Quote Originally Posted by R2b View Post
Anyone know the bolt size for the engine dipstick, mine fell out and no sign of it laying around. It's tough to get to and if I have the right size my day will go a lot better. Thanks in advance, great to be here, I'm new to these boards. Oh, it's a 2004 GMC 2500 6.6 with the Allison Trans
Are you talking about the bracket bolt about 5 inches down from the top of the tube?



If so, the bolt thread is 8mm x 1.25 thread pitch. The bolt head requires a 12mm wrench. That's a dime in the photo.

Jim