Ag380 swap

AG380 is a completely different suspension than the AG400. Its going to be more work than its worth IMO. Frame will need to be re-drilled to mount the hanger on each side as well as the air bags. Torque arms mount differently so you'd likely have to replace some crossmembers too. The lower bag mounts for the 400 will need to be welded to the axle as well as the brackets to bolt the waffer bars to as the 400 doesn't use u-bolts IIRC.

 

That would be an expensive and overly complicated swap. Park next to a truck with ag400 and compare the rear-ends. You would almost have to swap the rear-ends with the suspension, and still be left with the nightmare of redrilling the frame and dealing with a mess of null holes.

 

The real question is why would you want to go to 8 bag

 

Have you looked at a 380 closely? They are junk! With that half moon spring and boxy spring bracket that eats bolts. The quickest way to swap to the 400 is do a cut off swap. If you don't mind your frame having a weld on each side.

 

The flex air has been around for a long time, The only complaint i hear from my friends that haul heavy with it is that the bags don’t have the best lift capacity.

 

And it is only rated at 38000 lbs. It was a poor design to begin with. Kinda like the wishbone bars were when they came out.

 

Don't get me wrong, I like kenworth but why do they have to make every rear suspention so overly complicated?
They almost all ride like crap and wear parts out.

What's wrong with just 4 big bags like airliner or Hendrickson. Ride really good, handles excellent and tough as nails.

Every 8 bag setup kenworth had was terrible IMHO. Except maybe the ag100. But then that would lean like crazy in the corners if loaded heavy.

I love my airliner in both my stars.

 

8 bags ride rough as a pallet of bricks just so you know