Mack Truck Frame

[cfd511]

So this could already be a topic but I'm in a rush. I've been looking for a 10 wheel dump truck and finally found one. I located a mack 686 which has a brand new motor and new tranny. Truck is in great condition until I looked at the frame and thankfully found that the frame between the rear drive axle is cracked length horizontally where the top of the rail bends inward. This is on both sides. I'm asking all you professionals on here can it be welded ? If not , is it cost effective to get both new rails or just the last 8 feet. I called pg adams and they asked if the frame curves under the cab and I had no idea. Like I said, the truck is in really great shape besides the frame and I can get it cheap. Any insight would be grateful.

[Timmyb]

My mate has a truck with the same cracks. 

I haven't seen anyone repair that type of crack. But to weld a new section shouldn't be too difficult. 

Nake sure you get someone who knows what he's doing. 

[ekennedy21]

Donovan equipment will put new rails from behind the cab for $11 grand. $14 if the suspension need to be rebuilt

[TeamsterGrrrl]

Run, don't walk, away from this truck! "686" means this is probably an E6 with an engine mounted aftercooler, last built in the 1980s. The seller is probably lying, barring old stock laying around there are no new engines available for these trucks, and at best it's a rebuilt. The frame is toast, and would need total replacement, which as you can see, easily gets into 5 figures for the frame rails alone, never mind a couple weeks labor. So even if this truck were a gift, I'd part it out!

[cfd511]

thanks for all the replies. i'll be walking away from this truck, far away.

[BillyT]

Appear to be stress cracks, from long hard use, likely other issues would appear even if you replaced frame!