What to look for when buying a used truck with camelback suspension?

[giannid]

So I'm looking at an ex refuge truck to convert to a dump truck.  The truck is a MR688 and it has a camelback suspension.  Not really familiar with this type os suspension but know it can be pretty expensive to rebuild.  Anyone know what to look out for in this suspension.  Dealer says they have a towmotor they can pick the rear up.  I'm sure it'd be a lot easier to see if the suspension was wore out while driving it loaded.  Just looking for some pointers.

[Lmackattack]

look at the spring end caps. are the springs centered? or almost touching the box?. is the trunion bushings tight? or pushed out?. track rods good? look to see if bushings are rubber or upgraded to urathane. when its loaded and you turn do the axles stay put or walk sideways.

 

look for rust and rot at the lower trunion. patch welds? look at frame rails where trunion bolts to for rot. 

 

 

[JoeH]

Camelback suspension is about the best you can have for offroading. Provides perfect weight distribution to all 4 wheels at all points of articulation, regardless of how fast you're going over rough terrain.

Air suspension articulation requires time for air to vent from one bag and the truck to fill the other bags. By the time it's done that you're three bumps ahead of where you were or you're stuck.

[JoeH]

Truck should have 3 Torque Arms, one from the top of each axle tying to the trunnion stand cross member, and the third Torque Arm goes from the rear drive axle to the right frame rail.  The joints of the torque arms wear out, expect to replace one or two of them.