What would you do with a bent crossmember in the rear

[Oregon 1967 GMC]

I plan on taking a sledgehammer to it without even heating it up but maybe I should?....
Thank you for any advice.

[midniteblues]

at that point it would either need replaced with a good original and bolted back in with 7/16" grade 8 bolts.

replaced with the correct sized c-channel or rec tube.

or brace what ya have there with angle and hope for the best.

[Grumpy old man]

If you go after that with a sledge hammer your just going to tweak the rear frame rails more than they already are and then your going to have even more damage . Remove it and heat to straighten it back out and then your still going to have to spread The frame rails back apart to get it or even a replacement back in . When the front or rear cross members get bent from dragging them with a chain the member bends and drags the frame rails with it . Measure the distance in front of the bent cross member then measure at the end of the rails , see the difference ?

[Oregon 1967 GMC]

Thanks Grumpy, glad I haven't gone crazy on it yet. I better re-think this. Perhaps a replacement is the best way to go.

[kwmech]

I've got a 72 frame I'm in the process of cutting up.

[Oregon 1967 GMC]

Originally Posted by kwmech

I've got a 72 frame I'm in the process of cutting up.

Wish you were closer, might not be worth shipping. I imagine they're all the same exact size 67-72...

[Grumpy old man]

Member dltruck sells parts and cross members up your way .look him up

[kwmech]

Originally Posted by Oregon 1967 GMC

Wish you were closer, might not be worth shipping. I imagine they're all the same exact size 67-72...

Um, I can remove the cross member

[burnin oil]

Honestly if its a beater or work truck just beat it back to as good as it gets. If you bought the truck and drove it before then it is probably fine even though it is ugly. I have seen a lot worse than that running down the road. My front crossmember had a piece cut out for a PTO driveshaft to a water pump mounted to the front bumper. It was twisting around under load. I just welded a piece to it as a patch and it strengthened it up pretty good. I also have a bent trans crossmember under the trans. I took a baby beater to it to get it as good as it gets. Mine is a daily driver that's hopped up.

[Grumpy old man]

Originally Posted by burnin oil

Honestly if its a beater or work truck just beat it back to as good as it gets. If you bought the truck and drove it before then it is probably fine even though it is ugly. I have seen a lot worse than that running down the road. My front crossmember had a piece cut out for a PTO driveshaft to a water pump mounted to the front bumper. It was twisting around under load. I just welded a piece to it as a patch and it strengthened it up pretty good. I also have a bent trans crossmember under the trans. I took a baby beater to it to get it as good as it gets. Mine is a daily driver that's hopped up.

DON't beat it back to as good as it gets ! Fix it . What's a "baby beater " ??? Hopped up ? What's that mean ?

[Oregon 1967 GMC]

I was wondering that too baby beater, doesn't sound right. THanks for the advice, this truck is worth a lot of sentimental value and since I'm in the process of upgrading it I might as well do it right and get it replaced...I think. I want to be careful about this. I have sent a message to dl truck

[garyd1961]

I replaced the front cross-member on mine because someone had snatched it so hard with a chain they pulled two rivets loose. I just drilled and cut the old rivets out and bolted the new one in.
On yours if I didn't have a replacement I would remove it straighten it and bolt it back in.

[Ruscal]

My truck had the "chain drug" bent xmember too. Maybe someone won a Darwin award by using the old C10 to remove a dead oak tree out of the front yard. It didn't hurt anything, but just looked shabby. I took a small sledge to it, but the metal was stretched and didn't satisfy me. I found a piece of rectangle tube that I reworked for a replacement. It took a little work, but looks good and works fine. My trailer hitch receiver also ties into it for support.
Russ

[Ruscal]

I found a couple of pics, but no good ones of the completed xmember. It is made from 1x3x1/8". I expanded the ends to match the frame channel ID. Threaded inserts were welded into the ends to match up to the existing frame bolt holes. I fabbed the custom hitch to tie into it adding a little strength.

[TrkEnvy]

Originally Posted by Grumpy old man

DON't beat it back to as good as it gets ! Fix it . What's a "baby beater " ??? Hopped up ? What's that mean ?

I'm guessing he is from a construction backround. From my days working as a union ironworker, a beater is an 8lb sledge we used to "beat" bolts or rivets in or flat. A baby beater is prob a 4lb short handle mallet. Sorry for the hijack.

[Oregon 1967 GMC]

Ruscal you may have a future doing that, oh la la looking good. I want to say make me one but I"ll probably take it off and straighten it and put it back in as suggested by Gary. Thanks for the baby beater explanation TrkEnvy and all the helpful replies everyone.

[burnin oil]

Originally Posted by Grumpy old man

DON't beat it back to as good as it gets ! Fix it . What's a "baby beater " ??? Hopped up ? What's that mean ?

Baby Beater is tradesman slang for a mini sledge.

Hopped up means a honest 4-500HP (2 motors) have been between the frame rails in the last 4 years. Putting enough power to the rear to bend the rear leaf springs that I installed when I first got the truck.

None of these trucks have a straight frame anymore, even if it hasn't been wrecked. Don't believe take yours to a frame shop. Even the lowly 6 bangers will have the right side rail tweaked down after 40 years. If it worked fine before you noticed it then it will still work fine tomorrow. Only difference is now you know its bent.

My personal daily driver was a brush truck for a fire department for 30 years. low milage but beat hard. At some point something was hit and bent the trans crossmember just to the inside of the support going to the upper frame rail. Most of the damage was to the crossmember but a small tweak to the frame at the rear drivers mounting bolt also happened. The rocket scientist who repaired it put 5 washers between the frame and crossmember! I beat the cross member back as close as it gets and it is almost perfectly flat now even with the frame tweak. You might get a match book cover in there if you tried hard enough. Good enough for me considering there are 10 more bolts holding it in there. No telling how many decades those washers were in there. Truck drove and stopped straight as it was so no harm in getting it as close to straight as possible. It can only reduce the stress to the frame and bolt holding it. Moral here is the only way it will be 100% correct is to take it to a frame shop and have it all reworked. Then you will find out the body it bent slightly and it wont line up correctly. Sometimes close is as good as it gets because the snowball will never stop rolling once it started.

[Grumpy old man]

Well ... Let me tell you I have 3 perfectly straight short bed frames sitting under my build trucks right now . And a few more in the barn . So saying none of these frames are straight anymore is just horse hockey ! What happens is someone beats them into submission with a baby beater or dumps a 500 honest Hp ? Engine into a frame designed for 1/2 of that without modifications to handle the torque which results in twisted frames and destroyed suspension which you've already admitted experiencing . Assuming this is an acceptable outcome of building a classic high Hp truck is just wrong . Try again .Some of us have been doing this all our lives and it's just not done correctly if your twisting frames and suspension out from under it . I've been in this "trade" all my life and no one in my shop has ever asked if I had a "baby beater " to straighten a frame .

[Grumpy old man]

Oh , and the "lowly 6 bangers" have smoked more built 350's off the line than I can count ! It's all about weight and balance .

[burnin oil]

In my initial post I said if it is a work truck or a beater. If you are doing a frame off resto or full build, by all means replace anything that is bent, partially rusted, or any other reason you can come up with to include modded suspensions.

I can not believe that your frames are straight. They may be real close and good enough but I have never seen one perfect in all directions. Right side is usually low and never perfect in the X measurements. You may have one but it is definatley not the norm. I would almost bet it was off to start and bent straight. These trucks had bad build quality to start with. It was ment to work and not be a show vehicle. I would really like to see a perfect frame, especially since a frame shop can't even do it. They do get them really, really close.

My truck is my truck. I fix it as I brake it. It is a daily driver, a play toy and a work truck. It gets me to work, winches logs out of the woods, through the snow and ice, and anything else I don't want to do to my good truck. If it brakes I have other vehicles. My ride has not been over built yet. That will happen in a couple years when I pull the twin turbo 12v Cummins out of the farm truck. You bet I will straighten and box the frame and add a lot of crossmembers. I know how to build them when I do a full tear down. This truck is not to that point. Keep it on the road and fun is all it is currently. Trust me playing with this little, to me, 72 K20 is within my skill set. It is the smallest thing I own or wrench on. Other rides get a lot more fab work on them.

I was at a shop in Tn where they build logging trucks and I definatley heard them ask for a baby beater there. They were not straightening anything but moving a crossmember back that fit tight in the frame. I have had lots of jobs in my life, all blue collar, and they only one I did hear that term for a mini sledge was at the well diggers. We didn't use anything that small. Definatley did as a mechanic, working on power lines, and few other jobs I have had.

I said my piece now and I know that we will never see eye to eye. I can totally respect your view. This board has drivers and full on builds. Not all repairs need or require the same level of repair. It takes a common sense and a realistic assessment to come up with how to tackle repairs for the desired outcome. There are many ways to skin a cat and as long as its safe we should all make it back to enjoy this board.

[burnin oil]

Originally Posted by Grumpy old man

Oh , and the "lowly 6 bangers" have smoked more built 350's off the line than I can count ! It's all about weight and balance .

Very true. The point was about the low torque and HP of the factory sixes. 200ftlbs + gearing just doesn't brake parts like 400ftlbs through the same gears. I have had them in the past and they drove really well and most never get hopped up. SBC usually get a little hotter when rebuilt but that doesn't mean a race car engine either. Just what people do. I always gained mpg adding a little cam to a stockish SBC build.

Now my inline 6 Cummins with 24 forward gears, 4.44 gears sitting in a 12k lb empty weight truck is slow! Easly carries 5 tons of gravel in the bed and it will pull the house off the foundation but a 4 year old on a tricycle will put it to shame. It can go both ways.

[Oregon 1967 GMC]

Hey guys I really appreciate all the insight. That's what I love about this hobby and being American, we're free to choose as we please. Right now I might just leave it alone ya know "Let that sleeping dog lie."

[Oregon 1967 GMC]

And I still have the original six banger on a stand in my garage if anyone's interested.

[Grumpy old man]

You might want to keep that 6 and include it when you sell the truck . In the not to distant future these old engines will be in big demand by the guys wanting a stock truck . And in the long run stock is where the big money is on any classic including these trucks .

[Oregon 1967 GMC]

Originally Posted by Grumpy old man

You might want to keep that 6 and include it when you sell the truck . In the not to distant future these old engines will be in big demand by the guys wanting a stock truck . And in the long run stock is where the big money is on any classic including these trucks .

and there's not a damn thing wrong with it. Runs like a top, almost regret pulling it for a 400 small block now.