Thread: Defender snapped chassis WHAT THE!!!!

Its a design problem of coil spring designs and the cantilever effect of the load over the rear of the chassis where there is absolutely no support behind the coil spring mount. Any weight on the rear of the tray is pivoted off the coil mounts stressing the chassis in front of the axle.

It would never happen if the rear springs were elliptic leaf springs. It is why the Leaf spring Nissan Patrol cab chassis have a 170Kg higher load capacity than the equivalent coil spring model, when everything else is essentially the same.

Originally Posted by Lotz-A-Landies

It would never happen if the rear springs were elliptic leaf springs. It is why the Leaf spring Nissan Patrol cab chassis have a 170Kg higher load capacity than the equivalent coil spring model, when everything else is essentially the same.

The leaf rear Patrols cracked the chassis in front of the front hanger too.

I guarantee they do it less than 130s

We've all heard of numerous reports of cracked chassis with many (all??) brands of dual cab utes and the root cause of all of these failures is overloading.
Utes were originally designed to carry goods, not people so when provision is made to carry extra people, the goods carrying capacity is compromised, and cannot be overcome by extending the tray a ridiculous amount beyond the rear axle.

Originally Posted by Lotz-A-Landies

I guarantee they do it less than 130s

How much do you wager?,I worked for a company called machinery maintenance that had 6 Patrols,5 snapped in half,including mine . Pat

Originally Posted by Xtreme

We've all heard of numerous reports of cracked chassis with many (all??) brands of dual cab utes and the root cause of all of these failures is overloading.
Utes were originally designed to carry goods, not people so when provision is made to carry extra people, the goods carrying capacity is compromised, and cannot be overcome by extending the tray a ridiculous amount beyond the rear axle.

Agreed, overloading is the issue, but the GVMs should have a safety margin built in, and if the Utes aren't up to spec, the manufactures should specify an on road GVM and off road GVM. I expect my 130s to be driven for work at the GVM over terrain that most 4wders go looking for on weekends, in relation to chassis issues and loads, the only issue I've had is from incorrect tray mounting by body builders, now I've got a system in place that all my trays are built to and I've had no issues even in extreme loads and conditions.

Originally Posted by Summiitt

Agreed, overloading is the issue, but the GVMs should have a safety margin built in, and if the Utes aren't up to spec, the manufactures should specify an on road GVM and off road GVM. I expect my 130s to be driven for work at the GVM over terrain that most 4wders go looking for on weekends, in relation to chassis issues and loads, the only issue I've had is from incorrect tray mounting by body builders, now I've got a system in place that all my trays are built to and I've had no issues even in extreme loads and conditions.

I think even on this forum there are thread(s?) where cab chassis owners have found issues and chassis cracks, or gone to great lengths to avoid same in their build process - all linked to incorrect tray mounting.

If not mistaken, in one of nuggets build threads he gives great detail of his efforts to ensure no problems with tray mounting causing chassis cracks

Summiitt,

Unless guarded would you mind sharing your technique of tray attachment longevity?
My old 130 has cracked its front mounts again, my current preferred solution is to find a tdci and start afresh
But seriously I am looking to regrade to a tdci and have been musing on tray design to prevent cracking.
Even contemplated a spring mount similar to earthcruisers to allow some flex between tray and chassis...

Steve