GM 6500 gas job.


Very first truck I ever drove, tandem dump with a 427 gas engine, 5+4 trans, probably 34000 lb rear ends. This or a similar spec'd ford was a typical dump truck back in the day. Makes me laugh when I hear you need 500 hp in a dump these days to get around.

I got a p/t job when I was 15, cleaning it up and greasing it, checking air in the tires and tune ups on the engine. I got hired because I knew how to do a basic tune up and I knew more about that than the owner who was also a welder. He introduced me to welding, we re-skinned the box on that one and a few others.

Never really got real good at the 5+4, it was two transmissions, two sticks which was OK on the flat ground, but climbing a steep hill with the gas engine it was hard to down shift it fast enough to end up crawling up the hill.

Steve Frazier

Staff member
Most of the local use trucks I remember as a kid in the 60s were gas jobs, and the majority of them were Internationals. Both the 6 cylinders and V-8s had a peculiar whine to them, the fan blade, to where you could recognize an IH just by its sound. I remember the V-6 GM motor had a unique growl to it, I've read that came from the timing gears.

I've driven a couple trucks with two transmissions, definitely an experience. I got pretty good with them, but if you missed a gear, forget it, I had to stop the truck and start over. I was never able to get back in gear without having the tranny sound as if it was going to fly apart.

You have to wonder how they ever got by with less than 200hp lol!


Staff member
Back in the 80's I drove a TMS100 Grove 12 1/2 ton hydrocrane, had a big International inline 6 cyl gasser, 5 x 3 trannies. The big pistons in that thing really had a thump to them, and my God did that thing love gasoline! The old gas hog finally laid down and we fitted a little 6 Cummins in it, made the crane a different rig.

As for the main and aux trannies, I've drove a bunch of them, Fuller, Spicer, 5 x 2, 5 x 3, 5 x 4, MacK Maxi-Torque, the trick is to never (while driving) get both trannies in neutral at the same time, you'll loose your center shaft rotation then. If you're grading a hill at the time, as Steve said, forget it, stop and regroup. But if you're rolling on rather flat ground or downgrade, don't panic, allow the engine to come to idle, push the clutch in and engage the main box in 2nd gear. Gently raise RPM to 2000, go for third, just like you would be while driving. Once you get the main box to a gear that you would normally have it at the speed your going you can then work on getting the aux box back in a slot.


Well-known member
We still run a few gas burner dump trucks. A 1962 GMC 5500 with the 401 V6 engine,5&4 transmission ,& 34,000 lb rears. And a 1966 chevy c-60 single axil with smallblock 350 & 4 speed trans with 2 speed rear.Both still pretty good old trucks.I used the C-60 this week hauling dirt at a jobsite.People can talk big horsepower all they want,but pound for pound the old c-60 will pull as good as any truck around.Only thing I can figure is the low geared rear end is perfect with the smallblock 350 pulling at the 3,250 rpm range at highway speed.I can put 7 tons in the bed of the old truck & stay rite with the new big rigg tri & quad axils hauling 21 tons.I have a buddy that still uses a 1976 chevy c65 tandem axil with 427 & 13 speed as a back up truck in his farming operation.It is using some oil & fouling plugs .He's going to bring it over this fall & have us overhaul the 427.That will be fun.I still like working on the old trucks.:D


Staff member
The first dump truck I drove was a 1968 C50 with a 366 and a 5 sp trans, no 2sp. It was an ex-muni unit from the City of Birmingham that my dad bought from a dealer who obviously bought it direct from the muni as the city decals were spray painted over. It was originally army green but he painted it red in the shop.

This old girl had been rode hard and put up wet. The heat didn't work (A/C yeah right...:rolleyes:), the glove box was gone, there was a spring on the passenger side bench seat that would poke you in the ass if you didn't have a piece of cardboard stuck underneath what was left of the seat cover and there was a hole in the floorboard around the gear shift big enough to suck anything in and onto the road - never had to clean it out though...:p

I rode quite a few miles in that truck on the main roads as I wasn't legal driving age, drove many a miles underage on the back roads.:cool: Different day, different time.


Staff member
And how many "Oh Sh!t" items went down that hole?
I lost count...there's was nothing worse than buying a ice cold drink on a hot day and have it slide off the seat or the dash, (cup :rolleyes:) hit the floor board and line up perfectly to slide down the hole and go skidding across the other lane.:p