Could this be it!!!!! (Vibration out of the whole)

[rsjohnsn]

Ok, I may be missing something here but lets get back to the rear spacers. If you have installed them with the thicker/taller side to the rear then you are turning your rear pinion down. By turning the pinion down when you are doing a lift is completely the opposite of what you are supposed to do. I would think that the thicker/taller part should be toward the front which in turn rotates the pinion up more in line with the driveshaft and tranny. This would be so much easier with pics.

Scott

 

[Norcal250]

Ok, I may be missing something here but lets get back to the rear spacers. If you have installed them with the thicker/taller side to the rear then you are turning your rear pinion down. By turning the pinion down when you are doing a lift is completely the opposite of what you are supposed to do. I would think that the thicker/taller part should be toward the front which in turn rotates the pinion up more in line with the driveshaft and tranny. This would be so much easier with pics.

Scott

the thicker/taller side to the rear would kick the pinion UP towards the body... the only time you should put the thicker/taller side towards the front is when you are lifting a vehicle with the leaf springs UNDER the axle... in that case it would be a degree shim not a block tho... putting a block between the axle and spring on a vehicle that is sprung-under would lower it... hope you figure it out soon boadie... I went through the same BS with my old truck...unfortunately nothing I tried worked... shims, carrier bearing spacer, tranny mount... finally I gave up and just went for the one piece driveline... I know how annoying it is!

 

[rsjohnsn]

Your right, I forgot about the axle being under the springs. Next time I will think before I speak! I have done a few lifts on these trucks and I can't believe I was thinking of something else.

Scott

 

[Boadie]

You guys are on the right track. SOA vs SUA spring under axel spring over axel. The thread I read was for spring under axel. Well I just put myself through Driveline 101. I'll post the the link but I printed it off yesterday and now it does not work today.

http://www.4crawler.com/4x4/cheapTricks/Driveline-101.shtml

This technical article is pretty explicit on U-joint angles and driveline angles.
To sum it up the pinion flange needs to be as close to O deg. on the verticle plane as the drive shaft is on the horizontal plane. Do the same to joint out of the tranny. The only question I still have is the middle joint. It does not really cover this. I found one site saying you treat all three joints the same. I am not understanding this as well becuase Driveline 101 just does not cover it specifically. Like on the rear you would put your angle finder on the pinion flange coming out of the diff. lets say it 68 deg. (68 deg.- 90 deg=22 deg. from verticle). Then put your angle finder directly on the shaft and find out how far from horizontal which in this casehe explains is 22 deg meaning the pinion angle is 1 deg lower then the angle of the drive shaft. Repeat for front and I guess repeat for middle minus the fact I dont think there is a flange to put you angle finder on ( I dont remember). So both angles on each joint needs to cancel each other out. I havt to figure out the middle joint.

 

[rsjohnsn]

I would think that once u set the pinion angle on the rear axle and the angle coming out of the tranny then the center should then be set. There is a calculation for the size shims on the carrier in regards to the lift but I can't seem to find it. I would just try to get both ends set correctly and then add enough shims on the carrier to keep it where it needs to be. I hope u get it figured out soon because u are causing my brain to work

Scott

 

[Boadie]

Thanks for your concern and the OT with your brain. It sure is nice to have good people to talk to especially when your having problems.

The only rule Ive ever herd of was 1/4" per inch of lift. This is supposed to be all you have to do though. Im pretty sure my problem lies is that this is what you would do if you did not use a tappered block.

I think you are 100% correct

In my case I used a tappered block So the 3/4 of an inch I shimmed the carrier bearing might have been to much. Just by looking at my rear pinion angle which is pointing up compared to my drave shaft angle I think Im running down hill.

I have tried a number of different shim sums 1/4, 1/2,3/4, and 1" but I did not go in between. The part where your right is I think if I shim it to where both front joint and rear angles are correct by using the 1/8 shim or 3/16.

I have read that it does not need to be off by very much to produce the vibration that Im experiencing.

 

[Boadie]

Just finished setting all the angles so that the difference between the pinion angle and the rear shaft (two piece) is 0 degrees. The difference between the t-case flange and the front shaft is one degree. NO DICE! My next project will be to remove my lift. J/J Will be to post pictures so you will all se what Im talking about. Unfortunately I am IT challenged so this might take awhile. If any one has a step by step process on how to post these PICS let me know.

Just think if all I had to tell this crap to was my wife and my daughters, I would need counciling.

 

[Boadie]

Well, disreguard my last post. I decided to toss out all the measure this angle crap and measure that angle B.S. and did what I thought made since. If you lift your truck 3" shim the carrier bearing the same. It worked!! I can't belive it.It rides fricken nice.

 

[whatabudro]

glad you fixed it.

 

[rsjohnsn]

Congrats, I am glad you figured it out. I for the life of me had no clue what it could have been. I was about to suggest your rear pinion bearing but I glad you didn't have to go there.

Scott