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Need help selecting transmission for new Granite


leegsr52
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I'm trying to decide on transmission for a new Granite. Have narrowed the choices, with the help of my Mack dealer, to the T318LR 18 speed or the T310MLR 10 speed.

Let me start off by saying that I am a big fan of the old 12 speed. For construction and off road, I think it is the best transmission that Mack ever made. Just my opinion.

That being said, and never having driven either of the two newer transmissions, I'm trying to get as close as I can to the old 12 speed as far as reverse gearing, and close ratio shifting.

The thing I like about the 10 speed is the five shiftable reverse gears, similar to the old 12 speed. It also has very low crawler gears. The thing that bothers me about it, is the wide spread in ratio between forward gears. No splitting available in the forward gears. I've heard complaints about this this style of transmission, when it comes to pulling hills, and not being able to grab a half a gear.

The thing I like about the 18 speed is having the ability to split gears. The thing it lacks is the the shiftable reverse gears, and low speed ratios aren't as low as the 10 speed.

Looking for your opinions or experiences on either of these transmissions. There is also the allison auto transmission option. But I'm not sure if that would be a good option.

Edited by Lee G
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I suggest you consider an AMT. It will reduce your fuel bill, maximize performance and increase the truck's resale value. In your case speaking of a Granite, I'm talking about the dedicated vocational range of UltraShift Plus AMT trannies. The 10, 11 and 13 speeds have 3 reverse gears. The 18-speed has 4 reverse gears (with AMT, you don't need quite as many gears).

And unlike the single countershaft Volvo i-shift (rebadged as Mack M-Drive), the UltraShift Plus AMTs have Eaton's time proven twin-countershaft architecture.

http://www.eaton.com/ecm/groups/public/@pub/@eaton/@roadranger/documents/content/ct_243345.pdf

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For a new dump truck I would vote for the Allison as above, but of your pics I would vote the 18spd. If you were open to suggestion, the 310MLR is geared too low, I would guess your going to gear your truck around 4.42-4.64 if so you'll never use the low gear,ever. My 04 Granite had the 310M with 4.64 rears on 11R24.5's and it was just right, I rarely used the lowest gear in it even when hauling shot rock off road the MLR version is just too low unless your going with a 4.17-3.86 gear. I like the 310 it is as close to the old 12 speed as you will get the 18 just isn't the same and I've had all three. As for automated manual transmissions they just don't give the smooth slow takeoffs and stops needed for job site work off road or paving and milling. The Allison is the best choice for any vocational truck but if your set on a manual you can't go wrong with a T310M and 4.64-4.42 rears on tall 24 rubber or 4.42-4.17 on tall 22 rubber. If your going to go higher in the gearing to get your rpm down on the road you could use the gears in the T310MLR but I wouldn't get it without something like 4.17-3.89 on tall 24's or 3.89-3.86 on 22's. That 20 something to 1 low is just crazy low, 8LL Eaton's are 14.56-1 LL gear.

"Any Society that would give up a little LIBERTY to gain a little SECURITY will Deserve Neither and LOSE BOTH" -Benjamin Franklin

"If your gonna be STUPID, you gotta be TOUGH"

"You cant always get what you want, but if you try sometimes you get what you need"

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OK I couldn't remember the gear ratios so I went and got my books out,

the low / high gear ratios are....

TRTXL 107- 18.56 - 1.00

TRTXL-1070- 14.44 - .78

T318- 13.44 - .71

T318LR- 16.42 - .71

T310M- 17.35 - .73

T310MLR- 27.30 - .71

eaton 8LL- 14.56 - .74

There we go from that you should be able to see what a difference your looking at in low gear ratios, I just cant see the 310MLR for anything with rears lower than a 3.86 for my uses its just crazy low the one I drove you could put it in low let off the clutch and probably get out, walk around the truck and get back in and it would have gone about 5 feet, it had 4.64 rears on 11R22.5 tires. The 310 MSR transmissions have 6 reverse gears and the 310M I had worked great for paving and road work where I had to back up from one crossover to the paver maybe a 1/4 mile, it shifts in reverse just like in forward. The gear steps in the T310MLR are actually the farthest apart of any of the transmissions I listed because of the extreme low and .71 OD and it will be a big step in high range, the 310M on the other hand is a close ratio transmission and I loved it compared to an 8LL in high range. The 318 series is going to be the closest gear step of all the 318LR is right with it with the low gear for vocational work but it is a splitter transmission not multi speed so you can split from under to high in low or high range in reverse but not between the high and low range while moving. I would opt for an Allison like Reel Addiction said before it is probably the best option you can get for a vocational truck and with the added torque multiplication of the torque converter it will pull just as good as the 10 speed trucks and pass them doing it since you don't have to shift, I think the norm is a 5.02 rear ratio with a 4500 series 6 speed Allison the top gears are in the .67 area it would be the way I would buy a new vocational truck. Hope that helps, the dealers really try to push the 310 MLR now but its just too low for most people to use and the gear steps are way off in high.

Heres a link to an Allison video that proves (using Mack trucks) what they can do.

http://www.youtube.com/watch?v=UvWPRpF_CTg

"Any Society that would give up a little LIBERTY to gain a little SECURITY will Deserve Neither and LOSE BOTH" -Benjamin Franklin

"If your gonna be STUPID, you gotta be TOUGH"

"You cant always get what you want, but if you try sometimes you get what you need"

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Go 18spd for sure if not a Allison. I have owned both and the 18 is by far better choice. You have a forward gear for every condition u encounter and still have 4 reverses. My trucks do a lot of backing up and besides from the old 2 sticks the 18 is the best. Make sure its the low reverse though. I have one that isn't and the high range reverses are useless. That 10spd will make the same motor feel like 100hp less when upshifting

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If you want to increase your profits and reduce operational costs (keep more money in your pocket), you really should consider AMT.

The latest generation Eaton AMTs are impressive. And only Eaton offers an AMT range specifically tailored for the construction segment.

Penske, a shrewd businessman never shy to complain, runs thousands of Eaton AMTs. And, Eaton AMTs have been THE transmission of choice in the demanding Australia/New Zealand and South Africa markets for years.

Compared to the Allison, the UltraShift PLUS AMT is a much easier installation with better chassis integration, has a lower maintenance cost, better fuel economy and good shift quality (equal to the Mercedes-Benz “PowerShift 2” and Volvo “i-shift” AMTs).

Allison has its place in the stop-and-go segments (refuse trucks and municipal transit buses), but in vocational construction, regional and long haul, AMT is generally now the way to go (because of the fuel economy benefits).

You’re going to be seeing the impressive Mercedes-Benz “PowerShift 2” AMTs more and more (rebadged as the Detroit DT12 AMT in Freightliners).

Allison’s new TC10 twin-countershaft hybrid is very heavy, costly and somewhat less efficient than Eaton’s UltraShift PLUS AMTs.

To get good braking from an engine brake, you need to keep the engine speed up. This is why Allison talks about early downshifts with an engine brake because that’s how they keep the engine revs high. If you compare an Allison 4000 with the current generation of 10-speed Eaton UltraShift PLUS AMTs paired to a Cummins ISX, the performance will be similar at higher road speeds. But at low road speeds, the limited ratios of the Allison make it harder to get high engine speeds in braking. With the torque converter in lockup, you only have a few gear ratios in the transmission to get the highest engine speed during braking (e.g. 3.51, 1.91 and 1.43). Gear ratios in the UltraShift PLUS AMT allow for faster engine speeds at lower driveline speeds using similar axle ratios. Also, with similar axle ratios, the startability with the UltraShift PLUS AMT is almost two times better than the Allison. In summary, high speed braking is similar, but low speed braking favors the Eaton AMT.

Eaton UltraShift PLUS AMTs are more fuel efficient and reduce heat load on the truck’s cooling system.

The Allison’s purchase costs, operating inefficiency and service requirements are its detriments (in applications like mining, those higher costs are not an issue).

One of the challenges with Allison's torque converter-type automatic transmission is when the torque converter is active, there is a lot of slipping and heat generation. When the torque converter locks up, the slipping ends and heat generation is largely gone. If the truck application requires a lot of slow speed driving, the Allison automatics can get hot. However the Eaton AMT in the same application has no such heat problem because UltraShift PLUS AMTs don’t use a torque converter.

If you could order a Mack T300 AMT, you’d have the best of all worlds. At the time Volvo acquired Mack Trucks, Mack was designing an AMT version of the Mack T300 transmission. But Volvo shunned Mack engineering and terminated that project, favoring their single-countershaft i-shift over the superior triple-countershaft Maxitorque transmission. Volvo wanted to use their weaker single countershaft design (even ZF, like Eaton, uses a double countershaft design for their AMTs).

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When I worked for Mack the shop did a few of those changeovers that guys ordered 13's then wanted it changed to an 18 and I remember the mechanic doing something else underneath by the trans I just don't remember what he was doing but said this was the right way to do it than just changing the knob. This was 97 so my memory is a little foggy.

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I have nt ever looked into a Mack trans but an Eaton has different gears and bearings in the low range gears from a 13 to an 1, I had heard Mack was all the same but like I said I got no confirmation on that one.

"Any Society that would give up a little LIBERTY to gain a little SECURITY will Deserve Neither and LOSE BOTH" -Benjamin Franklin

"If your gonna be STUPID, you gotta be TOUGH"

"You cant always get what you want, but if you try sometimes you get what you need"

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If you want to increase your profits and reduce operational costs (keep more money in your pocket), you really should consider AMT.

The latest generation Eaton AMTs are impressive. And only Eaton offers an AMT range specifically tailored for the construction segment.

Penske, a shrewd businessman never shy to complain, runs thousands of Eaton AMTs. And, Eaton AMTs have been THE transmission of choice in the demanding Australia/New Zealand and South Africa markets for years.

Compared to the Allison, the UltraShift PLUS AMT is a much easier installation with better chassis integration, has a lower maintenance cost, better fuel economy and good shift quality (equal to the Mercedes-Benz “PowerShift 2” and Volvo “i-shift” AMTs).

Allison has its place in the stop-and-go segments (refuse trucks and municipal transit buses), but in vocational construction, regional and long haul, AMT is generally now the way to go (because of the fuel economy benefits).

You’re going to be seeing the impressive Mercedes-Benz “PowerShift 2” AMTs more and more (rebadged as the Detroit DT12 AMT in Freightliners).

Allison’s new TC10 twin-countershaft hybrid is very heavy, costly and somewhat less efficient than Eaton’s UltraShift PLUS AMTs.

To get good braking from an engine brake, you need to keep the engine speed up. This is why Allison talks about early downshifts with an engine brake because that’s how they keep the engine revs high. If you compare an Allison 4000 with the current generation of 10-speed Eaton UltraShift PLUS AMTs paired to a Cummins ISX, the performance will be similar at higher road speeds. But at low road speeds, the limited ratios of the Allison make it harder to get high engine speeds in braking. With the torque converter in lockup, you only have a few gear ratios in the transmission to get the highest engine speed during braking (e.g. 3.51, 1.91 and 1.43). Gear ratios in the UltraShift PLUS AMT allow for faster engine speeds at lower driveline speeds using similar axle ratios. Also, with similar axle ratios, the startability with the UltraShift PLUS AMT is almost two times better than the Allison. In summary, high speed braking is similar, but low speed braking favors the Eaton AMT.

Eaton UltraShift PLUS AMTs are more fuel efficient and reduce heat load on the truck’s cooling system.

The Allison’s purchase costs, operating inefficiency and service requirements are its detriments (in applications like mining, those higher costs are not an issue).

One of the challenges with Allison's torque converter-type automatic transmission is when the torque converter is active, there is a lot of slipping and heat generation. When the torque converter locks up, the slipping ends and heat generation is largely gone. If the truck application requires a lot of slow speed driving, the Allison automatics can get hot. However the Eaton AMT in the same application has no such heat problem because UltraShift PLUS AMTs don’t use a torque converter.

If you could order a Mack T300 AMT, you’d have the best of all worlds. At the time Volvo acquired Mack Trucks, Mack was designing an AMT version of the Mack T300 transmission. But Volvo shunned Mack engineering and terminated that project, favoring their single-countershaft i-shift over the superior triple-countershaft Maxitorque transmission. Volvo wanted to use their weaker single countershaft design (even ZF, like Eaton, uses a double countershaft design for their AMTs).

This is great information but its clear you have never driven either in actual use, I can tell you that there is no slipping an AMT to get very slow speed operation needed during paving and milling operations, the clutch is engaged and out and engaged and out and it is not smooth enough to stay in front of a milling machine unless you spec it with gears low enough to get the clutch fully engaged by 1 mph and keep it there, then you have no top end. The Allison has no clutch and therefore can be used from 0-top end speed very smoothly and there is also no clutch change needed every couple years as with every AMT I have ever heard of. The Allison keeps smooth power on the drive tires off road in rough terrain and loose materials where the AMT or Manual transmission ends up with driveline slack and shock loads. I agree AMT transmissions are the future for on road applications but Vocational trucks are just not suited to them and so far everyone I have heard of trying one hated it in slow speed operation, that same slow speed operation is where the Allison shines and I have never seen one get hot during slow speed operation, probably because you are not using enough throttle to heat it up. Just my two cents, Ive driven Dumps, Medium Duty trucks, School Buses, Coach Buses and Fire trucks with Allison transmissions and never had an issue. I would say that a School bus is a heavy service Application, Allison rates School Bus use as Heavy in their paperwork and when running 84 and 90 passenger Blue Bird's with 8.3 Cummins 260-315hp engines grossing around 35,000# loaded, running two routes morning and afternoon averaging 150 stops a day, plus red lights and school zones and never having an issue they do pretty well. The only maintenance we ever did to out MT643's was change the external spin on filter every 5,000miles during each service and change the internal filter and all the fluid once a year, same with the 3000 series actually just having two internal filters. OK Im done I rate the Allison A+ and the AMT transmissions about an A- and that's over the Mack manuals being a B and the Eatons a C and spicers a , maybe an F for longevity in my relatively short experience.

"Any Society that would give up a little LIBERTY to gain a little SECURITY will Deserve Neither and LOSE BOTH" -Benjamin Franklin

"If your gonna be STUPID, you gotta be TOUGH"

"You cant always get what you want, but if you try sometimes you get what you need"

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  • 3 weeks later...

Thanks guys! Talk about confusing the issue! LOL

So, here's what the specs are so far:

20,000# front axle - 425x22.5 rubber (needed to get the 20k rating, unless I go with the 315/80R22's, but they don't fill the wheel wells)

20,000# steerable pusher - 425x22.5 rubber

46,000# Mack double locker rears - 12R24.5 rubber

Axle ratio - 4.10

Single deep frame (just made it under the single frame length limit with a 153"ca and 241" wheelbase

MP8 - 415HP (maybe 425)

T310MLR transmission or T318LR (hence...the undecided issue!) These two currently being the options I think would be best for our situation (Then again, the last time a specd. a new truck, was in 1987 - with a twelve speed, which by the way, I think Mack should still be making. Thank you emissions!

That is one reason why I was thinking about going with the T318LR, because you CAN split forward gears. The only issue I have with the transmission, correct me if I'm wrong, is that you can't shift through reverse gears (well...the first two), like the T310MLR. Near as I can find out through Mack specs, the T318LR has a low reverse ratio of 29.98, then 24.58 and 6.41(can you say....useless!?), in comparison to the T310MLR with a low of 23.96 through 2.40, which you can actually shift through. Too bad they couldn't figure out a way to do that with the 18 speed....what a combo that would be!

I recently spoke with a contractor friend of mine, who bought an RD 10 wheel dump with the Allison. He's not thrilled with it. He says you don't retain control enough over the truck when backing down steep slopes and such.

The application we're using this truck for is as a volumetric (mix-on-site) concrete mixer. http://www.zimmermanindustries.com/en/index.php?option=com_content&view=category&layout=blog&id=5&Itemid=19 Although in a majority of our work, our truck stays on the pavement, we do go onto job sites and residential sites, where we really need a low creeper gear. I've had jobs where we've had to back up 45 degree inclined driveways starting from a dead stop at the road, loaded to my max, which sometimes can end up being 80,000#+ (shhh...did I say that?) Also, we do a considerable amount of curb backing work, which requires a very low creeper gear.

Call me stubborn, but even though I'm pretty progressive when it comes to keeping up with with change and new technology, etc, I'm still a little old fashion, in that I would prefer my Mack to be ALL Mack. (well....as much as it can be these days....lol).

I'm beginning to think I should have just closed my eyes, and picked something off the lot!!

So, with all that being said, please, pick my opinions apart!

Thanks guys!

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I would go with a steeper rear axle, 4.10 isn't going to do as well off road and for the uses you just explained. I'd go with a 4.42 rear, especially with the tall rubber you'll still have plenty of speed on the road. All the dump trucks I've had and fun have been either 4.42 or 4.64 rears and all would run 70-75 just fine and have rpm left to give.

"Any Society that would give up a little LIBERTY to gain a little SECURITY will Deserve Neither and LOSE BOTH" -Benjamin Franklin

"If your gonna be STUPID, you gotta be TOUGH"

"You cant always get what you want, but if you try sometimes you get what you need"

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The math shows 1600rpm@70 with a 4.17 and 1700rpm@ 70 with a 4.42 but the overall gearing gains down low are pretty good.

"Any Society that would give up a little LIBERTY to gain a little SECURITY will Deserve Neither and LOSE BOTH" -Benjamin Franklin

"If your gonna be STUPID, you gotta be TOUGH"

"You cant always get what you want, but if you try sometimes you get what you need"

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So. I did some looking into the Allisons. The 4700RDS seven speed, with low range reverse and retarder looks like the top option for rugged duty application, If I were to go with the Allison. The lower first gear and second low reverse gear seems like it would give you better control in off road and/or slope conditions. Anyone's thoughts?

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the 4500 series is lighter and is plenty, you have to remember the torque converter, you gear it right and you wont need the 7 speed or the two reverse gears, they drive like a pickup truck with an auto give it more throttle it goes.

"Any Society that would give up a little LIBERTY to gain a little SECURITY will Deserve Neither and LOSE BOTH" -Benjamin Franklin

"If your gonna be STUPID, you gotta be TOUGH"

"You cant always get what you want, but if you try sometimes you get what you need"

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