Allison 5sp: Vibrations

silverballs

Silverballs
Sep 23, 2009
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Hi, Rich here, hows everybody. 2005 GMC Duramax Crew Cab long bed, vibration mostly between 30 and 52, more so when trailer and load is on. Replaced all u joints, yoke, shocks, carrier for 2 piece drive shaft, double checked, and no metal in rear. Take off back driveshaft, drive down road in 4 wheel drive, it gone.
 

silverballs

Silverballs
Sep 23, 2009
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thats next

That's the next step, but first I am going to check the carries to make sure it is in the same place as the old one, didn't hit anything, just came about, back u joint was dry, then noticed the carrier was ripped some. All weights in place, no dents on drive shaft.
 

wikdlmm

<-- OWFA
Jun 27, 2008
1,974
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san angelo
One of our truck did that same thing from55-70 an the drive shaft was out of balance an we didn't hit anything either
 

silverballs

Silverballs
Sep 23, 2009
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I have gone down the line, have to take rear end apart, I think the washer in front of the bearing is mashed from the balancer on the yoke was off by about 1/4 inch, was wobbling, I have seen rear end setting kits, is this something I want to try???
 

Diesel Pilot

Hat? Suitcase? 50 BMG?
Aug 9, 2006
1,424
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Pickerington, OH
I'm gonna follow this one.

I just started to develop a drive-train vibration that sounds somewhat similar to this. Mine starts about 60 and get's progressively worse the faster you go. But, it comes and goes. So at this point it is hard for me to nail down yet, and I'm not putting a ton of miles on the truck anyway right now.

I have a LLY too but with a single steel drive shaft.
 

SmokeShow

Well-known member
Nov 30, 2006
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Lawrenceburg, KY
My vibration starts at almost exactly 65mph-68mph and doesn't go away above that but it smooths out a little bit about 75-80mph. With all the trans. piece cracking issues I've had, I hate to even go on the interstate for fear it's gone crack something else. All joints are new or good. I'd love to pull the rear driveshaft and run it in 4wd up to that speed n see what it does.


On the trucks with a carrier bearing and two rear shafts, there is a known issue with vibration on those setups and I'm 99% sure there was a TSB about it and the fix was a spacer on the carrier bearing between it and the frame. Suppose the dline angles were out of whack and the space got the carrier bearing happier angle and all better. A friends had this issue, especially bad taking off with a load on.


C-ya
 

LBZ

Super Moderator
Staff member
Jul 2, 2007
9,905
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B.C.
I believe Mike may be talking about tapered shims between the axle and spring to change the pinion angle, but I may be wrong.....
 

Mike L.

Got Sheep?
Staff member
Vendor/Sponsor
Aug 12, 2006
15,681
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Fullerton CA
I believe Mike may be talking about tapered shims between the axle and spring to change the pinion angle, but I may be wrong.....

That is one possibilty but there are tapered shims for the center support also. Just shiming the support without checking the driveshaft angle may not work.