300+ rebuild

[Freightrain]

9 minutes ago, mowerman said:

always nice to ask questions constantly about oils,,,, i will be doing the same thing soon with a triplex,,,,i would have just put 90 weight in it,,,bob

I got some Sheaffer oil for my Triplex.  Go back to my build and I have it posted.

[BottleHauler84]

2 hours ago, Freightrain said:

I asked the shop I got this from and he explained it to me why not to make a phony 18 spd.  I could have had him do the bearing upgrade for me then but I don't have any real reason to need splits on the low side.

Right. Yeah I actually did the upgrade on a RTLO20913A thats in one of my trucks. Its a simple upgrade and its not terribly expensive to be honest.  It just consists of changing the splitter gear that incorporates the extra bearing, splitter gear, reduction gear and mainshaft (output). 

Here's the parts you change to build the auxiliary box of the 13 to the 18 specs. Then you can split it. Like you said though Larry,  not really needed unless your doing heavy work in my opinion.  

[Joey Mack]

Great info Bottlehauler...  👍 

[tjc transport]

we have an 18 speed in the 2000 Kenworth W900.

i only split the low side of trans once, just to show someone how it was done.

[Joey Mack]

When I was a younger youngster, (1999/2000) I drove a '97 RD Tractor with a 400 and a Mack 18 speed.  That truck out pulled the new to us, E-Techs with the 427's and 13 speeds.  I did split the low side a lot because I was pulling a dump trailer that was off road as much as on road and grossed over 100,000 lbs quite often...   ( according to the Maine State Police) who liked to weigh us A LOT !!!!!

[Geoff Weeks]

I grossed 160K-170K several times with a 13 spd and never felt a need to split the low side. I could have used a lower starting gear, but once I was rolling, it didn't take much to get up on the high side. This was before I had 2 spd rears in anything.

May be if I was in steeper terrain, but I doubt it even then. 

Low side is mostly below 25 MPH. If you can't pull below 25  without splitting, then you likely should stay in a lower gear until you can shift without splitting. 

Plenty of times I wished I had a lower 1st or reverse than a 13 provided but never wished I had smaller jumps between gears on the low side.

My guess that is why we didn't see 18's until 2spd and aux transmission started to become a thing of the past. 6x4 or a 13 with 2 spd would be my choice for hauling heavy.  

[Mark T]

You guys talking about an old 13 (RTO) compared to an RTLO 18 are talking about trucks from back when a 4.11 axle was concidered "high" (fast axle)   These newer trucks with taller gears like 3.36s or even faster (?) the ability to split low range makes more sense and the RTLOs have lower ratios in the 1st and 2nd gears that are even jumps going up (or down) progressively for launching a truck geared that fast.  That's talking about the sticker, not the " low " over by your leg and back.  An old RTO with 3.36s would be almost like shifting a Mack 5 speed in low range.  (well, not that extreme, but less than ideal anyway)  A good amount of the newer trucks are set up with fast axles and an Ultrashift , then road speed is cut off on the top. It'll do it's thing as it's programed. Most guys driving a truck like that ????  they just call it an automatic and hold the steering wheel. I have to admit, I'd like to be around to hear Larry power shift'n that Mack with a straight pipe on it

[Geoff Weeks]

The "old 18's and the RTLO's have about the same low ratio, but I do agree the new have more even steps, in the 17%- 21%. range. I had one truck that had 3.46's and a old 9, Not quite 3.36's but close enough.  It would still be out of low by 25 Mph or so.

 While I have driven a few electronic engines, I never owned one so don't have a whole bunch of long term seat time in one. That said, less RPM isn't always better, in comparison to what others report, my older mechanical had at most a 1mpg "penalty" but that was a few years ago and may be different now.    

[Freightrain]

We're rollin now!

Good enough to roll it out into the driveway so it can be lifted by friends crane.

The plates sticking forward will hold chains going up to spreader bar and will get the chains ahead of the firewall.

The front will have chains hooked to the front motor mount trunion using eyelets.  Yea, it will be in the way of setting it down in the truck but will deal with jacking it up slightly and removing nuts and eyelets at that point.

It's hard coming up with a way to hook onto anything up front.  Besides using a strap around the crank/pulleys.  I can't fudge it too much as it has to be able to be used the day the crane is here.  Can't find out afterwards that I don't have a way to pick it up.  I didn't want to have to remove anything off the motor like I did with pulling the 237.

 

[Mark T]

23 minutes ago, Geoff Weeks said:

The "old 18's and the RTLO's have about the same low ratio, but I do agree the new have more even steps, in the 17%- 21%. range. I had one truck that had 3.46's and a old 9, Not quite 3.36's but close enough.  It would still be out of low by 25 Mph or so.

 While I have driven a few electronic engines, I never owned one so don't have a whole bunch of long term seat time in one. That said, less RPM isn't always better, in comparison to what others report, my older mechanical had at most a 1mpg "penalty" but that was a few years ago and may be different now.    

They're within a quarter turn to the lower in an RTLO, but, the split is there, where it's not in an old 13. You'll see the difference a lot more with a faster rear axle. Then there was th first 18s. They had a little lower in the low side and only a tiny overgear. They were back in the late '80s and weren't around very long.

[Mark T]

Holy cow, that's some nice work on the roll job.

[Freightrain]

Thanks.  Took some hard head beating to come up with that.  So simple it took me a long time.... 😆.  They don't swivel but no real need, I can just jerk it a bit and it will aim right out the door.  The casters were a loaner from a friend so I didn't complain.  I was telling him last week at lunch about what I was doing and he says " I have new set of them at the shop, I will go get them.

[tjc transport]

3 hours ago, Geoff Weeks said:

I grossed 160K-170K several times with a 13 spd and never felt a need to split the low side. I could have used a lower starting gear, but once I was rolling, it didn't take much to get up on the high side. This was before I had 2 spd rears in anything.

May be if I was in steeper terrain, but I doubt it even then. 

Low side is mostly below 25 MPH. If you can't pull below 25  without splitting, then you likely should stay in a lower gear until you can shift without splitting. 

Plenty of times I wished I had a lower 1st or reverse than a 13 provided but never wished I had smaller jumps between gears on the low side.

My guess that is why we didn't see 18's until 2spd and aux transmission started to become a thing of the past. 6x4 or a 13 with 2 spd would be my choice for hauling heavy.  

i used to roll between 174-220,000 pounds with a 237 and mud stick DM 800 rolling 14-24 rubber on both truck and trailer.

the truck and trailer alone were 87k and change, then add the D8K with full tank of fuel and a 14 foot "U" blade, and i was rolling rite shy of the 220K i was legal for with the "S" tags on the trailer. 

i was also 13' 11" on the blade, 1 inch off my 14 foot wide permits. 

when i had the D8's or 235 excavator on the trailer i never went over 25 MPH. it;s kinda hard stopping that much weight. 

[Joey Mack]

Wow!!

[Geoff Weeks]

I was rolling between 45-55 mph with those loads and enough axles and brakes. Takes a lot to move along at those speeds. Steam sterilizers from Chicago to Jackson Mo.  Long, tall, wide and heavy. 

[Mark T]

That's gonna be an entirely different truck between the engine transmission and power steering. (not sure why that's just sink'n in to me) You gotta be like a kid on December 23 about now.

[Freightrain]

Ya, the anticipation is really building up now.  I just want it done!!  😆.

[Geoff Weeks]

The thing that would make that truck jump out from the rest at a truck show is the tip turbine aftercooler.  I think it would have been fine with the triplex or just about any transmission given the loads he is going to pull.

It will have a unique sound pulling, and there aren't all that many tip turbines on the road anymore, or those that know what they are. I think you'd have to look a long time to find another B with one.

They were an interesting answer to a problem that went away, much more unique than low flow cooling, for the same problem. 

[other dog]

On 3/28/2026 at 11:52 AM, mowerman said:

always nice to ask questions constantly about oils,,,, i will be doing the same thing soon with a triplex,,,,i would have just put 90 weight in it,,,bob

Remember back when all this was simple?..you put 90 wt. in the transmission, 140wt. in the rear ends.

[other dog]

On 3/27/2026 at 8:36 PM, Geoff Weeks said:

Let be start by saying I have zero experience  with the newer RTLO series.

All the roadrangers I worked on were the older RT-RTO series. I haven't been inside one in almost 10 years now 😮.  I remember there being a reason the old series can't take a 13 and make it an 18 with just a knob change. 

 So I am going to disappoint just about everyone including myself and say I don't remember why.

There is no reason not to use highside low on a 9 spd or a 13 (or 18) where it becomes more risky is when you use the splitter gear. You are multiplying the input torque through the the front box, then passing though the splitter gearing, and it isn't designed for that. In direct the power flows straight through the back box.

 The reason it is not generally used in a 9 spd or others is it is a ratio in between 4th and 5th (or 3rd and 4th if you use the "low" terminology) and the step between that isn't a even step.  

 If you're climbing a grade it may be tempting to use "funny gear" as it used to be called (highside low) but the jump down is a bigger one then it is to low side high, and it means any further downshift will also be another un-even drop. The low range gears are larger and better able to take the torque input for long periods than high side low.

 Empty I also have used funny gear many times, 1-2-3 (or if you must, lo-1-2) flip to high and go back to 1st, it is a bigger jump than continuing on in low and the jump from there to the next gear up is  bigger jump than shifting as you "should". I only did it empty, not saying it is better or great but no harm will come. 

sorry not to remember better, a mind is a terrible thing to loose!

We used to call it "cheater gear". I heard that it was the same ratio as 5th. gear on the low side, or nearly the same, so there was no real advantage to using it. Of course I had to try it a few times just to see. 🤣 

[Geoff Weeks]

Not old enough to ever been around worm drives and 140, Hypoid or Amboid with 80w-90 for me.

[Geoff Weeks]

1 minute ago, other dog said:

We used to call it "cheater gear". I heard that it was the same ratio as 5th. gear on the low side, or nearly the same, so there was no real advantage to using it. Of course I had to try it a few times just to see. 🤣 

It is in between  4th and 5th. not exactly in the middle of those two.

[other dog]

On 3/27/2026 at 10:39 AM, Freightrain said:

I couldn't take the green paint on the transmission so it is now black.

Much better!

  😆 

Darn...I was liking the green.

[other dog]

On 3/28/2026 at 11:58 AM, Freightrain said:

I asked the shop I got this from and he explained it to me why not to make a phony 18 spd.  I could have had him do the bearing upgrade for me then but I don't have any real reason to need splits on the low side.

You are absolutely correct. And tjc transport is absolutely correct, you will love the 13 speed. 

I drove several trucks with 18 speeds, and they are fantastic transmissions, I loved them. But very seldom did I ever split the gears in the low side. A couple of times splitting the last 2 came in handy, but 99% of the time I drove it like a 13 speed.

[Mark T]

1 hour ago, other dog said:

You are absolutely correct. And tjc transport is absolutely correct, you will love the 13 speed. 

I drove several trucks with 18 speeds, and they are fantastic transmissions, I loved them. But very seldom did I ever split the gears in the low side. A couple of times splitting the last 2 came in handy, but 99% of the time I drove it like a 13 speed.

That's been my experience with them too. That's on a fairly up hill chug too. They do go a little further down in reverse and low though which is nice for dump stuff. Trailer or truck.