GM Truck Frames: Taking 'Flexibility' Too Far?

It came out in an offhand remark during a Detroit automotive television talk show. A journalist let fly that he'd heard a rumor General Motors Corp.'s new pickups were experiencing bent frames in non-demanding circumstances.

The story goes like this: GM's all-new GMT800 pickup frames were being bent on vehicle transporters. The rumor took on steam when the tale expanded to say the doors of pickups being jacked up - for instance, in a typical tire-changing scenario - wouldn't close properly after the procedure.

GM denies the jacked-up-truck angle, but did issue a statement admitting to frame-bendings of trucks under transport. And although skeptics immediately pointed to the all-new hydroforming process, only a portion of the GMT800 frame - the front rails and engine crossmem-ber and front "crush caps" - is hydroformed and thus is unlikely to be involved in any broad chassis durability concerns like those suggested by the rumors.

GM's statement claims the company long ago corrected improper shipping procedures by a carrier. The problem could've been a setback to one of the most important launches in GM's history.

The automaker says only 36 Silverado/Sierra pickups were damaged last summer when it began delivering the vehicles to dealers - because employees for the transporter were improperly securing the pickups to trailers, causing the center "module" of the three-part chassis to bow. Hydraulics, rather than the manual tie-down procedure specified by GM, were used to secure the pickups. The automaker says that caused damage to the GMT800 frame because the pressure exerted against the chassis was three times greater than usual.

The carrier likely was continuing to use the hydraulic tie-down procedure employed for the GMT800's predecessor, the GMT400, which is secured differently.

GM says it retrained the carrier's employees to correct the problem. And the transporter purchased all of the damaged pickups for an undisclosed figure. There have been no more occurrences, GM insists. A company spokesman points out similar transportation issues have happened previously. "We had the same problem with the (GMT)400, where frames were damaged early on in shipments to dealers," says the spokesman.

Skeptics remain, pondering how trucks earmarked for rugged hauling, supported by a frame that GM says enjoys marked increases in torsional and lateral stiffness and is "stronger, stiffer and lighter," than that of the previous-generation truck, can be damaged by over-aggressive haulers.

And WAW plans to jack up the next couple of GMT800 trucks it test drives from GM. Just to be certain.