Shocks

Have you inspected your suspension pin bushing and torque rod bushings? How is the tire wear? As far as shocks, I am using the Gabriel 89458 GasSLX Shocks, I picked them up on Amazon, $56.31 ea currently, along with the Monroe 65158 Gas-Magnum 65 Shock Absorber, currently $60.78 ea. Both sets are working as they should, no issues with either brand. I haul very light, usually just a few skids, sometimes I do hit 40,000 though, but rare. I pull a 53' dry box. The shocks are going on their second year. Ride is great and tires all wearing normally. No issues.

Also, have you been underneath to inspect the u-joints and carrier bearing?

 

When was the last time you re torqued the wheel bearings in the back axles? That too can give you some odd feedback.

 

I have yet to actually try them but pretty sure you can't go wrong with Road King's....

 

I upgrade my 900 to the AG400 and used Monroe 65158 Gas-Magnum 65 Shock Absorber.

Highly happy

 

From the 380. truthfully I was shocked at the difference it made as I dragged my feet over it. Combined with the shocks better tire wear and ride. Not a big fan of oem shocks.

 

Wish I could have backhalfed it, might have been cheaper. Changed everything out. HOWEVER to be honest mine needed rebuilding anyway so I just ate the extra cost. While your 380 is in good shape and I would try the shocks first that justtrucking recommended. I lean towards the Monroes