6 Speeds, Where Are They?

[xymbaline]

I'm going to be able to buy a new diesel truck soon, and I want a 1-ton DRW 2WD extended cab with a manual transmission.

I have driven the Dodges and the Fords, but I'll be jiggered if I can find a manual GMC on anybody's lot. I found a Chevy 2500 once with a 6 speed, but it was 4WD and not what I was looking for.

I am also seeing references to flywheel/clutch problems, but since I can't find anyone who has even *seen* a GMC 3500 6 speed, I have no idea what the reality is.

So I could use feedback from anyone who has experience with this configuration.

For reference, I want to buy the GMC over the others, but it doesn't make sense to have to order a truck when I haven't even been able to see how the seat/throttle/clutch feels, or how the ratios work in city driving, where the actual power curves are (like the Ford being punchless below 1800 RPM), and other practical things.

So guys, how would this setup work as a daily driver for someone of average size? What does it feel like?

I will rarely be towing. I just like diesels, (currently still driving an '83 Banks-equipped Suburban with 467,000 miles) and intend to have fun with this pup.

So what's the scoop on GM diesels with 6 speeds?

[Colorado Kid]

I had one, well a 2500HD with a 6 speed, and I liked it. AS I understand it less than 5% of D-max trucks have 6 speeds. Less than half are 3500s and less than 10% are 2WD, so you're looking for a very low probablity truck. (Mine was also 2WD, and I've never seen another 2WD, 6 speed D-max.) My clutch and flywheel were not a problem except for the well documented squeak at the pedal pivot . . . this was fixed with an upgrade part under warranty. I mostly drove the truck as a daily driver, some long trips without a trailer and some towing about 10,000# of 5th wheel.

That 2500HD 4x4 you found would have the same seat/pedals/ratios/power, so driving it would give you a good idea of how it all works.

The d-max makes pretty good power off-boost, but comes on noticibly at about 1800 RPM. It's actually easier to drive smoothly around town if shifted at or below 2000 RPM. When empty, unless you're in a hurry or creeping in traffic, 3 gear starts are routine on level or down grade. The clutch is smooth except that theres a spring that goes over-center on the pedal that can make it tricky at first . . . it kicks you in the foot just as the clutch starts to engage . . .you get used to it quickly. Clutch effort is not bad at all. Shifting (after the first couple thousand miles, when the rubber bushings are too tight) is slicker than any domestic manual tranny I've experienced. Not quite as good as a Toyota or Honda, but very nice.

For the first couple blocks in the morning the throttle is too touchy, and can result in jerking in 2nd and 3rd gears when you try to run a steady speed. This clears up after about 2 blocks, but your kids may laugh at you. :D

If I was going to buy another diesel pickup I'd seriously consider the ZF speed again. It was cheaper to buy, more fuel efficient, faster in the pull-off, perfectly reliable and easy to live with. The only drawbacks were, it made my wife uncomfortable to drive it in tight quarters (Parking lots, etc.) and it may have made it harder to sell, although the dealer said the trade value was equal with either tranny when I traded it. The only other thing to think about is that in the new trucks the D-max only makes 300 HP and 520 ft-lbs (which I found to be very adequate) with the 6-speed while Allison owners get 10 extra HP and 85 ft-lbs for free when they buy the solid gold transmission.

[rickdlance]

Also rememeber the 6 speed / Duramax is down on power a small amount. I have a dealer mechanic who might pay you to buy one if you promise him your clutch and flywheel work. tongue.gif

[MaxACL]

xymbaline

Got one. I've had my 2002 GMC 3500 4x4 for almost three years. Would I but another ZF6?.... Perhaps not. Nothing wrong with it but after several hours in trafic with and with out a trailer, it's not quite as fun. Granted on the road and crusing, IT ROCKS!

My flywheel and PP went South a year ago and the dealer wouldn't touch it under warranty. Learn later they should have and I'm gonna throw out the BS flag to their 800 number.

With 120,000 hard miles on it, I hear noises in the throw out bearing and a bad rumble in the gearing if the RPMs get too low. I pull trailers cross country and I'm scared it will go Tango Uniform again. But... that's what the big bucks are for.

Mike