Just thought I'd post the experience I had today replacing the D side motor mount on my friends 2007 Denali XL......if you're interested.

First of all, I'm located in Northern California......biggest rain storm of the season and the lowest temperatures (Low to hi 30**) so far this winter.

First off, needed a small bottle torch to warm up the lug nuts so I could remove them. They were so tight due to the bitter cold that, using a pipe on a 1/2 inch drive breaker bar wouldn't get the lugs loose. Lug nuts came off easily after adding a little bit of heat.....removed the tire.

Removed the 10mm bolts which secure the heat shield to the exhaust manifold, and then removed the shield.

Unbolted the front driveshaft at the U-joint (four 11mm bolts) and moved the front end of the shaft towards the transmission.

Used a 1/2 inch drive breaker bar with a long extension and a 'swivel' joint and a 15mm socket to remove the three bolts which fasten the motor mount onto the frame.

I removed one alternator mount bolt and screwed it into a threaded hole on the side of the cylinder head......up near the front of the cylinder head, next to the coolant temperature sensor........(removed the temperature sensor connector so it wouldn't interfere with the movement of my lift chain).

I removed the engine cover for extra lift clearance.....just pop up the corners then wriggle it towards the front of the vehicle.

I then hooked the end of my engine hoist to the alternator bolt I mentioned above and lifted the engine as high as it would go without hitting the firewall.

Then I used 3/8 drive ratchet in conjunction with a 15mm socket and an assortment of socket extensions.......(long, small, medium, stubby extensions) to remove the four bolts which secure the motor mount to the engine block........this was very frustrating!!!!!

After that, the motor mount was loose but "trapped" in a small area......I maneuvered the motor mount around in various positions until I could gain access to a pair of 14mm nuts located on the top of the mount. I removed both of those nuts and the top plate of the motor mount was removed from the vehicle.

I then removed the motor mount heat shield.

I then moved the mount towards the location of where the front drive shaft bolts onto the differential and pulled it out from the bottom of the vehicle.

Installation is in reverse with the exception being that wire wheeled (cleaned) the bolt threads and added thread lock compound to the bolts and nuts.

NOTE: The three motor mount bolts for the frame are longer than the 4 bolts for the engine.......don't mix them up.......the longer frame bolts will bottom out in the engine block holes without securing the mount to the engine. ARRRGH!!!!!! Should have clicked some pics to upload, but I didn't. Coulda, woulda, shoulda.

Sounds like a major project. Well done. Cold or not, if the lug nuts were that hard to get off they were over-torqued.

Yeah.....I think they were over torqued to begin with......that idea plus the fact that the daytime temperatures were hovering right around 35 degrees contributed to the lugs being tightly locked in place. The major part of the job was removing the bolts which secure the motor mount to the block.....you're basically working blind, and the other difficult part was maneuvering the mount assembly around it'* confined space in an effort to gain access to the top plate bolts so that I could disassemble the mount (four parts lower main mount, insulator, heat shield, top plate).....once I got the mount minimalized, it came out fairly easy.