2010 yukon denali awd driveline/tranny clunks???

[10YukonDenali]

i just purchased a 2010 Yukon Denali 6.2 as a second vehicle for snow and towing a boat. after driving it a week buying from a private party I've noticed it clunks when i shift it from park-reverse or reverse-drive or park-drive or drive-reverse. I've heard it can be normal for these rigs but i rode in another one the other day that seemed quiet. also I've noticed that it will down shift from third to second while slowing down hard on occasion. nothing extreme but enough to raise concern. tranny shifts great other than that. also I've noticed if you're coasting and the revs are low and you stab the throttle a little bit you can feel a clunk. rig has 120k and the guy seemed like he took care of it and didn't seem like the type that would hammer on it. not sure if its tranny or a differential would like some opinion. THANKS!!!

Edited October 11, 2019 by 10YukonDenali

[davester]

I would suggest first checking out your u-joints, and the center support bearing if you've got a 2-piece driveshaft

[swathdiver]

1 hour ago, 10YukonDenali said:

i just purchased a 2010 Yukon Denali 6.2 as a second vehicle for snow and towing a boat. after driving it a week buying from a private party I've noticed it clunks when i shift it from park-reverse or reverse-drive or park-drive or drive-reverse. I've heard it can be normal for these rigs but i rode in another one the other day that seemed quiet. also I've noticed that it will down shift from third to second while slowing down hard on occasion. nothing extreme but enough to raise concern. tranny shifts great other than that. also I've noticed if you're coasting and the revs are low and you stab the throttle a little bit you can feel a clunk. rig has 120k and the guy seemed like he took care of it and didn't seem like the type that would hammer on it. not sure if its tranny or a differential would like some opinion. THANKS!!!

Check your u-joints but also pull the driveshafts and grease the splines inside the slip yokes.  This is the usual cause of clunks.  The transmission is operating normal, keep the fluid clean, clean fluids in everything and she'll treat you good for a long long time.

 

A BlackBear tune will change the way the transmission behaves for the better.

[muddkatt]

3 hours ago, swathdiver said:

Check your u-joints but also pull the driveshafts and grease the splines inside the slip yokes.  This is the usual cause of clunks.  The transmission is operating normal, keep the fluid clean, clean fluids in everything and she'll treat you good for a long long time.

 

A BlackBear tune will change the way the transmission behaves for the better.

Do not grease the yoke on 4x4.  There is no grease retainer inside the tail end of the transfer case.  Grease can leach into the transfer case and contaminate the fluid.  Only ATF should be used on 4x4 2007 onwards.     

[swathdiver]

1 hour ago, muddkatt said:

Do not grease the yoke on 4x4.  There is no grease retainer inside the tail end of the transfer case.  Grease can leach into the transfer case and contaminate the fluid.  Only ATF should be used on 4x4 2007 onwards.     

I've not heard this before, my owner's manual even says to use grease on the slip yoke splines.  It's synthetic grease too.  Huh.

[Black02Silverado]

Interesting that this is a slip yoke issue still.  I know GM had issues back in 2002 like on my 2002 Silverado and the fix was to change out to a Nickle  plated slip yoke, which they did on mine and it fixed the clunk.  

[muddkatt]

2 hours ago, swathdiver said:

I've not heard this before, my owner's manual even says to use grease on the slip yoke splines.  It's synthetic grease too.  Huh.

FYI, this is from a post by  MS3DALE back in 2010.

 

Subject: Do Not use Slip Yoke Grease from Bulletin #09-04-17-002C on 4WD Vehicles

 

--------------------------------------------------------------------------------

GM Customer Care and Aftersales 

 

 

*URGENT - DISTRIBUTE IMMEDIATELY*

 

 

DATE: November 4, 2010

SUBJECT: Do Not use Slip Yoke Grease from Bulletin #09-04-17-002C on 4WD Vehicles.

MODELS: 2007 – 2009 Chevrolet Silverado 1500 Series

 

2008 – 2009 Chevrolet Avalanche, Suburban, Tahoe 1500 Series

 

2007 – 2009 GMC Sierra 1500 Series

 

2008 – 2009 GMC Yukon, Yukon XL 1500 Series

 

Equipped with 4WD (RPO NQG, NQH)

 

TO: Chevrolet/GMC Dealers

ATTN: Service Manager and Parts Manager

 

A new grease, part # 19257121 (in Canada, 19257122), was recently released for lubrication of slip yoke splines to repair a condition of a bump feel or clunk noise at stop or from launch on the vehicles equipped with 4L60 Automatic Transmission (RPO M30) and 2WD. Please see Bulletin # 09-04-17-002C for details.

 

Do not use the new grease for lubrication of slip yoke splines on 4WD vehicles. The output shaft in a 4WD transfer case does not have a grease retainer to keep the grease from migrating into the transfer case and mixing with the fluid inside. The new grease is not compatible with the Automatic Transmission fluid used in the transfer case and can cause damage if mixed. Lubricate the splines on 4WD vehicles with Automatic Transmission Fluid, P/N 88861003 (in Canada, 88861004). Please refer to Bulletin # 09-04-21-003B for repairing the bump feel or clunk noise condition on 4WD vehicles.

 

 

[10YukonDenali]

ill start with u joints. Thanks for the feedback

[swathdiver]

3 hours ago, muddkatt said:

FYI, this is from a post by  MS3DALE back in 2010.

 

Subject: Do Not use Slip Yoke Grease from Bulletin #09-04-17-002C on 4WD Vehicles

 

--------------------------------------------------------------------------------

GM Customer Care and Aftersales 

 

 

*URGENT - DISTRIBUTE IMMEDIATELY*

 

 

DATE: November 4, 2010

SUBJECT: Do Not use Slip Yoke Grease from Bulletin #09-04-17-002C on 4WD Vehicles.

MODELS: 2007 – 2009 Chevrolet Silverado 1500 Series

 

2008 – 2009 Chevrolet Avalanche, Suburban, Tahoe 1500 Series

 

2007 – 2009 GMC Sierra 1500 Series

 

2008 – 2009 GMC Yukon, Yukon XL 1500 Series

 

Equipped with 4WD (RPO NQG, NQH)

 

TO: Chevrolet/GMC Dealers

ATTN: Service Manager and Parts Manager

 

A new grease, part # 19257121 (in Canada, 19257122), was recently released for lubrication of slip yoke splines to repair a condition of a bump feel or clunk noise at stop or from launch on the vehicles equipped with 4L60 Automatic Transmission (RPO M30) and 2WD. Please see Bulletin # 09-04-17-002C for details.

 

Do not use the new grease for lubrication of slip yoke splines on 4WD vehicles. The output shaft in a 4WD transfer case does not have a grease retainer to keep the grease from migrating into the transfer case and mixing with the fluid inside. The new grease is not compatible with the Automatic Transmission fluid used in the transfer case and can cause damage if mixed. Lubricate the splines on 4WD vehicles with Automatic Transmission Fluid, P/N 88861003 (in Canada, 88861004). Please refer to Bulletin # 09-04-21-003B for repairing the bump feel or clunk noise condition on 4WD vehicles.

 

 

Much obliged Muddkatt!  Haven't heard of anyone having problems after having done it but certainly won't recommend this course of action or do it myself anymore.  

[10YukonDenali]

had my mechanic look at it he said u joints are all good and the clunk when going to park/reverse etc is coming from the front diff. not sure just to roll it and turn the music up or take it in to a trans specialist and see if the diff needs work

Edited October 12, 2019 by 10YukonDenali

[swathdiver]

9 hours ago, 10YukonDenali said:

had my mechanic look at it he said u joints are all good and the clunk when going to park/reverse etc is coming from the front diff. not sure just to roll it and turn the music up or take it in to a trans specialist and see if the diff needs work

Often a front diff clunking problem is the bushings in the mounts, not the differential itself.  

[Rodney Jeffries]

On 10/11/2019 at 2:51 AM, 10YukonDenali said:

i just purchased a 2010 Yukon Denali 6.2 as a second vehicle for snow and towing a boat. after driving it a week buying from a private party I've noticed it clunks when i shift it from park-reverse or reverse-drive or park-drive or drive-reverse. I've heard it can be normal for these rigs but i rode in another one the other day that seemed quiet. also I've noticed that it will down shift from third to second while slowing down hard on occasion. nothing extreme but enough to raise concern. tranny shifts great other than that. also I've noticed if you're coasting and the revs are low and you stab the throttle a little bit you can feel a clunk. rig has 120k and the guy seemed like he took care of it and didn't seem like the type that would hammer on it. not sure if its tranny or a differential would like some opinion. THANKS!!!

My 2010 Yukon Denali 6.2 clunks about 3 times right after putting the truck in drive from park when I pull off. After that it operates normal except for an occasional hard down shift when coming to a stop.. any ideas what this could be? I had the tranny serviced and no visible damage.