Question About Frame Strength

Off Road Red · September 11, 2003

As some of you may remember my 99 GMC caught on fire in the spring I am slowly gathering parts to rebuild it and I am going to put a solid front axle kit in from Off Road Unlimited. My question is about the frame, will it be weakened now since it got hot? All of the bushings in the IFS arms are melted, the bumper turned gold and blue so it did get fairly hot. The differential hosing, A/C pump and power steering never melted and they are all alluminum so I don't think it got really really hot. Is there a way to test the steel for strength? Thanks for the info in advance.

Ryan

Shaners · September 11, 2003

I don't think you will be in too bad of shape...

If the steel got cherry red (like from a torch) then the steel could have been affected, but an underhood fire probably wouldn't cause that to happen. Heat rises, and the fire would melt/distort the hood long before it would cause any frame damage...

Off Road Red · September 12, 2003

Well i'm not sure, because all the paint burnt off the front section off the frame, but the alluminum diff housing never melted. I think I am going to use it, if it bends it bends.

revrnd · September 21, 2003

Well i'm not sure, because all the paint burnt off the front section off the frame, but the alluminum diff housing never melted. I think I am going to use it, if it bends it bends.

The frames are coated w/ a wax type material. I imagine it wouldn't take much heat to melt it off the frame.

SalvageZR2 · September 21, 2003

If I recall my metallurgy classes correctly, minor crystalization changes of mild steel should not occur unless it is ~900F (absolute minimum) or above for several hours. The metling point of aluminum is ~1100F. If you didn't just stand by and watch your truck burn while constantly fueling the fire for an extended period of time, you should be fine. Worst case the steel just became slightly more ductile (bendable). I am pretty sure this is correct, but please correct me if I am mistaken (anyone).

I wouldn't worry about it. The only time you would notice is if you wreck it, at which point the frame may bend a little more upon impact had it not been "burned". Keep what you have and forget about it.