The Stovebolt Site Forums The Shop Area General Truck Talk Wife doesn't like the smell....

Some things to look at:
You probably have a vented Gas tank. Coming in out of the cold the gas expands and you have gas vapors in the garage. Personally I think the new stuff smells bad compared with good old leaded regular.

Old chassis grease can get a rancid smell if it was soap or lard based. A lot of scraping and washing to get the old grease off.

gear oil can get a bad smell if it has gotten water in it and sets for a while.

Don't overlook the nasty smell of rodent urine if someone has nested since you had it outside. Especially bad if they nested in an area that heats up when the truck is started.