2007 – Yukon Denali AWD – Drivetrain Clunk (slip yolk?)

I just bought a used 2007 Yukon Denali AWD. It has 140K miles. The truck was pretty well maintained. It’s had a lot of service done over the years. Most of the suspension was serviced – all new shocks/struts, air bags, compressor. The left motor mount was done at 120K. In general, the truck runs and drives well.

I get the thing home and start driving and then I notice this drivetrain clunk. For example, If I give it some gas, as the rpms drop and the drivetrain unloads … clunk. It seems like this might be a slip yolk related clunk (since that is a known issue with these trucks). Any help in diagnosing this would be appreciated. I have no issue with getting a new slip yolk and also changing the U-joints. I just would like to have a better idea on how to pin this down.

Transfer case pretty common I am used to it. My 05 and 06 made same clunk. I think there is a chain and sprocket update to get rid of it.

Dan_G said:

I just bought a used 2007 Yukon Denali AWD. It has 140K miles. The truck was pretty well maintained. It’s had a lot of service done over the years. Most of the suspension was serviced – all new shocks/struts, air bags, compressor. The left motor mount was done at 120K. In general, the truck runs and drives well.

I get the thing home and start driving and then I notice this drivetrain clunk. For example, If I give it some gas, as the rpms drop and the drivetrain unloads … clunk. It seems like this might be a slip yolk related clunk (since that is a known issue with these trucks). Any help in diagnosing this would be appreciated. I have no issue with getting a new slip yolk and also changing the U-joints. I just would like to have a better idea on how to pin this down.

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My opinion is you arent going to get rid of the clunk, do a good hands on inspection of all the driveshafts and if you cant find a noticeably sloppy U-joint or a yoke than you have to learn to use the pedal effectively to prevent the driveline from doing it. mine will do the same thing occasionally when downshifting to accellerate or light throttle at slow speeds on a decline. it is quite possible there is nothing "loose" or "worn out" on your denali. leave the parkbrake on wheels chocked, engine off and put the vehicle in neutral and climb underneath and rotate the driveshafts. There is an enormouse amount of for/aft play in the system, it's your job to keep it either loaded or unloaded. congrats on the new ride and get a TECH2, it should be the first thing you purchase for your new ride.

Thanks for the replies. I'll check it out. I can certainly live with the clunk if that's just what the driveline does. I do indeed have a Tech2. It does come in handy. I have a 99 Suburban and a 2006 Envoy Denali. They are both getting sold and the Yukon is the replacement.

Dan_G said:

I just bought a used 2007 Yukon Denali AWD. It has 140K miles. The truck was pretty well maintained. It’s had a lot of service done over the years. Most of the suspension was serviced – all new shocks/struts, air bags, compressor. The left motor mount was done at 120K. In general, the truck runs and drives well.

I get the thing home and start driving and then I notice this drivetrain clunk. For example, If I give it some gas, as the rpms drop and the drivetrain unloads … clunk. It seems like this might be a slip yolk related clunk (since that is a known issue with these trucks). Any help in diagnosing this would be appreciated. I have no issue with getting a new slip yolk and also changing the U-joints. I just would like to have a better idea on how to pin this down.

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The slip yoke may not be bad, it just might need greasing. Check your u-joints and the play between the ring and pinion gear on the rear axle. Also, the mounts for the front differential can also cause a motion very similar to what you are describing.

Wes, @Doubeleive and Randy, @randeez have both experienced this with their Denalis.

mine turned out to be the front differential brackets, I am sure having the slip yoke greased helped with part of it though. check your motor mounts- pop the hood up, put your foot ******* the brake and try and make it go in forward and then reverse and watch the engine movement thru the hood gap it shouldn't be moving a lot or jumping back and forth

Thanks, I'll check it out. It will take me a while. I'm getting my Envoy ready to sell. Just polished the whole thing (it's black - and now it's very shiny). That was a ton of work (too much really) but people buy cars that are pretty. Once I get that thing off to it's new owner I'll have more time to go over the Yukon.

For the time being, the Yukon seems to drive great - other than the clunk.

Dan_G said:

I just bought a used 2007 Yukon Denali AWD. It has 140K miles. The truck was pretty well maintained. It’s had a lot of service done over the years. Most of the suspension was serviced – all new shocks/struts, air bags, compressor. The left motor mount was done at 120K. In general, the truck runs and drives well.

I get the thing home and start driving and then I notice this drivetrain clunk. For example, If I give it some gas, as the rpms drop and the drivetrain unloads … clunk. It seems like this might be a slip yolk related clunk (since that is a known issue with these trucks). Any help in diagnosing this would be appreciated. I have no issue with getting a new slip yolk and also changing the U-joints. I just would like to have a better idea on how to pin this down.

Click to expand...

I got the same issue, I tracked it down to the rubber bushings on the front. It hold the front diff in place I think check it out!