GMC Sierra Suspension

[DinkADunk]

I'm in the market for a new truck and am looking at the 2500HD diesel (new body style). Anyhow, I'm not able to find a truck configured exactly the way I want but have found a couple that come close. I'm interested in the Z71 Off-Road Package (Z71 suspension, HD locking rear diff, and skid plate package) but did find a truck with the HD locking rear diff and the skid plate package but the stock heavy duty suspension. So the question is what is in the Z71 suspension kit that isn't in the heavy duty/trailering suspension? It looks to be a difference in shocks and something called a bounce jumpers. I'm wondering if I go with the stock and don't like it if I can add the parts later or if it's more extensive than that.

I'm considering towing a 5th wheel and boat (maybe) but know that I'll be towing a small RV trailer (w/ a more rugged suspension) for extended fly fishing trips in Montana, Colorado, and Wyoming.

[iffwalleyes]

The Z71 option is new with the new body style in the HD. I have an 02 durmax that is just the regular suspension. I don't know what the real cost difference it you will probably get a smoother ride with the Z71 suspension as mine does ride like a 3/4 ton. I personally don't think that the Z71 is necessary as most people don't off road enough to require it.

I looked at a new one just last week but with the 46,000 price tag I guess I will wait and enjoy the one I have.

[DinkADunk]

Thanks, the Z71 option include the Z71 suspension, skid plate, and Eaton locking dif $600. The skid plate and Eaton locking dif total 400 and change so the suspension part of the deal is only $200 - I'm figuring shocks. Anyhow, the one I'm looking at is around $54K which is a fairly major wallet biopsy but the GM employee pricing gets it down a lot.

[theoilman]

No suspension info, but diesel engine info. Check the under-hood emission sticker to find out what year the engine is. There are many diesel 07s with 06 engines. I would not recommend an 07 Ultra-low emission engine. The government emission mandates for 07 ultra-low emission engines have caused all the engine manufacturers to use some patches to meet the requirements that many-many-many people feel are a very bad fix. This applies to all highway diesel engines, automotive, pickup all the way through class 8 OTR (over-the-road) semis.

There are way too many unknowns as to the maintenance and dependability of them.

A couple of the things on them: A Catalytic-converter / exhaust-particulate-filter with multiple sensors all tied to the computer - definitely not removable.

30% cooled EGR. (2002-2006 under 10% hot EGR.)

The engine oil - you must use CJ-4, more expensive and because of the additive chemistry limits on it not as good an oil as the older CI-4+ for 2002-06 requirements. (If you use CI-4+ it will poison the catalyst/epf system.)

Fuel economy - I have heard some report much lower fuel economy on 07s compared to similar 06 engines.

Me? I drive an 06 Sprinter diesel, and would not have an 07!

[LMITOUT]

Aftermarket exhausts are already becoming available to remove the factory exhaust that has the particulate filters and catalytic converters. It was only a matter of time.

I agree though, I picked up a 2006 because I didn't care for the looks of the 2007 new gen Chevy's or GMC's and their excessive exhaust components. Obviously it'll only be a matter of time before we can't escape it, but at least I got one of the last "good ones".

BTW, GM recently announced that by 2009-ish they are coming out with a 4.5L diesel that will fit in any GM vehicle that currently has a gasser V8....that could mean Impalas, Corvettes, the upcoming Camaro, and of course the 1/2 ton pickups where it will typically be found. 310 HP and 520 lb-ft of torque! That's how much my 2003 Duramax had in a 3/4 ton package. Should make those 1/2 tons scoot pretty good.

[hawkeye43]

I don't think the 4.5 's are going to have that many hps or torque. There is a big diffence in a 6.6 and a 4.5.

[LMITOUT]

That's what the press release said. Might be in a different RPM range, but it still should be a mover.

The factory ratings don't mean much anyway since there will be aftermarket chips and programmers to take it over 400HP and 700 lb-ft of torque with ease. Gotta love diesels over gas just for that alone. I know I do.

[chickeywing]

The early half ton Z-71's seemed to have softer springs and more travel in the shocks. The suspension travel seems 'smoother'.

[iffwalleyes]

Quote:

---

I got one of the last "good ones".

BTW, GM recently announced that by 2009-ish they are coming out with a 4.5L diesel that will fit in any GM vehicle that currently has a gasser V8....that could mean Impalas, Corvettes, the upcoming Camaro, and of course the 1/2 ton pickups where it will typically be found. 310 HP and 520 lb-ft of torque! That's how much my 2003 Duramax had in a 3/4 ton package. Should make those 1/2 tons scoot pretty good.

---

I have one of the good ones the LB7 is still the best fuel mileage series of durmax they have turned out from everyone that I have talked to. Everyone that I know that had a LB7 and now has one of the new ones said they would rather have their LB7 back. Guess that is why I am in no hurry to change. After all mine only has 158K on it it is just getting broke in . Except for that transfer case and wheel bearing assembly .

All I know is that if they had a 1/2 ton crew cab with a 6.5' box that is what I would rather have but until that happens I will stay with my HD I love the truck.