Go back and check my orig. post. I said "pro Classes." I know you see autos all the time in lower classes, I even ran and auto in super street. It, however, was not low stall, it was very high stall, like 5500 rpm.

 

I am well aware that they are not otr trucks, I am also aware of the fact that where I live, that is how 90% of them get used. They pull goose neck trailers over the road. They are all over loaded, and the manual tranny outpulls the auto. The few people i know who bought autos tore them up in short fashion. I on the other hand, dont try to use a F350 and a goose neck for a 10 wheeler, I just use a 10 wheeler or an 18 wheeler. I stand behind what I have seen, the auto does not pull as well or last nearly as long in this type enviornment. It also does not fare as well on fuel. If the auto is as efficient as You contend, The allison would hold much more market share in the 10 wheeler industry. I would guess it is less than 2% of the market. Much scarcer than that in larger tractors. I work my work trucks. The maximum trailer weight is determined by how much I can haul without scrubbing the tires. I have not had very good luck with automatic transmissions.

 

PEOPLE, MANUALS ARE BETTER FOR TOWING!!!!!!!!!!!!!!

 

What he said.

Now if you want to race with a load. I recommend the auto. Myself. I dont race with a load but im very confident with my manliness.

I dont need a 3 foot lift and 44 inch tires to try to convert my truck into some kind of phalic symbol. If I wanted to overcompensate. I would get a vette or a viper.

The torqueshift has 6 gears choices but will only use 5 at a time. It uses a different gear for cold weather but will never shift 6 times.

 

I agree, but at all levels? I agree, manuals are better for towing than autos in super heavy loads like OTR trucks use, but I think that the Allison and the Torqushift are very strong trannies. With as many autos that are being sold today in this market, I don't foresee a lot of dead trucks due to their transmissions.

 

Auto transmissions used at near gross do not last very long in these light duty trucks. I have read that an auto failing between 30k and 100k would be considered normal. At the highest weight rating.

How are the hotshotters doing with the allison?

 

Allison already has a tranny that makes multiple ratio combinations. The reason its not popular is due to fuel economy loss.

 

Oops. I'm sorry. I thought this was the PSD/TS vs. Cummins/5600 thread. Let me caveat my statements. A PSD/TS is better for towing than a Cummins/Manual. The PSD will haul more, go faster, accelerate better, and start the tow easier. The goal of the PSD/TS design team was to achieve that ... and they did. Congratulations to them. Purchasing a manual transmission for the PSD is not necessary, and would take a very special set of conditions to justify it.

Purchasing a Dodge Cummins/Manual is also not necessary, really, for anything that I can think of, other than if you prefer the look of Dodge trucks, or perhaps your cousin runs the dealership and is giving you a super financial deal, or maybe you're just wanting to pretend you have that 18-wheeler job you always wanted but never pursued, so you want the look and feel of driving a low rpm truck with manual gears. Hey, that's a valid reason. Why not? My buddy drives a 1968 Bentley ... not because it's the best performing luxury sedan someone could buy ... not because it's full of the latest technology. It has a nice tea tray that pulls out in the front seat. You can grease your front end from the driver's seat with the push of a button.

Buying a Dodge is like buying that old Bentley. You buy it, not because of any logical reason ... but because it looks neat or cool to you. You can drive in your Dodge and go "woo-hoo" look at me, ma, show me the blow-your-horn-trucker sign. Honk Honk. Listen to my Cummins, I have a big truck Cummins.

A broch! <!--StartFragment --> A broch tsu mir! My transmission broke? Oy. Whatever.

 

I haven't heard of any Torqushift or Allison problems due to their transmissions, even under heavy work.

 

Just since august will the ford haul more. The previous two years the chevy and dodge would both tow more. Its a truck thing not an engine thing.

Start the tow easier is subjective. You can begin towing with a nv5600 without stepping on the gas pedal. That sounds easier to me. So I would say you are mistaken.

Any high revving engine will accelerate faster. At the cost of making less force. Less force. Less load. If you were to tow 30k with both. Im of the opinion that the MT equipped cummins would do slightly better. More force. More torque at the wheels. Better gear spacing.

 

I would have to disagree with you on your statement of An automatic transmission is capable of more work. Work = Force X Distance. In an automatic transmission the torque converter is the downfall to your statement. Basic laws of physics dictate that a machine can not output more work energy than is input into it. The nature of a torque converter turns a large portion of the work input from the energy into heat energy. This heat energy is a net loss to the total work output of the system. A Torque converter is a simple mechanical advantage. The name "torque converter" aptly describes what it does. It converts high rpm engine torque to a greater torque at lower rpm, in effect multiplying the torque output. In the process of doing this, the engine has to turn the input of the torque converter a much greater distance than the output turns. This results in a large expenditure of Work from the engine with a lesser output of work from the output of the torque converter. All slippage of the torque converter is wasted heat energy. This accounts for inherent inefficiency of an automatic transmission. Some people misunderstand the principles of the torque converter. If the torque converter truely multiplies torque, at no cost, then we should put 20 of them on an engine and we would have a torque monster. It just doesn't work that way. If the torque converter truely gives you something for nothing, You would see torque converters on manual engines. There is absolutely nothing that would stop you from putting one either in front of or behind the cluthch on a manual tranny. The converter is not a positive for the automatic transmission, it is a design neccessary liability. The power plant in front of an automatic transmission has to exert more work energy to get the same amount of output work energy of a manual. The slippage in a manual clutch is extremely short in duration and negligible in heat output compared to an automatic.
Think of the torque converter as a lever on an axis. This is truely what it is. A lever allows you to move objects you can not move without one. But for instance, you would have to move the lever 4 feet to move the object 2 inches. You exerted much more work than simply moving the object 2 inches with no mechanical advantage, if you were capable of moving it with no mechanical advantage.

 

very good ga302p. Nice explanation.

Now my take on this subject. My current ride is an SD with the 5.4 and 4 speed auto. While I like the truck, I hate the auto. I miss my old 5 speed manual trannny. Not for relyability sake, but I just miss rowing my one geras, even i stop an go traffic.

 

Ga not a bad explaination but inaccurate for the most part IMO. The one thing that is correct is heat is the killer in any transmission, be it manual or automatic. But with proper cooling this can be over come. In fact if I'm not mistaken some of the manuals today come with coolers and of course need a pump to flow the fuild. The following is an excerpt from TCI:

"The sprag is a one-way mechanical clutch mounted on races and fits inside the stator while the inner race splines onto the stator support of the transmission. The torque multiplier effect means that a vehicle equipped with an automatic transmission and torque converter will output more torque to the drive wheels than the engine is actually producing. This occurs while the converter is in its "stall mode" (when the turbine is spinning considerably slower than the pump) and during vehicle acceleration. Torque multiplication rapidly decreases until it reaches a ratio of 1:1 (no torque increase over crankshaft torque.) A typical torque converter will have a torque multiplication ratio in the area of 2.5:1. The main point to remember is that all properly functioning torque converters do indeed multiply torque during initial acceleration. The more drastic the change in fluid path caused by the stator from its "natural" return path, the higher the torque multiplication ratio a given converter will have. Torque multiplication does not occur with a manual transmission clutch and pressure plate; hence the need for heavy flywheels, very high numerical gear ratios, and high launch rpm. A more detailed discussion of torque multiplication can get very confusing to the layman as high multiplication ratios can be easily considered the best choice when in fact more variables must be included in the decision. Remember, the ratio is still a factor of the engine torque in the relevant range of the torque converter stall speed, i.e.: a converter with a multiplication ratio of 2.5:1 that stalls 3000 rpm will produce 500 ft.-lbs. of torque at the instance of full throttle acceleration if its coupled to an engine producing 200 ft.-lbs. of torque at 3000 rpm. However, if this same engine produces 300 ft.-lbs. of torque at 4000 rpm, we would be better off with a converter that stalled 4000 rpm with only a 2.0:1 torque multiplication ratio, i.e.: 300 x 2.0 = 600 ft.-lbs. at initial acceleration. Of course it would be better yet to have a 2.5:1 ratio with the 4000 rpm in this example (provided his combination still allows the suspension to work and the tires don't spin.) This is just a brief overview as the actual scenarios are endless."

As you can see they do in fact multiply torque. We know that the PSD is 1.86:1 and that it stalls at 2000-2100 from test people have done on this site. This equals:

PSD:
570 X 1.86 = 1060 X 3.09 = 3275 X 4.10 = 13428

Cummins:
500 X 5.73 = 2865 X 4.1 = 11747

I'm just guessing that the Cummins has 500lbs of torque at 800-1000rpms, but I bet its a little lower.

The PSD has more available torque at the start of any tow, period. Couple this with the ability to lock the converter up and you truely have the best of both worlds. This also confirms and proves that all test done to date that the PSD out pulls the Cummins.

 

I have to make a few corrections. The PSD has to rev to a higher rpm to have less available torque at the start of any tow. You are comparing auto vs manual I assume. Auto vs Auto the cummins has more torque available to the converter. So it will have a higher output coming out of the converter. Reading the tests the cummins launches better. So at the start of a tow. My money is on the dodge.

Its the way high rpm torque works. Slower out of the hole. Faster top end. So at the start of any tow. The cummins has more torque out of the hole. Or faster acceleration. As they go through the gears. The PSD reals it in with its high rpm torque.

I am also under the impression the Dodge tranny now is locking the torque converter. Dont get me wrong Id rather have the TS.

The PSD does not make 500lb ft until 1500 rpms.

I also do not engage my clutch with my engine idling while Im towing. In that article it pointed out that you will rev with a clutch. What it didnt include is that multiplication of that torque would require full throttle for the torque converter to stall that high or at that rpm. So they are also revving the auto. Its a glass half full or half empty scenario. But only looking at it from one angle.

I dont know why people derive one number at peak torque with the auto and assume the manual will launch at idle. If we were to go from 1500 rpm for the cummins it would make as much torque as the PSD at full multiplication. Hell, might as well go for broke. Rev it 100 rpm more and the cummins has more torque at the wheels. Then the PSD will quickly fades to 6500 lb ft or so. Then it does not multiply again. Only during the initial acceleration.

I think MI was mistaken about the rpm that it reaches fluid coupling. Can someone with a 6.0 lock out first and do a full throttle launch? And tell us the rpm it flashes to. I do not think it stalls at 2000. Though I do not own one so this is speculation.
I have to admit doing some experimentation with friends diesels. It didnt appear like they really had much of a flash stall. Or at least really low in the rpm band.

Unlike an auto you can launch a manual at peak hp. I have launched vehicles at better than 4 grand. It is not likely to launch from idle without going for some torque or hp. If you are heavily laiden. It sounds to me like you guys dont drive manuals often. I drive one everyday. Take my word for it. I DO NOT start the vehicles momentum at 800-1000 rpm. So I would not derive my numbers from that rpm. You do not start a manual nor an auto out at idle. You could do it if you wanted. Empty. The cummins is actually programmed to do it with a load. I would not do it with a load that would actually require these torque figures.
So If your gonna pop off with torque at the wheels figures. Dont go from 1000-1200 rpms apart. Its not a realistic example of everyday use. Its not applicable. Its like comparing two engines performance one at idle the other at max hp. Its not going to give you good numbers. junk in. junk out.

 

LH, you are correct that I was comparing auto to manual because that is where the thread was headed. You are also correct that the Dodge auto would also have more torque at the start of a pull than the Ford.

Now do not even think about telling me how to drive or work a clutch, I have many more miles than you ever thought of having behind the wheel. Sure you can launch a manual at peak HP or peak torque but at the expense of eating up clutches like no tommorow. Even launching at 1200-1600 will greatly shorten the life of the clutch. It may not be a fair comparission but that is the way manuals and auto's work. I'm sorry it is a very valid everyday comparrision.

I also think that around 2000 stall is right on. In almost every factory tranny this is about what you get. Sure it goes away fast but in either vehicle you only need max torque in one place and that is to get the load moving. This is why a granny is overkill for the majority of application and users. You exceed the limitations of these truck before you exceed the limitations of the engine.

There is only one place where I'll take a manual over a auto and that is on the farm. I've pull my share of semi-trailers load with hay, sometimes 3 long, low and slow. Maintainalbe torque is what is needed and the manual comes through in this case.

At the end of the day a manual or auto is a personnel choice in most cases. But the days of manuals are numbered. You may not like it but that is the reality. CVT is just around the corner. Todays auto's are very capable and when properly maintained will provide as many trouble free miles as manuals. With the advent of lockup you have mechanical coupling with no parasitic loss.