You want to drive a Road Ranger gearbox, WHY?
A LOT of people think they can operate a road ranger but even experienced drivers for the most part, still are not driving them properly.
Years ago we didn't have a choice, this was our only option, the industry wanted to have bigger trucks and cart more weight.
The Eaton Fuller Road Ranger was the most popular because it was the only designed driveline that would accommodate motors in excess of 400hp without sustaining damage. Now the gearboxes have improved so much that you can now do the same heavy haulage job with a 730hp Scania which has an automatic gearbox!
So first let's just talk about what exactly a Road Ranger is?
Well Road Ranger is only a brand name, but it is often used to describe a non-synchromesh gear box or sometimes called constant mesh transmission. Non-synchromesh transmissions are actually one of the earliest forms of the manual transmission.
It is thought to have been invented by Louis-René Panhard and Émile Levassor in the late 19th century and was used in most motor vehicles up until around the 1940's I believe.
This type of transmission offers multiple gear ratios and, in most cases, reverses. The gears are typically engaged by sliding them on their shafts (hence the phrase shifting gears), which required careful timing and throttle manipulation when shifting, so the gears would be spinning at roughly the same speed when engaged. If not engaged correctly the teeth would refuse to mesh. These transmissions were commonly called sliding mesh transmissions or sometimes crash boxes, because of the difficulty in changing gears and the loud grinding sound that often accompanied a change.
Over time technology improved and the synchromesh transmission was introduced.
Synchromesh gear boxes were designed to change gears based on engine performance and other velocity indicators, delivering torque to drive wheels.
Transmission gears are always in mesh and rotating, but gears on one shaft can freely rotate or be locked to the shaft.
Unlike the non-synchromesh transmissions these transmissions have synchronizing mechanisms (called cone and collar synchronizers) that are designed to keep gear dog-teeth from being broken off, meaning the driver is not required to double pump the clutch in order to change gears.
Upon conception this gearbox was primarily used for light vehicles as its popularity did not transfer to heavy vehicle for some time after. This was due to the fact that because of the improvements to horse power in heavy vehicle motors, the synchromesh gearbox couldn't handle the large amounts of torque produced.
In short the gear boxes would end up getting blown to pieces. Today this gear box is found in all cars and 90% of heavy vehicles manufactured within the last 20 years.
So why do we still use Non Synchromesh gears boxes?.....
Stuffed if I know.
Years ago it was understandable, synchromesh and automatics simply couldn't handle the heavy loads, but these days not only are the synchromesh gear boxes just as good but the technology even for Automatics are good enough as well.
What seemed to have developed in this time is a sort of stigma towards synchros and autos, as well this mentality that if it's not a road ranger it's not a real truck...
These days the only trucks that really use road rangers are the American brands such as Kenworth, Freightliner, Western star's, Ford's and Mack's.
Even these brands though are now primarily building Automatics. The European and Asian brands such as Mercedes, Scania, Volvo, Iveco, MAN, Isuzu, Hino, Mitsubishi, DAF and most UD's have been using synchromesh for a long long time.
The only real reason I can understand companies persist with the road rangers is because the non- synchromesh manual transmissions are mechanically simpler and more easily manufactured with fewer moving parts than automatic transmissions. They require less maintenance and are also easier as well as cheaper to repair due to their mechanical simplicity.
Bit of a catch 22 if you ask me though, sure they are easier to fix but they are also easier to break. Someone who isn't using a road ranger properly can stuff a clutch brake in less than a day. Meaning they have the potential to require a lot more frequent maintenance due to their complexity in use. But let's not get into a pissing contest.
OK so now we know what a road ranger is, let's talk about how to drive one.
A few important factors you need to know.
Half clutch, timing, rev range, road speed.
First thing is, you only need to use between a quarter to half of the clutch when changing gears. If you press the clutch too far you will activate the clutch brake.
The clutch brake is there to slow down the top shaft (input) of the gear box, which is only needed when you are stopped. This feature is designed to stop the top shaft from spinning allowing the slide gear to move along and engage without grading, meaning if stopped you can easily drop it into a starting gear.
If you activate the clutch brake by pressing the clutch too deep while driving, the top shaft cannot be slowed down due to the high speed which can cause the clutch brake to blow to pieces!
We don't need to break the drive and instead only put weight on it and change the gears by matching the revs.
Practice this without the motor going and do so until you are brain dead, the more you practice the better it will stick to your sub-conscious.
The clutch will need to be depressed twice in quick succession. First compression of the clutch is to pull it out of gear; by briefly having it in neutral it slows down the bottom shaft (output) enough to match the speed of the top shaft before trying to mesh them together.
The second compression of the clutch is now to put it into the next gear smoothing without grading.
Changing down gears:
Changing down gears follows the same principle as changing up except for one added step.
After you compress the clutch for the first time putting it into neutral, you will then need to tap the accelerator to speed up the top shaft (lift the revs to around 1500rpm) in order to match the speed of the bottom shaft for a smooth change to the lower gear.
After accelerating you will immediately need to compress the clutch for the 2nd time to put it into the lower gear before the revs drop down too far.
Revving too low or too high when changing down means the top and bottom shafts are not spinning at the same speed and will fail to mesh. Crunch! Crunch! Crunch!
Timing is crucial; as you depress the clutch once, you pull the gear out, on second clutch compression, you put the gear in. Count 1-2 on every change. This should be the time it takes between each gear change, don't rush it!
Remember to hold weight on the gear stick (called pre loading) before engaging the clutch, this way it comes out of gear at the same time as the clutch is pressed and into the next gear at the same time as the 2nd compression. This pre loading techniques helps to eliminate room for error which occurs when trying to find gears and double pumping the clutch at the same time.
A common mistake drivers make when learning is either their hand moves faster than their foot, or the foot moves faster than their hand.
The correct revs will vary depending on make and model but as a general guide try not to lose more than 200 rpm when changing gears.
The low gears should be changed at 1200 rpm and the high gears changed at 1700rpm.
Drive up to 1200rpm, gear out and let revs drop to 1000rpm to drop gear in. With the high gears drive up to 1700rpm then place gear in when revs drop to 1500rpm. For beginners this is so hard to do, so as with the clutch, practice with motor on revving up to 1200rpm and letting off to 1000rpm you cannot let it drop under 1000rpm otherwise gear will not select.
Road speed needs to be monitored constantly. You must learn what speed the truck is doing in every gear.
You can do this slowly once you picked up how to double clutch. When learning, start this training with high range 5th, 6th, 7th, and 8th. We will use same revs as we described in last paragraph.
While driving in 5th get your revs up to 1700rpm change to 6th then look at speedo.
You should be doing about 44 km/ph. Next gear is 7th so drive up to 1700rpm change gear and take note of what speed you are doing in this gear.
You could be doing say 56km/ph, do the same with 8th gear and so on.
Now as we change down the gears take note of what road speed you drop to for an efficient change.
Now we have a speed range in each gear. Remember this speed range next time you knock it out of gear and are having trouble recovering.
All you should have to do is quickly look at the speedo, see what speed you are doing then bring your revs up and select the closest gear to that speed. Easy!
Driving a road ranger is not a simple task, it takes a long time to master and might not be for everyone.
If you are thinking about getting your heavy vehicle licence do some research and find out what gear box you will need for your particular job. Don't just listen to the advice from your brother in law.
Years ago it was better to get the road ranger straight away so you never had to worry about it again (which is still true), however these days they are becoming few and far between, especially amongst HR classes.
If you haven't had much experience with trucks before, it might work out to your benefit to start on synchromesh and get some experience before attempting the more complicated gear box.
You can always upgrade it later usually at minimal cost because you are now only learning one new thing as opposed to 20!
This upgrade can even be done when attempting you next licence upgrade such as stepping up to MC.
For most this is the preferred method as training and assessment can be completed as a competency assessment (training course) rather than another assessment with the department of transport.
Weekly we deal with a class of people upgrading their HR or HC licence up to the MC class.
During this time we spend a small part of a day talking about our experiences and swapping war stories. Just about every week there will be a fella tell the same story: "I remember when I was going for my HR licence, every told me to go for road ranger. It ended up taking me 6 lessons and I still failed my first test. In the end it cost me around $2,000 and took about 12 weeks in total. And you know what? I've never driven (one) since!"
If your set on learning road ranger it pays to get some experience operating heavy vehicles first, go for a drive with a mate (if you have them) and get some experience when it's not costing you money in lessons.
Then once you have gotten used to operating vehicles with larger size and weights, then learn it properly with a driving school. For example most people who drive road rangers don't use the clutch at all when changing gears; well the clutch is there for a reason so if you don't use it during your test you're not going to pass the test.
If you don't need a road ranger licence straight away maybe save some money by going synchro first.
They are much easier to get use to and much more comfortable to drive. If you going to drive trucks 12 hours a day for the rest of your life trust me you want to be comfortable.
The saying goes it takes a man to drive a Kenworth but it takes a real man to admit he would rather drive a Volvo.
Give me a Volvo any day.
Disclaimer- I am aware this post is likely to generate a fair bit of debate especially from all you American band loyalists, this is not only expected but encouraged. Feel free to voice your opinion or raise your discussion in the comment section below.
From the series: I got bills to pay- Stories of 55 years on the road with Alan Rutland