“Big Black” The 2004 Chevrolet 2500 4×4, crew cab, short bed, with a Duramax diesel/Allison tranny combo.
This vehicle showed up at the shop with a 20inch leaf spring and block lift on 52″ Michellin XZLs. It had Superduty axles, lift springs, hangers, sway bars, and tierods. The steer arm from the pitman to the “custom knuckle” had quite the angle with a trac bar to match, not to mention the typical rock-hard leaf spring ride. This bad-ass Chevy was destined for more and comes paired with a driver willing to push this monster to the limit.
This Duramax got a 4Linked coil-over conversion on 2.5 ton military/Rockwell top-loader axles with rear steering and 34 inches of suspension to avoid having the tires contact the body when off-roading on the 60″ tractor tires.
First was removing the old suspension and axles, then clean up the frame by removing the old brackets and mounts.
The subframe main rails were bent up first and then 2 lower crossmembers, and then 4 triangulation braces.
The steering box had to be pulled to be sent out to PSC to be rebuilt and valved for the hydraulic steering assist on the front axle. More about rear steer later.
It was like christmas when the 2 front 2.5tons showed up. Then the de-braking begins…Not fun!!, but shaved around 300 lbs off each axle.
Pulled all the drum brakes off and the axles shafts out to send out for sandblasting. They came back looking like new. Primered them and then pulled the center section to rotate it 180 degrees to have a more centered pinion.
Had to re-drill all but 4 of the “helmet” holes for the 180 degree spin, then welded up the old unused holes.
Next step was to remove factory steering gear box so it could be sent to PSC to be valved to run the front hydraulic assist.