Hi everyone,

I'm going to be purchasing a 2500HD with a Duramax within the next year. I have a 2001 Z71 right now. I hardly ever use the options that I have on the truck, so my next one will be a plain-jane extended cab 4x4. All I'll get for options is A/C, CD & Cruise. I don't even want carpet or cloth seats.

My questions.. All you guys with the 6-speed, would you do it again? Is the MPG better than the Allison? Why does GM de-rate the 6-speed d-max at less HP & torque than the Allison, to sell more because the Allison is more expensive? Would it be easy to re-program the d-max with the 6-speed to put out the same amount of HP?

yes I would do it again. handshaker is my thing.
less HP because the flywheel wont hold and they are having problems with them.
you can add all kinds of power to the 6-speed tho.
welcome to the site

I wouldn't even look at a new one without the 6-speed. I love mine, even though the clutch is slipping and the flywheel sounds like its about to explode. Tha clutch problem came about because of hot juice and my foot, but the flywheel hasn't been right since it was new, u might won't to look into that before you make a descision. Plus, every allison owner that ever drove my 6-speed said thats the way they wish they would have gone.

I will buy an automatic transmission when General Motors quits offering a 6 speeds or after they amputate my left leg. I ain't that old where I can't shift it when it needs shifted. I wouldn't own an automatic unless it's a rifle or handgun.

Jim

What about MPG? You must get better MPG than the Allison, right?

I've got to be honest. I've driven a Dmax Alli only once. Reread Stormcloud's post that's me too. I think because we are a minority we are pretty much diehards. I need a bench for my family of six, I like the 6 spd, why not save a bit of money.

I'm not sure on power. With an LLY ZF derated is a 60Hp box plus 60 or plus 60 over an LLY/Alli rating???? That makes a big difference.

I love my six-speed... It keeps the wife out of the driver's seat:rolleyes:

Even though the allison is supposed to be incredible, I jockey cattle around from place to place and a six speed will run all over the allison on the interstate. Also, it might just be me, but under a load the allison downshifts so hard that you know it can't be good on tha trans. Its just like droppin a gear in the ZF-6, but without as much help from the brakes.

I love my six-speed... It keeps the wife out of the driver's seat:rolleyes:
ditto :driver:

:lol: Walking into the 6speed forum and asking what these guys think about an auto is like going into a ford site and asking em what they think about the duramax:eek: Go over to were the auto guys hang and ask what they think of sticks?;) :D

I bought an allison for one reason.....I plow snow. I may have considered a dodge when i bought my new truck but then I woulda had to get a dodge auto-:t If i didnt plow I actually though about getting a stick. I duno what way I woulda went. I may have actually bought a dodge:eek: But looking back I am very glad i bought what i bought. I love my allison. Not only for plowing but also hot rodding. Not many stick trucks that can hang with my truck at the strip. Allison does give up a bit in MPG I assume just becuase its inernals are huge and it takes around 50hp to turn it.

in 06 the allisons will be 6 speeds too and will be set up were they have an "auto stick" type deal like the dodge cars.:cool:

The 6 speed trucks are detuned to keep from tearing up stuff. Flywheel is the first to go, trans itself seems strong. If you get the modding bug though a upgraded allison acts like stock normally, a upgraded clutch can feel a bit different. May matter to you or it may not......

Pretty much personal preference most of the time. Very few times when a stick or an auto would be a hinderence to you, maybe one would be better than another or a slight PITA but not a hinderance. Plowing snow and drag racing are some of the few things I can think of were you really need an auto. Cant think of anything were a stick would be much better?

[QUOTE=gyro94 All I'll get for options is A/C, CD & Cruise. I don't even want carpet or cloth seats.

My questions.. All you guys with the 6-speed, would you do it again? Is the MPG better than the Allison? Why does GM de-rate the 6-speed d-max at less HP & torque than the Allison, to sell more because the Allison is more expensive? Would it be easy to re-program the d-max with the 6-speed to put out the same amount of HP?[/QUOTE]
I did what you are considering doing. I purchased plain jane a/c,4x4 with vinyl seats 6 sp. After The first couple of years I added remote power locks and heated seats[cheap and worth the money]. I love the 6 speed, hate the dualmass flywheel. If I was to do it again, I would go with the auto if GM didn't have a real fix for the flywheel. Even though it is warranty for 5 years it is a pain everytime it goes. I think due to the low volume it is not at the top of the list to fix. They have had almost 5 years of building them and I don't think they have it fixed yet IMO.

Cant think of anything were a stick would be much better?
would the stick be better at pulls?

I duno exactly......I dont pull. Look at the results though, tomac and some other big dogs do alright with thier auto's. Auto would be much easier to pull with but a good driver??? I would still think auto would be better but I duno

are there any guys on here with mods like yours who have the 6spd? stacking programmers and such? what are they running compared to autos? you really have me wondering if there IS an advantage to the manual now that the allison made it's way into our pickups.....

duno if anybody is running a stick with the extreme? dont think so........craig ran a big stack IIRC. I duno what he was running time wise? With a turbo diesel in a drag race you need to have a BIG HP advantage with a stick + be a good driver to hang with an auto.

I love my zf and when I order my 06 it will be a ZF again. The only thing I'll do different is a crew cab instead of the extended cab.

gyro;
here is somthin to consider. If you are just gonna drive back and forth and don't expect to make any power mods, or some kind of competition, or extensive haulin and you are not a lover of hand shakin, then go with the Allison. It is a great tranny.

If you want to do somthin else then you must consider the cost of upgradin either the Allison or the oem dual mass flywheel and clutch (made by "bad"- LUK). CPMac makes a couple of upgrade kits for the zf6 and they cost 1600 to 2300 plus install (unless you do it yourself). If you don't want to do an upgrade you can just expect to take it inot the dealer and have him replace the flywheel several times. the tranny is very stout and will not fail. IOnce upgraded, the zf6 lets more rwhp thru than an allison but is slower to drag race due to manual shiftin.

The allison will not fail unless you make a significant power mod, then it will limp and eventually toast some clutch packs. Allison can be upgraded to several levels. The best is probably the ATS with co-pilot and lvl 4 (?) for about 3500 plus install. this is a much more complicated install and more costly.

i have seen my CPMac dual disc kit installed twice and it is simple enough to do yourself. If you are a gearhead, or have a buddy who is, you can probably do the ATS, Transgo, or Suncoast upgrade yourself. If you get ATS to do it the install will be 3000+

Your decision is gonna be based on what you want to do and what you want to spend, and how important shiftin is to you. Vast majority of dmaxers have chosin the Allison because it is easy to drive and they don't have the coordination to do manual shiftin, IMHO :~)

good luck

and they don't have the coordination to do manual shiftin, IMHO :~)


now, i know your joking because of the smiley face, but a lot of people really do think that. i mean, it's worst than being a brand-loyalist. it's the kind of people (ricers) that look at a 1991 honda accord and say to themselves "well it's only 1.6liters and only makes 65ftlbs of torque @ 65,000rpm, but at least it's a manual!!!!"

i just keep it to myself. im content in knowing that the only thing i will see when we race is their headlamps bobbing up and down while they furiously shift their way to failure.

there's a manual transmission and the slip-o-matic, then there's the allison. usually only people who own one know that the allison is the better choice (all around and imo)

I've been pretty happy with my six speed other than the clutch and flywheel. Those two components are why I wouldn't buy another though. I do like having a manual tranny for pulling and off-road driving, and I like the feel of having complete control of shifting, but, my dads 01 duramax with allison has 150,000 miles on it, with very little problems. If GM could get a good flywheel and clutch that'll handle the LLY power, I would definatly buy another...well, maybe..the six speed allison sounds really sweet!!:ro)

J-HEFF

Hell yeah I'd do it again! Remeber it's a MANual transmission :)
Plus real trucks have 3 pedals and two shifters and no spark plugs.

I like the autos but I will say that my 6 speed will run all over the Alison in the hills. My 2003 LB7 beats my buddies 2005 LLY towing about the same weight up the passes here in Colorado hands down. (Detuned or not theres no doubt the ZF puts more to the ground). I'm on my second flywheel but it's on GMs nickel for now so who cares. When it's on my nickel I'll go single mass and never worry about it again. Otherwise the only thing I suggest is an exhaust brake if you do a lot of heavy towing, I'll never be without one out here now that I've got one.

I second Crawler Hauler, I have ran past a few Alli's pullin my 50ft lowboy hauler loaded with 3 cars going to Aspen and they are only pullin a little baby 36ft 5thW...and especially any Ford or Dodge that happens to get sucked through my intake as I pass them up!! You can only imagine the looks you get when 50ft of trailer and 3 cars rolls by a Ford with one of those dumb I eat Chevy's sticker on the rear window!! Seems like I get a little better fuel mileage pulling according to some of the chat's in here than the Alli's which is usually around 10-12mpg with the above mentioned load. Like most I'm on flywheel/clutch #2 and working towards #3...flywheel's squeel'n again. I especailly like the ZF-6 in offroad conditions, I prefer the control going downhill. As far as mod's and 1/4 mile times generally the Alli's have us beat...so we'll give'em that one for now. I say "keep on grind'n gears ZF-6 brothers!"

I have a friend with the allison and the same dyno dominator package as I do.It takes me awhile to catch him from a dead stop but I can.If were going 45 or so I can pass him and pull away?Now my flywheel and clutch are all done and his allison is too.I dont know what will happen when we get fixed up.One other problem I have with the zf is at @ 65 or so shift into 7th but it is not 7th its 5th!!!!WHOOOOOOPS!!!

I wanted a stick, but i couldnt find a 2500HD Crew Cab with a stick... o well i love my allison

I like my six speed, but the dual disc is not real smooth for pulling the trailer. I went with an ally in the new truck mostly because I didn't want a detuned truck with a junk flywheel. I'll agree that the six is probably better for haulin' than the ally, but I am hoping the ATS will help out. As for sled pulling I think the ally is an advantage for the amount of HP the Dmax can produce as of now. I will report after the ATS goes in and let you know on my impressions.

"keep on grind'n gears ZF-6 brothers!" :thumb:

I like driving manual vehicles in common but I couldn't find a 6 speed when I was looking. Its kind of hard to find one with leather and every other option. Now that I have an allison I would not even think of getting a 6 speed unless they would go back to the regular old type of autos. I would like to drive a 6 speed someday though. I love my allison. Just my .02.

I have the same 6 speed in my Stroker as you guys do. Wouldn't trade it for the world. I drove an auto and a stick in all three brands before I bought mine. I am die hard ford, but they are all good trucks. I liked the stick better than the auto in every pickup whether it be the cummins, duramax or powerstroke. The only weak links are the flywheels and clutch sets. IMO its cheaper to beef up a 6-speed than an auto. :ro)

[QUOTE=. . .. . . IMO its cheaper to beef up a 6-speed than an auto. :ro)[/QUOTE]


very true. . . . my CPMac's single mass/dual disc is hard to shift from a stop in traffic but it is so stout !! There is a dyno day here on April 16th and I should have a lot of power to test how stout the engine/tranny/clutch are. Check the events forum after the 16th and you will see the results.

I like the autos but I will say that my 6 speed will run all over the Alison in the hills. My 2003 LB7 beats my buddies 2005 LLY towing about the same weight up the passes here in Colorado hands down. (Detuned or not theres no doubt the ZF puts more to the ground). I'm on my second flywheel but it's on GMs nickel for now so who cares. When it's on my nickel I'll go single mass and never worry about it again. Otherwise the only thing I suggest is an exhaust brake if you do a lot of heavy towing, I'll never be without one out here now that I've got one.
The Allison can hold approx 125 extra hp from stock without doing damage or limping it unless you really beat the hell out of it.

ZF-6 clutch and flywheel can rarely handle the stock power of the d-max and that's with it being de-tuned from the factory.

Replace the clutch and go to a single mass flywheel and there is no doubt that the ZF-6 puts out more power, I know, I helped install deadeyes clutch and the difference in how the power felt getting to the ground made me second guess getting a Allison, but as soon as I did my ATS upgrades I wouldn't look back!!!

The Allison can hold approx 125 extra hp from stock without doing damage or limping it unless you really beat the hell out of it.

ZF-6 clutch and flywheel can rarely handle the stock power of the d-max and that's with it being de-tuned from the factory.

Replace the clutch and go to a single mass flywheel and there is no doubt that the ZF-6 puts out more power, I know, I helped install deadeyes clutch and the difference in how the power felt getting to the ground made me second guess getting a Allison, but as soon as I did my ATS upgrades I wouldn't look back!!!

yea Wade, :exactly: once you get your t-converter replaced (again) :lol:

LOL, I knew that one was comming!!

So how's you clutch doing on it's second install??? still have that thin disk??? sure wish Craig had spaced it right the first time huh!!! LMAO!!!!

Just kidding John, having the truck down does suck but just like with your first clutch from Craig I just had a minor setback. And like you I'm glad I'm not doing the labor the second time around!!!

[QUOTE=. . .. . . IMO its cheaper to beef up a 6-speed than an auto. :ro)

very true. . . . my CPMac's single mass/dual disc is hard to shift from a stop in traffic but it is so stout !! There is a dyno day here on April 16th and I should have a lot of power to test how stout the engine/tranny/clutch are. Check the events forum after the 16th and you will see the results.[/QUOTE]
Do you mean the trans is hard to shift? Or do you mean its hard not to kill it from a stand still? I'm dying to get a single mass/single disc or dual disc, but can find one anywhere. I need one that will do a 4th gear - 4-low take off in a truck pull. 3rd gear - 4- low isn't a problem, but it still slips the stock clutch a little to much. I dunno if a single disc will hold it, but I know a dual disc will. I just have to sacrifice driveability to much cause I haul heavy loads.

Deadeyes truck will do a 4th gear takeoff in 4 hi on the pavement, I don't think 4 low would be a problem.

I'm sure it will when there is no sled behind it! Mine does a 4th gear take off on pavement too when its empty and no sled LOL

We were doin 4 high launches in it:eek: .

You did a 4-hi launch with a sled or in a drag race?

You did a 4-hi launch with a sled or in a drag race? My guess would be neither...just goofing off.....http://www.dieselplace.com/forum/images/smilies/biggrin.gif

Sounds that way :ro)

Sounds that way :ro)

The launches I did were on the street. I have not done any since I got Super Diesel's center link bar on. Still waiting for some add-ons to arrive.

The shifting is stiff and slow compared to stock and on race cars. CPMac's kit makes it a little stiffer and the clutch pedal is a lot stiffer. The main challenge is 'launching' on the street from a stop lite, esp behind a gasser or rice burner :lol: because I have to start slowly with reduced rpms. This makes the clutchs squeal and the truck jerk because the clutch is so grabby. At higher rpms the launch from stop is easier. Doing a little intended clutch slip in forth gear from low speed will smoothe the clutches and make 'launch from a lite' much easier, for a while. This his minimal, if any, impact on the clutch plates, according to Craig.

Can you imagine launching from a complete stop if you clutch was a gear, instead ?? :exactly: This is what it is like. Craing indicated that shiftin you should not slip the clutch from gear to gear as it will eventually wear the discs. This is another reason why a hand shaker would be a disadvantage at a drag race. . .

I have a couple ideas to improve the speed of shiftin to investigate. If I learn anything of value I will post results.

And just think, those standing still 4rth gear launches are with 35" tall tires. :eek:

Deadeye if you could pull the quater starting in 3rd then shift into 5th or 6th, the shifting might take longer but you would only have to shift it once. :ro)

And just think, those standing still 4rth gear launches are with 35" tall tires. :eek:

Deadeye if you could pull the quater starting in 3rd then shift into 5th or 6th, the shifting might take longer but you would only have to shift it once. :ro)

Trust me :D I have thought about this and will do some testing once the rest of my add-ons arrive :driver:

What do you guys think it would take horsepower wise to do a 4th gear 4-low launch in a sled pull. I had a banks six gun and speedloader and was doing 4-low 3rd gear with no problems. I got rid of that and went to the edge juice/attitude and am also adding a Stackable SCT from Innovative Diesel. They are guessing it will make 450 RWHP. My clutch is finally ready at south bend. Cermetallic on both sides. Single Disc. I know with a ford you have to slip it and stay on the uphill side of the turbo. Is GM the same way? I know its not a problem on a cummins.:ro)

What do you guys think it would take horsepower wise to do a 4th gear 4-low launch in a sled pull. I had a banks six gun and speedloader and was doing 4-low 3rd gear with no problems. I got rid of that and went to the edge juice/attitude and am also adding a Stackable SCT from Innovative Diesel. They are guessing it will make 450 RWHP. My clutch is finally ready at south bend. Cermetallic on both sides. Single Disc. I know with a ford you have to slip it and stay on the uphill side of the turbo. Is GM the same way? I know its not a problem on a cummins.:ro)

Hard to say since I've not done any sled pullin and the last Ford I owned was 460 gasser. There is a Ford forum on this site. Maybe ask them ? Have not seen many pics of Fords duin pullin.

I wouldn't even look at a new one without the 6-speed. I love mine, even though the clutch is slipping and the flywheel sounds like its about to explode. Tha clutch problem came about because of hot juice and my foot, but the flywheel hasn't been right since it was new, u might won't to look into that before you make a descision. Plus, every allison owner that ever drove my 6-speed said thats the way they wish they would have gone.
not me, the allison rocks over the 6 speed anyday, especially if you mod it somewhat. faster, quicker and better to tow with...

OK, so here's a dumb question. What is the difference between a single or dual disk clutch. I realize the dual will hold more power, but what are the driving characteristics like. Stuff like leaving from a red light, how hard does it shift while driving on the highway and stuff like that.....??

Zorg:
check post #9
http://www.dieselplace.com/forum/showthread.php?p=521039#post521039

And I even read that last night and obviously it didn't sink in. Thanks Deadeye!! So what I'm gathering is the single disk is a much better choice for stop and go driving yes? I don't pull very heavy loads and drive mostly empty, but need the hookup. Single disk is for me?

And I even read that last night and obviously it didn't sink in. Thanks Deadeye!! So what I'm gathering is the single disk is a much better choice for stop and go driving yes? I don't pull very heavy loads and drive mostly empty, but need the hookup. Single disk is for me?


:exactly: