Kenworth with 10 speed and a Detroit

I recently worked on a tandem dump truck that was built from a converted T600 tractor. It was a crap setup IMO. Those highway trucks don't have enough ground clearance for offroad use. The fairings are always dragging. This one also had a super 10. And the air bag suspension is pretty sketchy in a dump truck.

Anyway, the one I worked on would not engage the PTO. Once I tunneled my way under the low fairings I found that all of the air lines had been ripped off the PTO and valve. They were hanging way too low and snagged a root or dirt clump or something.

Super 10A --- Super 10B
1st 10.2 --- 1st 11.06
2nd 7.56--- 2nd 8.20
3rd 5.63--- 3rd 6.06
4th 4.25--- 4th 4.49
10th 0.75--- 10th 0.74

Standard shift pattern RTO 16210C
1st 12.69
2nd 9.29
3rd 6.75
4th 4.90
10th 0.73

The 10C is the best gear ratio for a dump. It has the 1st gear ratio of low in a 13spd and 10th gear ratio of top gear in a 13spd. 400 rpm drop each shift in the higher gears which is ok.

Thanks for the ratios. The client has a B model coming from the Kenworth dealer. Cost is right at $3,000 with $300 core charge. Parts guy said they don't really care if they get the core or not. The Peterbilt guy was about $30 less on an A model, 5 days away with freight cost plus $2,000 for the core. A road guy the lives close by is doing the R&R this weekend. Thanks for all the tips and help. I'll let you all know how this works out.

I find it interesting how different countries have different preferences as far as transmissions in trucks doing effectively the same job. The standard transmision for an Australian semi would be an 18 speed hands down. Thirteen speeds (RT 613) died out with International Accos and Ford Loosely builts powered by either petrol v8's, Cummins VT190's or 3208 Cats. Fifteen speeds (RT915 and up) were the heavy spec weapon of choice once, however the adventof the 18 speed rapidly lead to their demise as a common box. 10 speeds (RT610) were only common in lighter specced Acco's in my recollection. Of course, Mack went their own way to a degree with their 12 speed, although most Macks in recent years have had Roadrangers fitted. A few 13 and 15 speeds found their way into Japanese trucks such as Isuzu and Mitsubishi and it was always a source of amusement to see a farmer trade in his old 5 +2 truck on a usually second hand Jap truck with a 13 or 15 and then watching them trying to come to terms with the constant mesh range change box. They usually found a gear, ANY gear and crawled to a place well out of sight to try and get the hang of it.
It's strange how two countries can have such different preferences for getting the same job done.

You also have to remember that our weight laws are quite different here. 90% of all tractor trailer rigs in the US will never gross more than 80,000 lbs (say 36,000 kg). I'd say at least 70% of all straight trucks in the US will never gross more than 54,000 lbs (say 25,000 kg).

In fact, many dry van rigs in the US will never even see 80,000 lbs. Since the maximum trailer length is 53' for the most part, many rigs will "cube out" or basically run out of room for cargo before hitting max weight.

The only time you see 18 speeds here is on heavy hauling rigs, rigs that run only in a geographic area that allows more weight, or as a vanity option. For example, Michigan allows basically twice the gross weight of most other states. So, you see what they call the "Michigan Special". It's usually a day cab tractor with at least 500 hp, heavy axles, larger brakes, a 13 or 18 speed trans, and often a double or even triple frame.

Strange in alberta most all trucks i have owned and seen in my field of work where all 18 spd. 46 rear 20 frt...my baby international has a 10 spd 330 hp. Weird shifting from 18 to 10 though darn granny hole gets me everytime

18's came out in early 90's but only became available when high torque transmissions were needed because of the higher torque engines. When torque ratings reached 1550
the transmissions changed to tapered bearings in the rear section, the early ball roller couldn't take the torque. Plus with the changes on bearings the direct/over drive splitter
gear was moved from the very back to the front of the rear section allowing for the option of splitting the low range gears also. But the torque ratings are the same for
both 13's and 18's and in a OTR being able to split the bottom four gears is pretty useless. But the manuals are going away anyhow-autos have taken over.

When the company I worked bought a new fleet of logging trucks and had them equipped with the autoshift 18 speeds, we all though that they were crazy. Most of the drivers were offended. At the start it was a fairly low acceptance rate. The learning curve was fairly steep on something that you thought would be simple. But they figured it out.

Now 4 years I would say that it is probably better than 90% of the drivers like them now.

I had a pretty good talk with a couple of the drivers that I consider to be the best, about what they thought of the autoshifts.

First off, we are logging. The trucks are only empty on the hiway. Loaded they stay on the logging roads so they are loaded right up. Steep terrain so lots of shifting involved.

They pretty much all said that they were 50/50 about the auto's but the auto's were starting to grow on them. They liked that at the end of the day the right arm was not worn out from scrambling eggs all day.

Lots of the guys leave them in manual and use the buttons to up and down shift.

Interesting note here. The guys that use in manual mode tended to have less issues with the aftertreatment system.

What do you guys think about Allisons? I have never used an AMT style transmission. My experience is all vocational, regular manual or Allison it seems. I don't know if anybody actually uses Allisons on 80,000 lb road trucks.

One of the great benefits of an Allison is full power shifting so you can gain speed out of a pit or steep hill or something where a manual, automated or not, could never synchronize the next gear.

wornout wrench said:

Interesting note here. The guys that use in manual mode tended to have less issues with the aftertreatment system.

Click to expand...

Interesting to note about that. In the old days Allisons all seemed pretty well tailored to the engine from the factory. Last 10+ years, they seem to come with a stupid low performance program that has the truck in 5th or 6th gear by 25 mph. (5th is direct, 6th is OD for those reading) Every new truck, the Allison rep had to come out and reprogram to some kind of "high performance vocational" where the transmission actually attempts to keep the truck engine in power range most of the time. We them really fine tune tune them, so that going up a hill floored, the transmission would make an accurate decision about whether it could pull the next gear, or stay in the current gear near high idle RPM. Once this is done they are quite nice to drive, really makes the day shorter.

Birken Vogt said:

What do you guys think about Allisons? I have never used an AMT style transmission. My experience is all vocational, regular manual or Allison it seems. I don't know if anybody actually uses Allisons on 80,000 lb road trucks.

One of the great benefits of an Allison is full power shifting so you can gain speed out of a pit or steep hill or something where a manual, automated or not, could never synchronize the next gear.



Interesting to note about that. In the old days Allisons all seemed pretty well tailored to the engine from the factory. Last 10+ years, they seem to come with a stupid low performance program that has the truck in 5th or 6th gear by 25 mph. (5th is direct, 6th is OD for those reading) Every new truck, the Allison rep had to come out and reprogram to some kind of "high performance vocational" where the transmission actually attempts to keep the truck engine in power range most of the time. We them really fine tune tune them, so that going up a hill floored, the transmission would make an accurate decision about whether it could pull the next gear, or stay in the current gear near high idle RPM. Once this is done they are quite nice to drive, really makes the day shorter.

Click to expand...

Birken, we ran Allison's for years and still do in our off hiway truck. So Hayes HDX, Pacific P16, Kenworth 850's and such. Allison 5960/6061's.
Great trans and worked really well with not much problem. But those were in the big trucks that they don't make anymore and were not able to run anywhere but on the private logging roads, not for hiway use.

I know later on in life they were trying to fully automate them into a true automatic but I didn't have any time on them.

I loved those old monsters. Honking great big load of wood on it, right to the mat and just touch the shifter and bang, next gear.

And lets not forget about the retarder for keeping the speed in check on hills. Going back and forth between retarder, jake and some brakes they managed to keep those monsters held back on some pretty darn steep hills.

The big companies up in my part of the world all decided that they should be hiway trucks years ago. Many reasons but I think most of them were all BS. Obsolete parts was one of the big ones.

The funny thing is, the big dogs got rid of the fat trucks because they were too costly, the little dogs managed to buy up a bunch and the little guys do alright with them. They can still find parts.

Strange, but that is a tale for a different place and time. To many open wounds still.

I was more asking about 3000/4000, or the old 600/700 series Allisons, for on highway use. I don't know how the off highway CLBT numbers cross over to the MT/HT or MD/HD numbers.

I too liked to shift with the buttons where applicable. Some die hard manual fans would say why don't you just drive a regular stick then. Well it is a lot easier and a lot more foolproof to push a button and have it shift than yank another gear.

I liked to say it this way. In a pickup it seems that an automatic costs more outright, uses more fuel, needs more maintenance. In a vocational truck it is the opposite, except the purchase price. They usually operate more efficiently unless there is a really good driver. They get the load to the destination sooner. They don't need clutches, shift forks, and the like. Less stuck-in-the-mud calls because it is easier to soft pedal your way out. That is for converter based transmissions. I have no experience with AMTs like I said earlier.

Most fire apparatus these days is Allison trans equipped, hold up to some pretty sever service when called upon, 90% of fire trucks cannot be scaled as are over axle weight from the get go. Last large pumper I got to run, tandem Kovatch (KFE) had 66,000 on the drives and 20,000 on the steer, 86,000 gross weight and just a straight Truck., 2800 gallons water, additional 500 gallons foam concentrate, hose lays, hard suction line and rescue tooling for highway accidents. The rest was all structure to hold it together. had a Cummins M11 in it on a Allison I have no clue as to.

Wes J said:

You also have to remember that our weight laws are quite different here. 90% of all tractor trailer rigs in the US will never gross more than 80,000 lbs (say 36,000 kg). I'd say at least 70% of all straight trucks in the US will never gross more than 54,000 lbs (say 25,000 kg).

In fact, many dry van rigs in the US will never even see 80,000 lbs. Since the maximum trailer length is 53' for the most part, many rigs will "cube out" or basically run out of room for cargo before hitting max weight.

The only time you see 18 speeds here is on heavy hauling rigs, rigs that run only in a geographic area that allows more weight, or as a vanity option. For example, Michigan allows basically twice the gross weight of most other states. So, you see what they call the "Michigan Special". It's usually a day cab tractor with at least 500 hp, heavy axles, larger brakes, a 13 or 18 speed trans, and often a double or even triple frame.

Click to expand...

And 9 to 14 axles.

wornout wrench said:

When the company I worked bought a new fleet of logging trucks and had them equipped with the autoshift 18 speeds, we all though that they were crazy. Most of the drivers were offended. At the start it was a fairly low acceptance rate. The learning curve was fairly steep on something that you thought would be simple. But they figured it out.

Now 4 years I would say that it is probably better than 90% of the drivers like them now.

I had a pretty good talk with a couple of the drivers that I consider to be the best, about what they thought of the autoshifts.

First off, we are logging. The trucks are only empty on the hiway. Loaded they stay on the logging roads so they are loaded right up. Steep terrain so lots of shifting involved.

They pretty much all said that they were 50/50 about the auto's but the auto's were starting to grow on them. They liked that at the end of the day the right arm was not worn out from scrambling eggs all day.

Lots of the guys leave them in manual and use the buttons to up and down shift.

Interesting note here. The guys that use in manual mode tended to have less issues with the aftertreatment system.

Click to expand...

The tandem axle heavy spec state and county snow plow trucks around here all have had autos for many years. The guys tell me that no matter if plowing snow or hauling gravel, after they self shifts to 3rd they hit the button and manual shift the upper gears except occasionally when running empty.

Birken Vogt said:

One of the great benefits of an Allison is full power shifting so you can gain speed out of a pit or steep hill

Click to expand...

I looked at a 130,000 lbs crane this weekend that was allison. And loaded up heavy like that, there's no power shifting uphill. You want to manually select 1. If it makes the shift to 2, it will immediately bog down, hammer shift right back up to full in 1, then back to dogging it in 2. Its a see saw mess.

I found heavy that I prefer a manual, they hold up better, and you're so much closer to being in the right spot in the powerband with 13 gears vs. 5 in a allison.

I think the only thing that holds back the Allison is the cost. I believe it's about a $20,000 option at the time of purchase. And the maintenance costs are also quite high. Oil is $40/gallon and needs to be changed every 25,000 miles or so.

That said, the Allison does prop up the resale value of a truck. Especially in a dump truck and Allison will add $5-10,000 to the used price.

Lots of information here! I breezed through it and hope I am not saying anything again.
I will share this: Fuller transmission sticks can come out of place due to the shift tower, as someone mentioned. They can allow the ball of the stick to get to far from the transmission. That can also cause the lever to lock up on the shift rail. Yes very rare.
The older models just had an o-ring in the top of the tower. The ball could wear into the housing and trash the housing. Later models had a steel washer under the o-ring. Those prevent the housing damage but when the o-ring is bad the stick can still get out of place. Just replace that and you will probably be good. Might want to do the isolater bushing, if it has one, while you are there.
It is not a good week when you weld on the stick, replace the transmission top, then the transmission and find out the the tower is bad. Driver does not speak English. He would jerk around with it and get it back home. We were catching it form the office. Could not understand him or find anything wrong to start with.

crane operator said:

I looked at a 130,000 lbs crane this weekend that was allison. And loaded up heavy like that, there's no power shifting uphill. You want to manually select 1. If it makes the shift to 2, it will immediately bog down, hammer shift right back up to full in 1, then back to dogging it in 2. Its a see saw mess.

I found heavy that I prefer a manual, they hold up better, and you're so much closer to being in the right spot in the powerband with 13 gears vs. 5 in a allison.

Click to expand...

The first part is true, 1-2 shift might have to be locked out, that is why they have a shift selector that goes all the way to 1. If they are programmed correctly as I mentioned above they will not attempt a 3-4, 4-5 or 5-6 shift unless they know the engine will pull it. But in the low gears that kind of programming is too finicky, the driver still has to somewhat have a brain.

As to whether they hold up better, in my old vocation, propane, there was a lot more work done to driver abused Roadrangers than to Allisons.

Wes J said:

I think the only thing that holds back the Allison is the cost. I believe it's about a $20,000 option at the time of purchase. And the maintenance costs are also quite high. Oil is $40/gallon and needs to be changed every 25,000 miles or so.

That said, the Allison does prop up the resale value of a truck. Especially in a dump truck and Allison will add $5-10,000 to the used price.

Click to expand...

Their little maintenance calculator says 300,000 miles in vocational service with some made up numbers I gave it, if you are using TES-295 synthetic, which they all come with for 10 years or more.

FWIW, I used to work in a foundry that made some parts for Allison Transmissions. Talk about a bunch of first rate A-holes. My boss threw one of their quality control reps out of our building followed by a "never come back".

I'll never buy an Allison product if I can help it.

Have been in a few machines with Allisons, not been disappointed by service life or dependability.