Buying new Dmax need some answers

[Ltrainracing]

I am about to buy a 3500 Duramax and have a few questions about what i should buy with the truck. I have never bought a big truck like this, but i do own two corvettes and many different race cars so i am aware of normal performance upgrades and what not. I have a few questions.

1. Crew Cab or Extended cab?

2. What drivetrain options should be ordered?

3.What should I watch out for(parts that break under warranty)?

4. What are the first 4 things you would buy for a new Duramax.

Thanks for any assisstance -Elliot

[HD-Nate]

1) Crew Cab why go part of the way, go all the way, much more comfort and room.
2) If you go with the Dmax/Allison combo, I believe you get all the drive train goodies with the package. Not sure on the ZF 6-speed????
3) Hopefully nothing, some known problems have been leaking batteries, some have had injector problems. Keep the fuel clean, change fluids and filters at or before recommend intervals.
4)
a. Bigger tires, 265 or 285

[Hound]

1. I like the crew cab a LOT better than the '99 extended cab that we had previously. Rear seat is a bit more comfortable and MUCH more accessable.

2. The G80 if you feel it would be useful.

3. Not sure, I haven't had any real breakage. I did replace the NSBU switch with the newer tan one as a preventative measure.

4. I put Bilstein's on all 4 corners as the factory shocks were poor at best. Then got rid of the POS Firestones that were on it. Then got a Kennedy headlight harness. Added a bypass oil filter. Then would be secondary fuel filter, gauges and performance box.

Of course that doesn't cover the fluid changes for the front and rear diffs, fluid and spin on for the allison, fluid for the xfer case, and the oil and filter, all of which took place at low milage intervals for a bit.

For me, all I'm lacking is the secondary fuel filter which I may remedy fairly shortly as I have almost made up my mind on which way I want to go with that.

Welcome to TDP, good luck, have fun and enjoy! smile.gif

Forgot to mention the Amsoil oily couch cushion air filter that was added early on.

Also forgot to mention a GOOD quality strap wrench to get the GORILLA tightened oil filter off.

[ 08-15-2003, 09:34 AM: Message edited by: Hound ]

[chuntag95]

1. Crew Cab - No question about it.
2. DMAX/Allison
3. Leaking battery or injectors.
4. If you want if for mostly towing and plan to keep it a long time -
a. Secondary fuel filter to 2 microns.
b. exhaust and boost gauges
c. 4" exhaust
d. steps if you have a lady that needs them or a power adder and a step ladder. :D
Other items might include a bypass oil filter, bed cover, bed rail caps, spray in bed liner, new tires, better sound system, etc. etc. etc. :cool:

[Amianthus]

I am probably the last guy you should listen to, but what they hey. I'll throw in my two cents.

To answer your questions,

1. That's a matter you'll have to decide. I like my extended cab and will never go back. But you need to determine the role of your truck to decide if you will need the extra cab space or not. Here's a hint, though. Everyone I know that has an extended cab, will never go back to a standard cab.

2. Don't have much advice for you on this one. But again, it comes down to the use of the truck. 99% of the time, the Allison will treat you right and will perform flawlessly. But if cost is an issue, then the 6 spd. is a great alternative. If you are going to modify it, then the 6spd is the cheaper route. But the Allison, when built, is better for drag racing. IMHO, I would stay away from that POS off road package and build it yourself, if you're going to do that.

3. Parts breakage? Outside of boiling the tires away when empty and the flimsy box, there has only been one issue that is of real mechanical concern. That is the failing injectors. Other problems that you may run into are not that prevalent, so I wouldn't lose sleep over it. Use a quality fuel additive (even though Gramma Motors tells you not to), use fuel from a reputable station, and keep your filters in good service. This should help minimize the occurance of an injector issue.
The best advice is to find a good dealership and build a relationship with them. They are worth their weight in gold. Do a search on here and find one in your area that is recommended.

4. Hmmm, good question. Again, it all comes down to application. You need to decide what you are going to use the truck for. That will really point you down the "road to ruin". I consider the following a necessity, though.
Gauges!!! Get them because you need them. Trust me. It will give you an insight into what your truck is doing and what to expect so that once you start to modify it, you will be able notice deviations from the norm.
Exhaust system. Go for at least 4". That will help with spoolup and EGT issues down the road. I am wishing I would've went to 5" but I've got other reasons (issues) to want an exhaust that massive.
High quality, high flow air filter. And I don't mean a K&N. Use the search engine here and find out what works.

As for mods to the truck, I wouldn't touch the thing until I had at least 15,000 miles on the clock. No synthetics, no fueling boxes, no nothing. Just routine maintenance. Get familiar with your truck in this time frame. Let it break in. Trust me.

Once you decide you want to modify it, do some searches on here, attend some get togethers, and talk to a few people who've modded their trucks. Ask them if you can drive it to see how it is (I'd let you drive mine, but it wouldn't do you any good).
Be weary of "fly-by-night" modders that will sell you boxes that they don't completely understand. I've had a few guys come to me about mods done by someone else and now they are having problems (like I'm some kind of expert :rolleyes: ). Make sure you fully understand how it works, and why. Only a reputable mod dealer can give you that (ask me off-line about who I'd choose if you want).

Well, that, I think, answers most of your questions. If not, say so. There are some quality individuals here that will come to your aid if the need arises. And then there are some freaks (no names please). :D ;)

[GMC-2002-Dmax]

Ltrainracing,

1. Crew Cab !!!
2. Dmax,Allison,G80,Z82,Z85, Dual Alternators
3. I Have not had any problems, first off I would get secondary filter for fuel. ( working on getting one myself )
4. First 4 Mods - Gauges EGT & Boost, 4" Exhaust, AFE Stage II, Edge Hot Juice.

Then if $$$$$$$$$$ allows, bigger wheels and tires, quadzilla tuner, and the list goes on.

GMC ;)

[Ltrainracing]

thanks for the info guys it really helps especially coming from people tht have the trucks already. Thanks!!!!!!!

HD-Nate I have a 2002 Z06 and a 01 convertable. I live in the philly area and am a regular at the corvette challenge. I usually go to corvette forum and z06vette.com thanks and talk soon.