'03 2500HD Silverado - Tire/Wheel input and Wieght Request

[shanz3n5]

Good Evening Chevy Adventurists
Original Owner
2003 Chevy Silverado / 2500HD Duramax / 4WD / Crew Cab / Long Bed

I am just about done with the mod of a custom utility bed to fit my FWC Grandby. I will post a build soon. I have a few suspension issues and wheel & tire decisions to make. Positive input is always good on that issue. At this time i'm running stock suspension with front level kit and air bags in rear.
This truck is no longer my daily driver. 212k miles and still running strong. Has been used and cared for well and to its max at times. It is now hopefully going to be now just an adventure / exploration rig. Lots on the want and to-do list. as cash comes in mods go in to truck and camper.
Most of my travel to this point and most likely the future, have been light to moderate off road to get to locations.

Tire / Wheels:
16" stock alum wheel with mich ltx m/s2, 285/70r16 e rated. Strong enough to carry as is empty with camper, 3750lbs @ 80 psi. This is second set of these tires and i have been extremely happy with them. last set 70k miles. A lot of empty wheel well space now with new bed that i would like to fill. Dually adapters wheel and tires or widest tire on deepest neg offset rim i can find. dont really know which way to go. pros and cons??

Suspension:
Dont really want to lift truck but not opposed if need.
As is with no air in bags, she sags. With air @ 80 to bring just above level, she rides rough. 65 seems to be ok, but a lot of sway and lean with bounce.
options i have been contemplating:
going to Deaver and replacing spring packs or National spring rebuild
Front and rear sway bars
Other ideas????
before
last fit check before linex
hard to see but look at wheel well space

look forward to feed back
thanx john

 

[John G]

Hi John,

This sounds like a similar issue that we dealt with on my dad's 05 duramax albeit CCSB. He added 285/65-16's to gain additional load capacity for his massive 5th wheel toy hauler which required cranking the torsion bars for clearance (adding shock extensions) and then using his airbags to level the rear. Result - rode horribly. We ended up adding a 3" sky jacker lift kit and Bilstein shocks. This allowed him to back off the torsion bars and have factory CV angles which brought the ride back but still had the clearance for the taller tires. The kit did desire a new wheel with more offset which caused him to add larger fender flares than factory for coverage. In the back it was just blocks - 2" I think. That meant he didn't need to use the airbags to level it (still had a slight rake) and when combined with the shocks the ride was much better. Not sure how the additional weight of your utility bed would affect this. Just something to think about. I'll look for a pic.

John

 

[shanz3n5]

Hi John,

This sounds like a similar issue that we dealt with on my dad's 05 duramax albeit CCSB. He added 285/65-16's to gain additional load capacity for his massive 5th wheel toy hauler which required cranking the torsion bars for clearance (adding shock extensions) and then using his airbags to level the rear. Result - rode horribly. We ended up adding a 3" sky jacker lift kit and Bilstein shocks. This allowed him to back off the torsion bars and have factory CV angles which brought the ride back but still had the clearance for the taller tires. The kit did desire a new wheel with more offset which caused him to add larger fender flares than factory for coverage. In the back it was just blocks - 2" I think. That meant he didn't need to use the airbags to level it (still had a slight rake) and when combined with the shocks the ride was much better. Not sure how the additional weight of your utility bed would affect this. Just something to think about. I'll look for a pic.

John

thanx John for feed back. i think i will take to a few shops this week and get some input. i can't guess about this as cash is tight. It definitely needs to be correct. A smooth road ride as well as durable off road.
right now unload weight (boxes empty and no camper) im at 8260 lbs.

 

[jdinevens]

thanx John for feed back. i think i will take to a few shops this week and get some input. i can't guess about this as cash is tight. It definitely needs to be correct. A smooth road ride as well as durable off road.
right now unload weight (boxes empty and no camper) im at 8260 lbs.

Wow, whats your GVWR? are the Chevys like the fords in that the 2500s are essentially the same as the 3500s?

 

[topofpalomar]

John,

Lookin' good!

.02 based on my setup:

I had a leveling kit installed that originally included a 1" lift block in the rear. The front utilizes the leveling keys with a moderate torsion bar crank ( as I remember it's about 3" lift in the front). I added air bags to the rear but didn't like the sway. It rode great on the freeway, tho.

I recently removed the air bags and lift blocks and had two leafs added to the rear spring pack. Wow, what a difference. I could drive up the mountain without any sway/lean and the rear didn't porpoise when I hit the cattle guards. But the freeway ride was a bit too stiff. I felt every ripple on the highway. I put the bags back on and inflated them to less than 10 psi. Seems to be a good compromise. Handles the curves and cattle guards with very little sway or porpoising. Ride on the highway is great. Just did a 2,000 mile trip and everything worked fine. Maybe after the rear springs settle in I may remove the airbags again and see how it is on the freeway. I'd prefer to eliminate the air bags to increase the rear wheel travel but for now I'll settle for the compromise.

I felt the stock 16" wheels looked too small after the lift and especially after I had the utility bed installed so I went with 17". I'm running 285-70-17 BFG All Terrain tires now and am happy with the performance. Front tires do tend to throw rocks and mud on the truck so I'll probably go with wider fender flairs like John G mentions. A little tire rub once in a while at full turning but very livable.

Keep us updated on what you end up doing.

 

[John G]

Just for completeness -

Lift kit was skyjacker C9381 lift kit (3" - no shocks or rear blocks), Readylift 2" blocks for the rear, Bilstein shocks (for up to 2.5" in the rear and I think they were for 4 - 5 or 6" up front - recall there were none for 3" so we went one larger to ensure adequate travel). Also has airbags in the rear - see pics below. On 285/75 - 16's.


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John