tie wrapped a piece of plywood around the fender and then threw bondo on it. I think they must've been about 5 feet away when they started throwing it on.

Nuttymopar

So we cut out the old.

Nuttymopar

And started to replace with new.

plumbz

I just installed a 4.5 sky jacker lift as well and am experiancing the same rear vibrations. I am also having at about 60-70 mph front drive line noises and vibrations. I have not checked to see about block directions. Could this be what is causing the front problems as well ? Kit came with new front springs and a adda leave with blocks in the rear.