FIRST 4 GEARS

As long as you can get it rolling without lugging the engine too much or slipping the clutch a lot then you can easily start on 4th. Some of that will have to do with the ratio of your rear end, but if your truck is spec'd with an 18 speed I highly doubt it has a high geared rear end, so I would imagine you should be fine.

 

Look on door jam 3.55, 3.08, etc, it is gear ratio. Like the others have said skip gears; I do it a lot; bobtail or empty. Will not hurt tranny to skip some gears even the high side if your not lugging engine or putting undo stress on clutch.
Over rev is bad also; should be a safety built in engine for this but it also sucks on fuel usage.

 

If you've got an Eaton 18 speed, it doesn't matter if it's in a Mack, Petercar, Cornbinder, Freightshaker, Kenwhopper, etc...it is going to shift the same way. Why? Because it's the exact same transmission. Watching videos on how to shift a Mack transmission won't necessarily help you with your Eaton.

And for what it's worth, my Mack 18 shifts beautifully. The only time they shift like #### is when you have a ####ty driver shifting like ####.

 

That is weight rating, tag you need will read: Axle ratio.

 

It sounds to me like your problem is that in the low low gears the truck does not pick up enough road speed to get into the next gear.

The problem becomes even more difficult if you're going even slightly uphill because the truck then wants to slow down even more and it becomes more difficult to get into the next gear.

So if you need to pull out in that lower gear and you're going uphill sometimes you have to just maintain that gear and get up the hill until you can shift.

If the truck is headed downhill you can pull out in a little higher gear because the momentum of the truck is going to automatically want to head down the hill anyway and at that point you can probably even skip a gear or gears if you need to.

On level ground you have to decide what gear you need to pull out in that will not slip the clutch. Lower gears are good but you probably have to shift more quickly.

It might sound funny, but instead of winding the truck up in the lower gear trying to get more Road speed, sometimes it's better to use less RPMs so that the RPMs will drop down faster and you can get into the next gear faster because if the truck road speed slows down faster than the RPMs come down it's harder to get into the next gear, if that makes any sense. Especially when you have a lot of close ratios like in an 18 speed transmission.

 

Trucks do not generally like city very much.

Im assuming you are leaving a red light, drive two blocks and stop at the next light. You hardly got into maybe 4th before you are there and have to stop again.

One symptom of that is when you put in the clutch to stop, your rig breaks tension on the power line and rocks side to side usually to the left I think kind of a big rock. That tells me you are sort of working a little bit too hard in that cab.

If this is a manual. You know that 1600 shes already wanting the next gear. Let's go. Already literally pulling it's rears off wanting to GO. NOW.

IF you go the other way on the RPM gauge say 1300 you find that you can sort of move around the low range without too much rocking, drama, power or any of that. You more or less EASE your way through the block quietly in one gear or another. If you had a bunch of green lights you might take her into 5th high. Which I think is about 25 or so. Not too shabby.

Most trucks have engines big enough now with beef where you can pretty much ease off the light in say 3rd or 2nd when loaded. Once you ease the power down lightly with your right foot, the rpms come up gently. Not straight to 1600+ Take a heartbeat or two to lift your right foot BEFORE engaging that clutch to make a shift up. You will find her settling just so and your clutch goes in easy and click into the next gear without the problems.

Low range is really hard to be smooth in. You are essentially dealing with maybe 4 gears plus low and reverse that have HUGE mechanical ratios in terms of ability to alot of work in either watts or Joules very quickly in terms of power against your inertia and load.

There is another form of shifting called progressive.

Instead of being in gear number one WINDING ALL THE WAY to 1600 breaking loose into 2nd... what you do is you let her come up to about 1400 or so, take second. Until 1450. Take third. until 1500. Next thing you know you are walking clean away from the winder you left behind.

 

I think it's more or less a matter of you just getting the rhythm down in between gears. When I was teaching my son he was doing the same thing at first, no problem getting it out of gear but would sometimes miss the next one so he figured out a word or something to say in between gears and picked it right up