Driveshaft vibration 6" lift on 2 door Tahoe

[MikeyHustle]

Hey guys,

I just finished lifting my 98 2 door with a BDS 6" lift. But because the 2 door Tahoe driveline is so short it's at a very steep angle. And it seems to cause vibration. What have you guys done to fix this?

Thanks in advance!
Mike

 

[cmc76]

i am just throwing this out as i had a minor vibration after doing u joints. another member told me to undo the shaft and spin it 180 degrees. Got it from another member here, but cant recall who. In short, that was all it took, no more vibration.
Costs noting, so i would start there.

 

[bowtiefreak]

As stated above, make sure everything is working is in good shape. Tapered blocks, shims...all things that my be needed to phase the U joints correctly. I now run a CV shaft from Tom Woods Custom. That and some 12* shims got me right on my 2 door

 

[ColoradoMike99]

Digging up an older thread.... I just did a 4inch lift Pro-Comp lift on my 99 2-door with Auto-trac 4x4. Now, I can hear/feel the driveshaft spinning. Especially noticeable at 10-15mph when everything else is super quiet (no wind noise, no tire noise etc.) Coasting, braking, accelerating doesn't seem to matter. I pulled the front driveshaft, assuming that was the issue. STILL makes the noise! WTH. there was no noise at all before the lift. Ive never heard of a rear driveshaft issue with only a 4inch lift. Some lift manufacturers say Tahoes with auto-trac will need dual cardan front driveshaft, but none say anything about issues in the rear. What could this noise be? How do I isolate the issue? It is much faster than wheel speed - has to be somewhere in driveline?

 

[wjburken]

Digging up an older thread.... I just did a 4inch lift Pro-Comp lift on my 99 2-door with Auto-trac 4x4. Now, I can hear/feel the driveshaft spinning. Especially noticeable at 10-15mph when everything else is super quiet (no wind noise, no tire noise etc.) Coasting, braking, accelerating doesn't seem to matter. I pulled the front driveshaft, assuming that was the issue. STILL makes the noise! WTH. there was no noise at all before the lift. Ive never heard of a rear driveshaft issue with only a 4inch lift. Some lift manufacturers say Tahoes with auto-trac will need dual cardan front driveshaft, but none say anything about issues in the rear. What could this noise be? How do I isolate the issue? It is much faster than wheel speed - has to be somewhere in driveline?

View attachment 234424

If you don’t have them installed, might try putting in a couple shims to rotate your rear axle a little for a better driveshaft angle.

https://www.summitracing.com/parts/...MI5Izk0ryd5gIVKSCtBh20MwVFEAQYAiABEgJ7OfD_BwE

 

[ColoradoMike99]

Thanks for the response. Still trying to figure this out. The rear blocks are angled, so the angle from the diff is pretty subtle. Looks steeper at the transfer case. I though these needed to be equal? Found some slip in my rear diff and u-joints so cleared all that up. It’s improved but there is still a weird sound when I let off the gas above 35. -like a fluttering. Not constant but does it every time. Hard to describe but seems like a high speed rattle that phases itself out. I might try mounting a go-pro under there to see it in action.

 

[OR VietVet]

Before you go much deeper you need to check for problems at the pinion bearing and gear. To qualify this statement I ran shops and had guys/girls come in that wanted to go fast and throw lots of money at engine mods to increase speed and performance but never gave it a thought to address any weaknesses in there steering and suspensions to handle the increased power.

Remove the rear diff cover and look for any problems in there and check, with driveshaft removed, for pinion bearing noise and play. Check gear lash. Make sure the pinion yoke is in good shape and not sloppy on the pinion gear splines. Your angle from the diff may seem subtle but that is your opinion. Before tear down get an angle gauge and post here what the angles are at the front and rear of the driveshaft.

 

[Cantrepeat]

As stated above, make sure everything is working is in good shape. Tapered blocks, shims...all things that my be needed to phase the U joints correctly. I now run a CV shaft from Tom Woods Custom. That and some 12* shims got me right on my 2 door

My shaft's a *****!

Great products. I've run his double cardan driveshafts on my Jeeps in the past.

 

[ColoradoMike99]

Sorry for the delayed response, been slammed with work so the Tahoe has been sitting, but planning to jump back on it soon.
Thanks for the response. All of your input is super helpful.
Yeah, I regeared recently and that is all brand new front and rear. I'm thinking the only thing left is to try a dual-cardan rear shaft and or play with the angle. Since the rear blocks were angled, I assumed everything was set up to function correctly.
Maybe for the 4-door. lol.