Random Facts...Standard shift (manual) has gone for the most part but not in Class 8s. Unique Clutch Brake ..

[Joe Hogan]

If you have noticed that a trucker only uses the clutch on initial shifts from a stop. There is good reasons for this and the clutch is specifically designed to work this way.

The clutch has a brake, when the clutch pedal is depressed a friction brake is applied to reduce/eliminate transmission idler shaft revolutions. This avoids gear wear (grinding) going into initial shift into forward or reverse from a stop.

Just an interesting thought of the morning..

What Is A Clutch Brake? - Truckers Logic

The clutch brake has a circular disc with a friction surface that connects to the input shaft of the transmission between the release bearing and

truckerslogic.com

 

[Gronk]

If you push the clutch pedal all the way down to shift you are pushing it too far. The clutch brake is only for stopping the clutch plates (yes, two of them) and transmission so you can get it into gear without waiting a long time or grinding the gears. The recommended way to shift manual truck transmissions is to push the clutch in, take the transmission out of gear, push the clutch pedal back in and then put the transmission in the gear you want. One 'problem' is that the gears are non-syncro, so it is really easy to grind the gears. That was a good indication I was tired when I would miss a shift.......... That's also why the new trucks have auto shift and most don't even have a clutch pedal!

 

["EZ"]

There are more Allison Automatic transmissions in Class 8 trucks than you would believe. This new generation of truck driver is younger, more female than before, and lots do not speak English very well. To overcome the driver shortages many companies have resorted to using automatic transmissions in their fleet to make the Class 8 trucks easier to drive. I read the other day that 70% of all freight in this country moves by truck. There is a shortage of drivers right now. How many? Over a MILLION drivers short of what we need. It's incredible.

 

[AbdRahim]

They are removing the art and skill from everything. I think the brains of future generations might shrink from lack of use. Vehicles that require the development of skill to drive will be a thing of the past. Self docking truck next?

 

[Joe Hogan]

The 2021 579 Peterbilt looks like a high end SUV inside. Note the lack of a third pedal and no shifter...and cup holders

 

["EZ"]

They are removing the art and skill from everything. I think the brains of future generations might shrink from lack of use. Vehicles that require the development of skill to drive will be a thing of the past. Self docking truck next?

Actually the next thing will be the autonomous truck. Driverless, electric powered. Did you realize that there is a company that has already logged over a million miles with autonomous battery powered vehicles? It's coming folks. Get ready!!

 

[AbdRahim]

Actually the next thing will be the autonomous truck. Driverless, electric powered. Did you realize that there is a company that has already logged over a million miles with autonomous battery powered vehicles? It's coming folks. Get ready!!

I drive because I love to and enjoy having developed the skill to do what many others can. I hold on to my truck, because, though old, I can drive i9t. It does nothing automatically except shift. If I had my way I would have the largest SUV available set up with manual transmission.

 

[Gronk]

I wouldn't know how to drive an auto shift semi. I learned on a 10 speed, a 9 speed, and a 13 speed.

 

[Joe Hogan]

Here is a tutorial on using a clutch in a Class 8 truck.
Here the instructor talks about the clutch brake, non synchronized (straight cut gears) used in a truck and floating shifts (no clutch shifts). He does a reasonably good job for the novice student.

 

[Joe Hogan]

And shifting without a clutch

 

[FL-JOE]

A buddy of mine who owns/leases several trucks back to FedX told me that there are tons of drivers on the road today that do not speak English and can not back up. He said some will get to a terminal and if backing up is required they will park and go inside to get someone to come out to back in their truck for them. These are the folks we are sharing the road with......eekkkkkksss

 

[Joe Hogan]

A buddy of mine who owns/leases several trucks back to FedX told me that there are tons of drivers on the road today that do not speak English and can not back up. He said some will get to a terminal and if backing up is required they will park and go inside to get someone to come out to back in their truck for them. These are the folks we are sharing the road

I have seen videos of these guys playing bumper trucks at truck stops. And just drive off..... their irresponsibility is incomprehensible....


Hopefully the Cool factor of being a Big Rig driver will return at some point and improve the driver pool. You can still make a decent living if you are careful as a O/O.

 

[AbdRahim]

A buddy of mine who owns/leases several trucks back to FedX told me that there are tons of drivers on the road today that do not speak English and can not back up. He said some will get to a terminal and if backing up is required they will park and go inside to get someone to come out to back in their truck for them. These are the folks we are sharing the road with......eekkkkkksss

Supposed professionals? Fakes. This should not even be tolerated.

 

[Joe Hogan]

Some interesting details, I didn't realize that the straight cut gears in heavy trucks are unique to this application. Even the vaunted M22 Muncie Rock Crusher, from my hot rod days, used Helical gears.

Helical Gears | KHK Gear Manufacturer

Helical Gears have teeth with a helix angle for higher torques and noise reduction. KHK produces various standard/special helical gears.

khkgears.net

Straight cut gears in cars were saved for Track only vehicles.

This said, the straight cut "Spur" gears are noisy. Possibly another reason Class 8 trucks are going Auto Shift, to quiet the truck interior and reduce the sound emitted from the truck.

Spur gears: What are they and where are they used?

Spur gears are a type of cylindrical gear, with shafts that are parallel and coplanar, and teeth that are straight and oriented parallel to the shafts.

www.motioncontroltips.com

Eaton 18 Speed

 

[Gronk]

Another thing the class 8 transmissions do not have are synchro rings that allow you to shift without matching RPMs to vehicle speed like the automotive transmissions have. Here is a decent explanation of what they are and what they do: Improve Shifting Syncro Ring Kits Manual Transmission - drivetrain.com

 

[Neal]

Several posts removed. Keep it kind and on topic. Thank you.

 

[Joe Hogan]

Here is a recent article on the switch to Automated Manual AMT and Automatic (Torque Converter) transmissions. The numbers as stated earlier are heavily in favor of AMTs.

Automatic efficiency: Why fleets are shifting from manual transmissions

Over the past decade, the trucking industry has discovered that automatic transmissions are better than humans at reliably and accurately performing precisely timed motions.

www.fleetowner.com

Automated Manual Transmissions Become Industry’s Popular Option - TT

If a customer wants to drive one of the Class 8 trucks in Ryder’s commercial rental fleet, it will have to be one with an automated manual transmission, which shouldn’t be a problem because that’s what most customers want.

www.ttnews.com

 

["EZ"]

I started selling commercial trucks in 1993. I sold International and Ford chassis into the wrecker industry. At the time International offered 13 pages of transmissions to choose from for class 7 and 8. You could really screw up a truck and make it almost unusable if you picked the wrong one! The book was thicker than a phone book for a major city. Shortly thereafter we got computers to spec the trucks with and the program would help guide you and not let you make so many mistakes.

Back then EVERY TRUCK I ordered was a straight shift. A few years later Allison Transmissions had a contest to see who could sell the most automatic transmissions. I sold over 1000 Allison Automatic transmissions that year! So, as a prize Allison Transmissions took me and my wife to the Bahamas for a week! From that year on almost every truck we ordered had an Allison automatic transmission in it. It was an EZ sale to the truck owners because they were all tired of having to pay for clutch replacements because of drivers that didn't know how to use a clutch. The Allison completely eliminated that expense. Today, the problem is even worse with inexperienced drivers, especially in class 8 tractors. Those guys have to be away from home for at least a weekm at a time and get stuck sitting in their sleepers waiting for loads to come available. After a while that $50k per year salary doesn't seem so attractive any longer. Both my brothers were class 8 tractor trailer drivers. I've heard all the horror stories first hand. It's not a good life style and if you talk to my wife who has been in the medical field for 30 years she will tell you that professional truck drivers do not live nearly as long as the rest of us for a variety of reasons. I'm glad I chose to SELL commercial trucks rather than drive them!

 

[Joe Hogan]

Here is an interesting discussion about double clutching and why it is preferred over "Floating Gear shifts".