2Yrs Unsolved Binding/Knocking Suspension During Sharp Turns

[swathdiver]

Yes; I posted the page from the OP's 2002 Denali manual. Context matters.

Refresh me memory on these 800s. So they have a 2-speed transfer case without Auto and one with, correct? Then they also have an AWD case? I wrote down all the RPOs and the TC names but cannot find it, along with the pictures of the dash controls. Come to think of it, 4 options back then? Help me! LOL

 

[Fless]

Refresh me memory on these 800s. So they have a 2-speed transfer case without Auto and one with, correct? Then they also have an AWD case? I wrote down all the RPOs and the TC names but cannot find it, along with the pictures of the dash controls. Come to think of it, 4 options back then? Help me! LOL

I don't know all that much about the options, and I'm sure there are more than these:

NP2 - 2 speed manual shift
NP3 - Single speed AWD - NVG149
NP8 - 2 speed AUTO (New Venture Gear 246) -- this is what I have in my '04 Hoe - takes Auto Trak II blue fluid
NR4 - AWD -- (Borg Warner) BW4482

I'm sure there is also probably a single speed 4x4 transfer case.

EDIT: corrected NP8 model number from 248 to 246 (fat fingers)

 

[nick0789]

Just something super quick you can check:
I had some binding and popping on my Tahoe a while back. Long story short, one of the frame-side bolts for my passenger upper control arm wasn’t fully tight.

While I agree that the transfer case is more likely to be your issue than a loose nut/bolt (I never had bucking), it is worth double checking that everything is actually torqued down, at least.

 

[Wunderground]

@nick0789 Noted ... thanks for your comment. Since I know the shop owner, I'll be able to have a look underneath while the truck is up for the TC fluid change. I admit, I also suspected loose bolts at one point. Appointment is on Tues. Dec. 21st.

 

[Fless]

One other suggestion is to check and inspect the front diff mounts. If it hasn't been done yet, both engine mounts and the tranny mount should be checked, too.

 

[Rocket Man]

Ok guys, as far as the fluid for the transfer case….drumroll please. The 2002 Yukon Denali came with RPO NP3 (@Wunderground check the sticker in your glovebox to verify) which is the NVG149. The owners manual does indeed state to use Dex III. However the service manual states to use Auto Trac II. If you do an internet search you’ll find a bunch of confusion, just like when you search for the answer regarding the differential fluid for the G80. The consensus seems to be that the AutoTrac II is an improvement over the DEX III for this transfer case, and the service manual reflects this. IMO either will be fine. I have been using the AutoTrac II for many years on mine with zero issues. I have 170k on it currently and with a supercharger and other power adders it gets worked hard. The trans has grenaded, the front diff has grenaded (long story there), I have broke u-joints but the NVG149 is still going strong and the fluid always comes out clean.

 

[Rocket Man]

I don't know all that much about the options, and I'm sure there are more than these:

NP2 - 2 speed manual shift
NP8 - 2 speed AUTO (New Venture Gear 246) -- this is what I have in my '04 Hoe - takes Auto Trak II blue fluid
NR4 - AWD -- (Borg Warner) BW4482

I'm sure there is also probably a single speed 4x4 transfer case.

EDIT: corrected NP8 model number from 248 to 246 (fat fingers)

You forgot the one the OP has- NP3, the NVG149.

 

[Fless]

You forgot the one the OP has- NP3, the NVG149.

Thanks for that! I didn't forget it, but I didn't have the deets on it. I updated post #22.

 

[Wunderground]

Thanks for the research @Rocket Man , always appreciated.. I'll have a talk with the shop owner.

 

[Rocket Man]

Thanks for the research @Rocket Man , always appreciated.. I'll have a talk with the shop owner.

I researched it back when I first went to change the fluid in mine, and remembered there was some confusion. Looking forward to what the shop says.