By Colin Wood
Jun 23, 2020
Most modern passenger cars and trucks can come with anything from five- to 10-speed transmissions. Semi-trucks, on the other hand, are often equipped with 18-speed transmissions–like the one on this 2007 Peterbilt 379.
Sure, transmissions in semi-trucks function a little differently from ones found in passenger cars and trucks, but it's still pretty impressive to say you know how to shift a manual transmission with 18 gears.
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6/23/20 11:56 a.m.
That was pretty cool. I always wondered how those big monster transmissions worked.
6/23/20 12:51 p.m.
One on my favorites
6/23/20 12:54 p.m.
Another favorite
6/23/20 1:00 p.m.
My grandfather had a couple of these Macks. At one point I knew how to do this:
https://m.youtube.com/watch?v=RaDxMVeLbgo
6/23/20 4:28 p.m.
In reply to Datsun310Guy :
I was driver/operator of a M 246 wrecker as a mechanic in the Air Force in the 60s. It had the 5 spd with splitter like this. Driving the old PA turnpike with a truck on the hook required 100% concentration.
6/23/20 6:53 p.m.
Geez, and I thought driving a normal automotive 6 speed m/t well was a thing!
6/23/20 7:08 p.m.
In reply to outasite :
I'm sure somebody today can do all that and still text. LOL.
6/23/20 7:13 p.m.
In reply to Datsun310Guy :
No doubt, I had a student that could text with his phone inside his hoodie pouch. With one hand.
6/23/20 8:56 p.m.
One of my high school friends used to run heavy equipment for a local excavation contractor. One of 10 wheeled dump trucks was an International with a 549 cid gas engine that had a 5 speed main and a 4 speed auxiliary transmission. Split shifts were done with your left arm through the steering wheel and left hand on the main stick while your right arm shifted the auxiliary. It was quite impressive to watch. I drove it once on a side road, took about 7 shifts to get up to 30 or so. They eventually repowered the truck with an International DT 466 diesel and whatever transmission came with it out of the donor truck when parts for the gas job started getting unobtainium. Not as cool to watch but way more useful.
They had a Mack dump as well, I remember riding shotgun in that a few times moving equipment between jobs. The exhaust stack was right behind the passenger seat and would shoot sparks if the engine had a good load on it, fun at night. No power steering, he got a workout driving it. That one had a some variation of a road ranger transmission so the splits were done by an air operator on the auxiliary controlled by a switch on the side of the main stick if I’m remembering correctly.
6/23/20 8:57 p.m.
I saw a vid on youtube years ago of an aussie driving a transmission that had like 4 switches or maybe a switch with 4 positions on the gear stick. Very unique trans that I can't find again.
The question I've always had about 18 speeds: How do you know what gear to shift down to after slowing? Like I can be going 80 in the bmw, brake hard down to 55 and know that 4th won't overrevv but will also be a good power gear to get back up to 80.
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