This is my first dump truck and I love it, but the bed does not raise while the truck is gear, only neurtral. Is this normal for an older truck or an older automatic? It is an 88 F800 with the 7.8 Brazilian mated to a 545 Allison. It works great otherwise, but it is a bit frustrating that I cannot lift the bed and drive simultaneously when I want to spread. My guts are telling me this is just the way it is...
I belive that's the way it is, it may also work if you are moving at a decent clip, but I don't think so. We have a couple of trucks like that for delivering mulch, really works fine for that, but I imagine you may be trying to tailgate out a load of stone onto top dress a driveway? There are other ways, like gaining the gate, put the body up, then release the gate latch, just be careful to not put the body up too much or you may be looking at the sky through the windshield
Yup. That way by design.
You'll get to know your chains I imagine, like @Tags said. i use chains with the pea gravel if i want it in a specific spot. Gives you time to make an adjustment, otherwise it is all over in a flash.
Well, then the good news is: nothing's broken. Ill definately have to experiment with the chains. At least it has an air latch with easy access. but yea, that bit about the sky...
that setup does not sound right. new quad axle kws -western stars even macks don`t have that problem . is it possible po had it set up to kick the pto out of gear when the trans is engaged ? was it a municipal truck?
An allison 545 drives the pto off of an output gear. So, technically, the pump is turning, when pto is engaged, while driving, but, the pump rpm is so low as to be negligible. Combined with the age of the trucks system, locked in gear 1, PTO engaged, I suspect even at 2400 engine rpm, pump output would still be insufficient. Pete Pilot, the ones you refer to the PTO is driven off the input side of the transmission, and therefore is engine rpm dependent. Units like AT545 drive the PTO off the output side, and therefore is driveshaft speed related (albeit, in neutral, the driveshaft isn't connected).
thanks @heymccall for clearing that up.
Yup, PTO takeoff is after the torque convertor. One place I worked had an old Ford T850, 454 gasser and an Allison, pto with a pump on a solid shaft driveline. Only issue we had was if you neglected to take the PTO out of gear before you launched, when it upshifted into I believe third, the ratio change was ahead of the pto and when it hit, the solid round shaft driveline would whip, yank itself out of the keyed yoke, and destroy the corner of the transmission oil pan. Happened several times, I was actually driver number three to do it, but I repaired or replaced that pan every time. Did put a warning light on the dash, but it wasn't foolproof even then.