wills and ways

A day about the letter "t"... Tuesday, Terry, Trunnions

Today Terry came up to help me replace trunnion bolts. Now, if you don't know what trunnions are, well, you're in good company. The trunnion is the probably the most important part of an entire dump truck. It is a steel rod as thick as your ankle and it supports the entire business end of the truck: all the weight the rig labors to carry is transfered thru the trunnion to the back wheels--all 8 of them.

Holding the trunnion to the truck is the trunnion cap which is, in turn, secured by 8 bolts--grade 8, 7/8's thick times 4" long.

First getting the old ones out. No way to unbolts them. They've been permanently rusted, fused, and frozen together for many years. They've gotta come off with the oxyacetylene torch. Problem is it's very cramped quarters down there in trunnion territory and when you've got a torch going and sparks are flying it's guaranteed that they're going to find away to the place you don't want them. In my case today it was my nostril and my neck and my ear and up my shirt sleeve. Not all at once, mind you--separate events. Separate sets of cursing and trying to wriggle myself out fast from under the truck to get at what's on fire and burning against skin.

Got the bolts off, Terry shows up and we get to work. The replacement bolts, shiny and new in the box, are supposed to be torqued to 1200 ft lbs. So guess how you put 1200 pounds of force on a bolt wriggling around under a truck axle. The pro's have an expensive 1" drive air wrench (that's not me). We did it with a 10 ft piece of pipe and some easy Math. 120 pounds of force 10 ft out on the end of a wrench extension equals 1200 ft pounds.

Tomorrow I'll fabricate the frame rail reinforcement and bolt it up. Then Dr. Brown will be ready to go to town. Or go down the road to haul the Sea Mule section back down to the bottom.