6.2Creedmoor

The 2007-2013 Sierra Denali's had this issue as they were AWD and the front driveshaft angles were out of spec after lifting more than 2". Same issue I am having as AWD is essentially the same thing as running in 4AUTO. Not technically but for arguments sake of this issue it is. The only difference between the 5.3 and 6.2 (regarding this issue) were the yokes as the 8 speed had a different yoke than the 6 speed but that is for the rear driveshaft. Depending on how your front carrier is clocked and what that does to your front driveshaft angles after the lift will determine if you are going to experience any vibrations when running in 4WD.

I had the shop measure my front driveshaft angles and due to the clocking of the front diff carrier along with the lift it was out of spec for a u/joint driveshaft. We dropped it to measure and have reached out to RoughCountry to see if the previous CV driveshaft for the 2007-2013 Denali's would work. Still waiting for them to produce a schematic for measurements. Worst case I will have to have one custom fab. Either way we determined it is the front driveshaft angles causing the vibration.

Pretty limited options for the 6.2 due to the difference in yokes on the 8 speed versus 6 speed. There are a couple that are out there and then a number of custom shops that will fab one for you. Price is between $400-$600. I have the shop sourcing one now and I will let you know what they come up with.

Nope, other than the TCC shudder

As in factory and not the GM Genuine (Chevrolet Accessories) trailering mirrors (non-power folding)?

This probably only had the three screw posts versus four? If so, do you think the vibration could be shored up with drilling the fourth screw post?

Anyone have any insight into the vibration I am getting in 4 Auto and 4 Hi after installing a BDS 4" lift? The transfer case was smooth as butter prior to the lift. The vibration is almost like a groan that can be felt in the transfer case upon acceleration between 10-30 mph. The shop is stating that I will need a CV (dual cardan) front driveshaft as the pinion angle and prop shaft angle has changed and the u/joint angles are no longer in phase. Yet, it seems there are plenty of others running 4" and 6" lifts that don't require a CV front driveshaft and have no vibrations in 4 Auto and 4 Hi. And then there are the others that are stock and have the same vibrations.

Anyone have any insight into the vibration I am getting in 4 Auto and 4 Hi after installing a BDS 4" lift? The transfer case was smooth as butter prior to the lift. The vibration is almost like a groan that can be felt in the transfer case upon acceleration between 10-30 mph. The shop is stating that I will need a CV (dual cardan) front driveshaft as the pinion angle and prop shaft angle has changed and the u/joint angles are no longer in phase. Yet, it seems there are plenty of others running 4" and 6" lifts that don't require a CV front driveshaft and have no vibrations in 4 Auto and 4 Hi. And then there are the others that are stock and have the same vibrations. ?

Is it possible to configure the cargo lights to come on in reverse but not when unlocked from the key FOB? The high output cargo lights are great for backing in a trailer at night but they are blinding when walking up to the truck and loading the kids in the back seat. I believe the Max Tow - NHT package has the ability for the cargo lamps (when pressed) to come on when in Reverse, Park, or Neutral. But since I have a non-NHT then my cargo lamp only comes on when in Park. Or is it possible to configure the cargo lights on a non-NHT to operate as the NHT to come on (when pressed) in Reverse, Park, or Neutral?

It seems with so many sellers of aftermarket towing mirrors I was hoping to get a thread going of member reviews. There are so many options and sellers at all ends of the price point (Trail Ridge at IAAuto, American Trucks, Boost Auto, etc. and then on the other end of the spectrum you have the Amazon and Ebay sellers). Yet, we know the aftermarket mirrors are not being manufactured in US for a specific retailer and are being sourced overseas and/or sold via private label (Trail Ridge). I suspect the fully optioned power folding mirrors being sold at the higher end of the price point could be sourced for much less if a side by side product comparison could be done to determine which of the lower priced mirrors being sold on Amazon and Ebay are getting sourced and sold at the higher prices. I am hoping that some members can share their reviews to help since a side by side comparison would be difficult and fairly costly.

@pgamboa When you are building a custom PNP mirror harness for towing mirrors can you add the following mods or would these be required to purchase from someone like boost auto: Rear facing lights to act as Cargo and Reverse Dual function signal and running lights Cargo lights in drive

What are your thoughts on now having the TrueTrac installed? I am in the same boat as I am converting my 4x4 6.2L 8 spd 9.76 over to 3.73 yet everything is back ordered. I am currently geared in 3.23 and my shop is saying the 917A732 is the correct part number for 3.42 and higher without having to use a spacer since it has the correct carrier break and we are moving to the 3.73 gears. Do you happen to remember if you used the 917A732 or 914A538?

Correct, I will not be using the BG ATF but will be supplying the shop with Amsoil SS ATF.

Stupidly, I can't believe I am going to poke the bear. I am here to learn but need to understand the concepts being shared. But I don't think the milk glass analogy applies here. Unlike the milk glass, the transmission is sealed and fitted with effectively an inlet for filling (by removing the oil cooler lines) and an outlet for draining (by using the level set plug) while using a pressurized medium to exchange the volume of fluid based on a finite capacity of 11.4 quarts. Under Pascal's Law and the concept of a siphon if we are displacing 11.4 quarts under pressure then we should only need 11.4 quarts to replace the volume of fluid lost. If the viscosity is different across certain manufacturer's base oil then other applied concepts of fluid dynamics such as dynamic viscosity would come in to play and that would shed some more light on this question and your point about reaching a specific dilution. What am I missing here?

Yes, dealer is recommending the Mobil 1 HP LV ATV HP Blue Label flush but they are stating the TSB is not covered under warranty (bumper-to-bumper or powertrain) as it is a maintenance item. It's odd as others have stated this has been done under warranty. And after hearing that it hasn't permanently fixed anyone's issues I am going to go the Amsoil SS ATF route first as I have heard better results. My TCC shudder issues are very minor but still present and I am at 55k with no previous transmission fluid service done by the previous owner that is on record.