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patio furniture breaker
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Discussion Starter · #1 ·
i had my truck at the dealership getting an alignment after i did the drop last weekend. i had them check the driveshaft angles and stuff too. they told me my angle at the rear end is 0, so i need a 3-4 degree shim. however, driving it i dont notice any vibrations. only slight raod vibrations, but its at all different speeds. how bad would the vibration be?

i found one shop locally that has a 3.5 degree shim, but its just the shim. do i need a new bolt for the spring pack? i found a 'kit' on djm's website that comes with a new bolt for the spring pack.

the shop foreman told me that the shim would fit over the top of the threads that are already there, but what about my flip kit bracket? its the old style flip kit, so it has no adjustable pinion angle.
 

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GMFS slowest truck :read:
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theres a few different types of shims (aluminum vs steel, bolt in vs slide in). you want steel bolt in shims. The slide in ones just slide over the top of the spring pin head, but they cut down on the amount of the head inside the spring perch hole by a good deal so not too many people care for them...yes, they work without a hitch, most of the time, the bolt in style is much better.

as for spring pins...most parts stores sell them...but id recommend just getting a 3/8" g8 bolt thats long enough, either throw it on a lathe or toss it on a grinder and round the head so that it will fit in the spring perch.

and if you aren't noticing any vibes, don't touch it. matts step dad and i both had the exact same set up, suspension wise, at one point with shackle flips and all...his stepdad had no vibes, i had nothing but vibes.
 

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patio furniture breaker
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563 Posts
Discussion Starter · #3 ·
and if you aren't noticing any vibes, don't touch it. matts step dad and i both had the exact same set up, suspension wise, at one point with shackle flips and all...his stepdad had no vibes, i had nothing but vibes.


see, thats the thing, i dont think i have any vibrations. i notice a few low speed vibs, but there at all different speeds, never the same range of speeds everytime. how bad would to vibrations be?

i ahte to second guess the mechanics (cause i'm not one), but if theres no vibs, why do i need shims? they told me my angle at the rear end is 0. if i added the shims, would it hurt anything? just maybe casue vibrations to say that its out of allignemet with the shims?

i'm so confused with all this stuff.

plus, i can't find anybody locally that has the shims. i found them from truckshop.com for like 25 bucks shipped ground, and thats for the DJM 4 degree kit that comes with the longer bolt for the sping pack.
 

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O deg on the d-line is bad because the U joint caps are not turning at all in relation to the cross. This results in a u joint that will dry out or wear out prematurely. Only use a 2 deg shim.
 

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GMFS slowest truck :read:
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5,501 Posts
O deg on the d-line is bad because the U joint caps are not turning at all in relation to the cross. This results in a u joint that will dry out or wear out prematurely. Only use a 2 deg shim.
yeah i forgot about that. they do need to have SOME angle to them to keep the needle bearings lubed.
 

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What ends up happening besides drying out is the individual needles begin to wear depressions in the cap & shaft because the torque is all applied in the same surface. normal travel is typically only about 2", this isn't enough to change the pinion angle much at all, perhaps 1 deg. and that is only 10% of the time. there is more piniion angle change under heavy acceleration or decceleration. Either way it is a "premature" wear, not something that is going to go out in 5K mi.
 

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patio furniture breaker
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563 Posts
Discussion Starter · #7 ·
they told me to get 3* shim, but i cant find any. just 2 and 4. so its too little or too much. they said 4 would be ok. but you guys said 2.

thanks for the help. i think i'm just going to order the DJM 4 degree kit and wait for it to get here. i'll just take it real easy on my takeoffs and stops.
 

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patio furniture breaker
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563 Posts
Discussion Starter · #8 ·
ok, i just ordered the DJM 4 degree kit from truckshop.com in anaheim california. its shipped ground,so it should be here in a week or so.


hopefully this will fix my problem. i'll install it and take it back up there and have them check the angles again.
 
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