# Echobit flip with zero rate angles

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by FL84K5, Mar 14, 2003.

1. ### FL84K51/2 ton status

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I'm running an Echobit flip with an ORD zero rate to give me around 6 inches of lift. Im having very bad vibrations. What degree shims are you guys using with this setup? A CV shaft is out of the question for probably another 6 months.

2. ### BorregoK51/2 ton status

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Pick up a protractor or angle finder for a few bucks and you can figure out the angle you need. Measure the angle you have from the t-case to the driveline at the u-joint, then measure the angle from the pinion to the driveline at the u-joint on the other end. Those two angle should be equal plus 2 degrees on the pinion side of the shaft which points the pinion nose down a little lower to accomodate for axle wrap. If your pinion is directly inline with the shaft, add 2 degrees to the angle at the t-case side, and this is how much you need to shim the pinion nose down, and the correct degree of your shims. If your pinion is slightly lower than inline with the shaft, subtract the pinion to driveshaft angle from the t-case angle and then add 2 degrees. If your pinion is higher than inline with your driveline then add the pinion to driveline angle to the t-case angle plus another 2 degrees and you again have the degree shim you need. With all the combinations of frames, t-case, tranny, suspension, and axles that fit into any year chevy truck... its the only way to get it right the first time.

3. ### 84_Chevy_K10Banned

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How come my driveshaft doesn't vibrate, despite the fact that I have a negative pinion angle? I've got your flip, and I was thinking that I was going to have to mess with angles...but my shaft doesn't vibrate at all, and my transfer case is not lowered either!

4. ### Waxer1/2 ton statusAuthor

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That in my opinion comes down to variances between everyones vehicles. I made a comment a week or so ago that everyone who runs a shackle flip (regardless of which type) will have their own sets of issues to deal with, and some not at all.

I installed the ORD shackle flip, no shims, and have had zero vibrations. Just recently on my last outing I banged up my rear shaft a bit and now I am feeling something back there. Nothing flip related, its more of a out of balance issue now.

The same holds true to everyone here tho. Some of you are going to have to deal with vibes, and others aren't. Some will have to shim down, others won't. Way too many variables here.

1. Leaf spring rate
2. Leaf spring age (decay of rate)
3. Ujoint condition
4. Differences in lift amounts
5. Balanced or out of balance driveline
6. Condition of Pinion bearings (ones that are shot like mine will definitely cause vibes).

Just some of the variables.

5. ### bigjbear1 ton statusStaff MemberModerator

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You also have more WB = more forgiving on angles.

6. ### Poohbair1/2 ton status

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I am running the Echobit kit w/ the 57's and I mounted them backwards... This stretched the wheelbase about 6 1/2". I run a 203 case that is not lowered, and I am not running ANY shims in the back. I don't know if my pinion angle is good or not by measurements, but it doesn't vibrate. The truck has alot of vibration, but I think most of that is from the unbalanced 38's. Oh, the driveline is also a homebrew cut down unit on a chopsaw, then welded back together w/ a pint of ATF inside the shaft (Fluid Balancer).
Not sure if you can see much from this pic, but it might help someone...

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