ZF vs. Allison

[Brush Head]

I have decided to go diesel on my next truck. I want a manual transmition and am wondering why the Duramax hp and torque ratings are lower with the ZF tranny. Is it simply a matter of gearing or is the motor "detunned" for use with the ZF?

Also, I have seen two differnt sixth gear ratios for the ZF. What is the real ratio? How is fuel milage compared to the Allison, any difference?

My truck will stay stock as long as I own it and I really want a manual tranny but it should be dependable. Has GM fixed the flywheel and clutch issues?

Thanks allot for any replies. This is a ton of money for a truck but when you consider how much more truck I will have over a half ton crew cab it's a bargin, IF IT WORKS!!

[tanker]

Not sure about different ratio's in the available ZF transmission. I think when you order, you will get what GM offers. The horsepower/torque is what holds you back with the manual transmission. The Allison is computer controlled and along with the engine computer it can manage the HP/Torque, with the manual you are in control, so they lower the limits so you don't hurt the drive line which GM must warranty.
I have driven manuals for many years in trucks and I would only go automatic now. Let the transmission do all the work for me.
I don't know what GM did about the clutch issues of the past, I'm sure some else will be better abled to answer those technical questions. smile.gif

[More Power]

More info on the ZF for the GM 2500HD/3500 applications can be found in the article we did recently on the ZF S-650 6-Speed (http://www.thedieselpage.com/duramax/ZFS-650.htm).

MP

[dmaxmule]

I have a 2005 CC 6-speed and it is great. :D I do not know if it is better than the allison, but it definately takes some practice to get the shifting right. The clutch problem is suposed to be fixed; however, most trucks do not have the updated parts.

As for my opinion I think the allison is faster and easier, but the manual seems to get better mpg.I do not thick that the clutch is heavy (durable/strong) enough for the type truck and the power it has, but the new one may be better.

If you are the type to add accessories, then most all of them are geared for the allison(remote starters, power mods,& etc).

The main thing is that you are happy with your choices for all the different options. There is even talk of a 6speed allison possibly in 2006.

GOOD LUCK :D & HAVE FUN :cool: !!!!!!!!!!!
dmaxmule

[2jranch]

I have an'05' 3500 CC LB and the Allison is an excellent transmission. Look up the link on Allison and you would be "impressed" on how this transmission functions and keeps you operating in the power range. You don't give up anything going to the automatic vs the manual.

[GMC Driver]

As a newbie, I have been going through some old posts to see if some of the questions I have have been answered. This one interested me.

I too would like to purchase a ne D/max in the spring. This hinges on what, if any, types of changes are coming for '06. But if I purchase the D/Max, a stand-alone $6500 option in Canada, I would consider the ZF to lower the break-even point as opposed to a gasser. In addition, it would limit the number of my employees that would be able to drive it, which would work in my favour. The Allison is an additional $3000.

I have driven the D/A combo, (very nice!) and one thing stood out. Reverse seems to be geared very high, translating into slow speed. This is important to me due to the many many hours I spend snow-plowing, with about half those hours in reverse. Does any one know how the ZF compares? Other points of interest include clutch weight, longevity, and mileage comparisons to the Allison.