Growling noise in 4hi-Duramax w/ Superlift

[kool-aid]

The truck is a 2006 Chevy crewcab Silverado Duramax. It has a 5-6" Superlift with all the extras including the Bilsteins and extended front driveshaft. It runs great and is supersmooth in 2HI but when I shift into 4HI at speed or am around 30mph or above there is a growling (maybe whining noise) coming from the front, worse some say when turning. The sound has been conformed by my buddies in the truck and it does go away when shifting back to 2HI.

The store that installed the lift says its fine, no metal to metal wear from the driveshaft or that. I rarely use 4WD , only usually when towing my three place , any ideas?

 

[switchback]

Any other issues? GM's will make a howling type noise from the front diff when in 4wd or auto. Are your tires all worn envenly? Stupid question, but have you checked the fluid in the diff & transfer case or changed them (depending on mileage)? Did this just start after the lift was installed?

 

[H2SNOW]

Id say that you got some bearings or ujoints eating themselves up front from the t-case forward

 

[pgsledder]

cv joints, diff, tires theres multiple things that could be wrong. take it to the dealer and get them to check it.

 

[Dogmeat]

I've got an 05' 2500HD, no lift, 8.1L/Allison ... I've never noticed any kind of 'howling' whatsoever from this truck at all, save for the normal Allison sound....definatley nothing when in 4WD. I'd say whoever put your lift on screwed something up and something's in a bind.

I'd go check out www.fullsizechevy.com

that's probably the best GM truck site on the internet if you're looking for lifted GM truck advice.

 

[Barnes]

I would say check the front driveshaft since thats what they changed. They might have gotten lazy with the joints and dislodged some bearings. You could also try www.thedieselplace.com. Even though its a diesel sight, the guys on there know everything from drivetrain to profesional detailing.

 

[skibreeze]

Unless your truck has manual hubs, I highly doubt that it is u joints or the diff. They are spinning all the time, the t case simply couples the front and rear shafts. Is it possible that the t case isn't shifting properly.

I would jack it up by the axles to be able to run it and track down the noise.

 

[hilinerider]

you have to check fluids regularly, all these new pickups have a pump in the transfer case, if the seal is out inbetween the trans/transfer case it will pump the oil in the tranny and run the transfer case dry, been there done that, the tranfer case will work but make a growling noise, if you pull the stick on the trans and its a tad overful i would check the transfer case

 

[cek]

I'm sure you checked this but when I lifted my 05 the front driveshaft rubbed just a little on the exhaust. It's was hard to find because the sound echoed throughout the drivetrain. Just something to check.

 

[Himark]

It could just be a coincidence with the lift but I would look at the bearings in the front diff. GM has a notorious problem with them siezing. I have a shop floor stacked with take out front diffs under warranty.

 

[kool-aid]

The noise is a harmonic vibration coming from the driveshaft. Apparently the driveshaft needs to be balanced and if that doesn't correct it, a new driveshaft will have to be built w/ the yoke closer to the transfer case.

 

[augerin]

If the angle on the u-joints is to sharp it will make a growling noise also. Had this problem on a toyota I had lifted in high school. It was especially noticeable when off throttle coasting.

 

[prowrench]

i have installed many of these lifts and when the new gmt 800 truck came out in 99 we has issues with the frt diffs, when you lift the ifs you have to cut the top mount off the ft diff and bolt on the lift companies half moon shaped bracket which in turn rotates the ft diff forward, lowering the fill plug hole & level, so you dont get enought diff fluid in the diff, will last awhile but will fail with low milage aroung 15-20 k. the fix is to pull out the ventilator and fill. once you rebuild the ft diff that is. most likely smoked the side bearings and spiders. i do believe superlift had a bulletin on this, i learned the hard way, rebuilt way too many. sorry to hear that

 

[Without A Trace]

First of all was that 5 to 6 inch lift or five foot 6 inch lift?