The Stovebolt Site Forums The Parking Lot Big Bolts can you leave the truck in high gear

I have not seen this written anywhere,Can you leave the truck in high gear when not having a load {meaning all the time }or is it better to just use high gear when in forth gear.Thanks..

I leave my truck in "Hi" gear,since my 2-speed switch cable binds half the time. I can start out in 2nd,on a hill,with no problem.(NO LOAD). Some will disagree,but (on a hill),if I start out in "Granny Hi",by the time I shift to 2nd,the truck is almost at a complete stop,anyway. One trucking company I worked for,set the trucks in "HI",then removed the button and cable! Too many guys that didn't know how to shift,would "blow" the rears! I LOVE the 2-speed for loads,though!

Most likely, you are referring to high-range on a 2-speed rear-end/rear-axle truck?

Many old trucks had 2 speed instructions on the dash. Eaton advised trucks to be parked in Low Range. We did this because the E-brake was almost worthless and we used the lowest gear we had for parking. When we drove empty, we started in Low range and shifted into high range once we got to hi gear. Trucks were so underpowered that we had to split shift them with a load. Learning to shift a 2 speed was part of learning to drive a truck and most of us learned between the ages of 12 and 14.

yes two speed rear,I have got a ways to go on the split shifting! Lol! Thanks for the replys...

The vacuum "shifted" 2-speed Eaton rear-end in my 54/55 GMC 2-ton "defaults" to low range if vacuum is lost, and when the truck is turned off.

The experts can comment, but with my 2-speed axles (one electric, one vacuum), they don't seem to care which range they are in (the engines care ... ), but if I don't use them regularly, even unloaded, they will stick. So I try to use them all the time.

Interesting note: The M-817 has single speed Rockwells but the old timers say you can split shift it using the two-speed transfer case. So I tried it ... Let's just say that I won't be trying THAT again ... ever.

As Tim notes above, vacuum shift rear ends tend to shift or "default" to low range when the truck is off and vacuum is lost. The danger of this is when your truck has a drive-line parking brake with the drum just behind the transmission. When the vacuum bleeds down and the rear end drops out of high and before it engages low, you are not in any gear. Thus, the truck could roll if on an incline. That is why you will read and hear about leaving it parked in the low range. My COE has parking brake cables to the shoes in the rear, so it is not a problem. My Diamond T has a two speed rear end and drive-line parking brake and the manual instructs you to leave in the low range.
Kent

Unless you engage the drive-line (propeller shaft) "parking brake" when you park the truck?

The driveline parking brake is on the back of the transmission.
So the rear axle could slip into neutral as it falls out of high gear. In which case the truck may roll away and the driveshaft need not turn.

So it would be wise to follow the operators manual/instructions and park the truck with axle in (usually) low gear.

My two speed diff. on my 46 always stays in high,except when I am rolling around corners,shifting it to low range, works great with no grinding. Down shifting to 3rd when I'm rolling grinds the gears no matter how careful I am.