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Discussion Starter · #1 ·
Are there physical differences in the transmission core itself between the Eaton 18-speed manuals and the equivalent auto-shift (3-pedal)? Have any of you converted an auto-shift to manual (or vice versa)? I've not read anything definitive on this, but one person claimed there are some internal differences in mechanical tolerances with regards to the shifters. Somehow the manual has tighter tolerances in the shift mechanism, whereas the autoshift has looser tolerances. And of course there can be a difference in the ratio of the Low gear.
 

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Yes there are several differences, what are you trying to do? It is not possible to take the XY shifter off a Autoshift and put a stick on it. You physically need to replace the transmission for it to work. The Autoshift is a A ratio transmission versus the manual being a B ratio. The case is not the same so it needs to be replaced as none of the machining for the slave valve is done for it. The aux section case would need to be replaced as well. There is physical differences internally as well. The automated unit has wider spacing on the sliding clutch teeth, newer models will have a flame sprayed shift fork in the automated as well to increase life out of the automated.

If you want more information PM me and we can have a discussion there.
 

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Discussion Starter · #3 ·
I'm not trying to do anything at present. Just curious as I read in several places about people wanting to convert autoshift to full manual and who claimed they had a shop who could do it.

If anything I'd want to put autoshift on a truck. I just haul grain a bit on flat roads and not at tremendous speeds so I could do without having to shift, honestly. Probably the opposite of most folks I guess.
 

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Honestly with the extended warranties it is cheaper to swap in a reman unit versus trying to convert, I also forget to mention you will need a new shift bar housing and a couple of bearings as well. It is really financially unrealistic to go from a manual to a automated transmission as the complete truck would be required to rewired.

I am with you could not pay me enough to shift again. There are enough good products out there (Eaton UltraShift Plus, Volvo I-Shift, Mack M-drive and Don's favourite Allison) know that do not require you to shift, why would you.
 

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The reason we shift is because that is what we can afford to buy or all that is available in the price range that we are wanting to spend on a truck. I would think a 18 speed manual is a little simpler transmission than a 18 speed automatic.
 

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Speaking of getting out of the truck to shift, I hopped in the neighbors old Kenworth to move it in his yard, I guess I couldn't contort myself as well as I used to because I've driven it before. You know that saying about opening the door to let the clutch out, yeah ... I had to do that so my knee had someplace to go :D. Thankfully I doubt most trucks on the road are as cramped with the dash/steering column as the old Kenworths were.

I've never had the opportunity to drive an automated transmission, I might like it too much if I did and then know what I'm missing. I like the manual 18 speed though for being able to skip splitting lower gears when I don't need to and yet are there when conditions or load warrant.
 

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Discussion Starter · #9 ·
Yeah I'm fine with the 18-speed. It's almost fun. I'm not so good at it though. I think the problem is that I'm used to driving an older truck with a stiff, manual throttle pedal, so I'm used to the engine taking 3 seconds to fall from high RPM to low RPM. With the S60 in the semi, it's about half a second and it's at 700 RPM. Simply being faster to shift is helping. By the time I've pulled it out of gear, it's just about right to put in the next gear straight away.

I'm also not so good at driving for better fuel economy. I guess a super b with 500 HP isn't going to be that efficient anyway. Just seems like I'm always working it hard. Takes me a long time to get up to highway speed too.

I agree with Northern Farmer. The 18-speed gives you options. I mostly drive it like a 13-speed, but in and around the field, I use the lower splits a lot.

Allison has their new 10-speed full automatic (not auto shifting) that's rated for 600 HP, 1700 ft-lbs torque. That in theory could pull a super b, but it's not certified by Allison for loads that high. I've read reviews that are pretty glowing. Constant acceleration makes things very smooth and way better on fuel. A locking torque converter removes a lot of the inefficiencies there. And with the jake brake on you get constant engine braking all the way down. No abrupt removing of torque between gears while speeding up or slowing down. Maybe some day they'll release one that can handle a super b. They are twice the cost of an eaton manual transmission, and not available except in brand new navistar trucks thus far. With fuel efficiency regs coming down the pipe, it's possible that manuals (full manuals anyway). I'm sure there will be gnashing of teeth, but in another generation, no one will care. Kind of like how we all love our CVTs on tractors now.
 

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Speaking of getting out of the truck to shift, I hopped in the neighbors old Kenworth to move it in his yard, I guess I couldn't contort myself as well as I used to because I've driven it before. You know that saying about opening the door to let the clutch out, yeah ... I had to do that so my knee had someplace to go :D. Thankfully I doubt most trucks on the road are as cramped with the dash/steering column as the old Kenworths were.

I've never had the opportunity to drive an automated transmission, I might like it too much if I did and then know what I'm missing. I like the manual 18 speed though for being able to skip splitting lower gears when I don't need to and yet are there when conditions or load warrant.
I got a chuckle at your visual of opening the door on the KW to let the clutch out! I am 6'6" so been there, done that!

I also like my 18's for the ability to grab the next gear in low speed soft field situations. Way better than 13's. I have never even driven an auto shift but have heard that they do not shift well in those field conditions. Any truth to that rumor?
 

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I also like my 18's for the ability to grab the next gear in low speed soft field situations. Way better than 13's. I have never even driven an auto shift but have heard that they do not shift well in those field conditions. Any truth to that rumor?
I have both. A regular 18 in my 03 Mack and the 18 autoshift in the 07 Pete. Like any transmission it takes awhile to get used to how "you" want to drive the autoshift, full auto, part auto/part manual or full manual all the time. Transmission don't care and also won't allow you to do things that may hurt it. In the soft field I prefer the autoshift, fast clean shifts. I run mine in manual mode in the field and soft roads, still like to have that little bit of control. If I was buying a new truck it would be a no brainer, autoshift all the way!
 

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I have both. A regular 18 in my 03 Mack and the 18 autoshift in the 07 Pete. Like any transmission it takes awhile to get used to how "you" want to drive the autoshift, full auto, part auto/part manual or full manual all the time. Transmission don't care and also won't allow you to do things that may hurt it. In the soft field I prefer the autoshift, fast clean shifts. I run mine in manual mode in the field and soft roads, still like to have that little bit of control. If I was buying a new truck it would be a no brainer, autoshift all the way!
If you like the auto shift, wait until you get a chance to drive the UltraShift Plus, it puts the auto shift to shame for speed of shifting.

It will be interesting to see if the Allison 10 speed gets any traction in the market, especially if it is only rated to 1700 ft lbs, which means you would be only able to get a 1650ft/lb engine, and I do not know many engine companies make 600 hp 1650 ft/lb engines.
 

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It will be interesting to see if the Allison 10 speed gets any traction in the market, especially if it is only rated to 1700 ft lbs, which means you would be only able to get a 1650ft/lb engine, and I do not know many engine companies make 600 hp 1650 ft/lb engines.
Electronics have to handle that one.
It's been an unbelievably slow release of the TC 10, I think they unveiled it almost 4 years ago.
 

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I would think that the automated transmission has certainly put a crimp into the potential sales Allison could have had with some truck setups and for buses, assuming buses are or at least could use the automated trans ?. In saying that, I still think that it would be hard to beat an Allison for use in stop and go use such as garbage trucks, city transit buses or anything where one wants to do a lot of slow inching or starting out softly or to get under way in soft conditions. Drop boxes to power pumps and having that torque converter.

Another nice feature about the Allison is the ability to have the hydraulic retarder, works so smooth and its totally quiet so it can be used in cities. Not to mention for us tall guys that have issues of where our knee goes when letting out the clutch, gets cold in the winter if one has to open the door often :D
 

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In my opinion the auto shift and unltrashift want to shift to much in the soft or questionable field situations. Then there is the other problem of them wanting to start off in second gear all the time even if the load would require you to start in first gear. So with that being said I will stick to the manual shift trans at least for the foreseeable future anyway.
 

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In my opinion the auto shift and unltrashift want to shift to much in the soft or questionable field situations.

That is why I use mine in manual mode in the field and in soft conditions.

Then there is the other problem of them wanting to start off in second gear all the time even if the load would require you to start in first gear.

Not sure what you have but my shifter has, from the bottom up;
(1) low - starts in first gear every time and stays there. Have to move shifter to manual or auto mode to shift out of 1st.
(2) Manual - Mine is programed to start in 3rd and then just touch button on side of shifter to shift up or down. The transmission will also remember which gear you started out in last time if you selected a gear different than 3rd and will start in that gear unless overridden.
(3) Auto - Also programed to start in 3rd, just let transmission shift for you.
Also Neutral and then Reverse which is self explanatory.
Transmission can be programed to start in any gear you want, within reason, it won't let you start out in to high a gear, it is smarter than us.

So with that being said I will stick to the manual shift trans at least for the foreseeable future anyway.
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