RCTaylor

Got the truck back today they replaced all the front differential bearings. I had the chance to look at the ring gear and pinion when they removed it and they both seemed fine with no chips or damaged teeth. I checked to bearings they removed one seemed really rough but it is hard to tell. I still feel I hear the noise but can't be sure that now that I have had the issue I am being too critical. If anyone has a similar truck do me a favour and put it in Auto and see if there is an increase in drive line noise. I really notice if i am simply traveling with no torque or coasting, and add power and i hear the increase. I want to be fair but never noticed that happening before they left the oil out. Any help is appreciated.

I don't know who is using my name, but these posts are not mine. It is correct that i have a 2021 Denali and the address is correct but not my Posts!

Yesterday, they took the truck for a drive returned said there was no noise! I got the Manager back into the tuck and took him for a drive. He initially said that the noise was common when in 4 wheel drive, I told him that not for my truck! He immediately said they will pull the differential and replace the bearings! Hard to believe but they stand emphatic that the Dealer in Ontario did not add fluid! I asked him then why did the noise practical disappear after! I have spoke with a couple mechanics locally and they feel, the new bearings will probably do the job and that it is likely the ring gear and pinion will be still fine because I did not drive it any distance in all wheel. I guess I will know after they replace the bearings February 2nd. I appreciate all the feedback and will let you know!

You are thinking exactly as I am! I have grown up with heavy forestry equipment and trucks, and common sense says that if after they put the oil in the Diff and the noise has almost gone away, I have damaged bearings and possibly ring gear and Pinion! I am certain that when I take the truck to the Dealer who replaced the seals and told me over the phone when the second dealer discovered no oil that it is likely a U joint, I am expecting nothing good! There are few things we can do to these new trucks beside change the oil and grease them and that is how I found the leak in October when they replaced the seals. I know they are going to say they filled the Diff, but the second dealer found no leaks! I think they will not be willing to admit that mistakes happen and the Tech failed to complete a crucial step! I'll let you now what I find out tomorrow!

This is Richard Taylor from New Brunswick, and I did not make these posts! My last post was about my front Diff

I guess I will find out what they plan Thursday afternoon! Ill let you know. Thanks

I have a 2021 GMC 2500 Hd Denali, and in mid October my local Dealer replaced seals on the Front Diff under warranty. Just before Christmas I had a need to engage the Auto 4 wheel drive and there was a serious growling noise or vibration. I took it to a Dealer in Ontario and they found the front Diff was 2 liters low. They filled it and reduced most of the noise, but I can still hear it! I plan on keeping this truck for a long time, my last 2500 was 14 years old when I got rid of it. The local dealer from talking to him believes it must be a front U joint! I have about 90K on the truck and soon out of warranty. My local dealer says that the front Diff is always turning and therefore it could not have been from the low oil! There is no sound in two wheel drive. I am concerned that it has affected the ring gear and or pinion! Any input? Thanks Richard Taylor

I have no idea! The first time I was running about 40 MPH but since it is only when slowing. My only concern is, if it could cause other problems. in the transmission. Possibly worried about nothing I put about a 1200 km per week so it should not take long!

.Has anyone had the recall completed for the Transmission Control Valve? I recently had mine done and now am experiencing rough down shifting just prior to making a stop. As I exit a highway and head to an intersection the truck is shuddering as it drops the last three or four gears. This never happened before this repair so just wondering. Maybe something else. I have about 122,000 km. on the truck but this is since 120 K when the repair was made.