Bobby,

I'm don't need a measurement from the bed to the frame. I need it from the frame down to the floor. I'll assume somebody else's frame is straight, so the distance from the floor to the frame and these 2 different points really solves my puzzle.

BTW, I have that drawing to and it does show the kickup like you say.

I guess I could just measure my own frame at the top by the front spring hangar and then again at the back spring hangar. Any increase in this measurement is how far the frame is bent up.

?? Why didn't I think of this a long time ago ??

 

LOL...

I'd go measure my 49 for you but I think mine might be tweaked (if it is I don't want to know about it......lol)

You could probably drag a string line along the top of the frame rails (providing you had clear access to it) and might be able to spot a discrepency that way too

good luck

 

That assumes there is no rake to your chassis, which is almost certainly not the case.

Have you got the rubber pads under the crossmembers where they sit on the frame? IIRC there are pads at the front & rear crossmembers too.

Can we see a picture of the C-notch and the reinforcements? If the reinforcing plates aren't visibly buckled, I think it's unlikely the frame bent up uniformly. If you are driving it, do you have bump stops above the axle? Do they show signs of being hit by the axle?

 

Ross,

Rake does NOT matter. It is the difference between the measurements.

 

My bed isn't stock, but don't the 2nd and 3rd bed xmembers meet the frame where the frame kicks up? I seem to recall that the bed xmembers had a slope to them where they met the frame.
When I fabbed the xmembers for my bed I used square tubing. I had to find some angles washers (like they use for bolting stuff to the flange of "I" beams) to make the transition between the square tubing and the kick up of the frame.

My point being....if you cut out the kick-up part of the frame to make your "C" notch then perhaps you created the gap between the 2nd and 3rd xmembers.by removing the kick-up part of the frame.
I'm not sure if I'm explaining it very well. How about this, at the point where the 2nd and 3rd bed xmembers meet the frame, are those areas meeting the original frame or parts of the frame that you have modified to make your "C" notch?

Do you have any pics?
Bobby

 

Okay dude. I'm at my shop and here you go. My truck is on skates on a concrete floor. Bottom of the frame rail at the rear hanger is 24 7/8". Bottom of the frame rail at the front hanger is 19 1/2". I can jack this chassis up and make that difference change, but you say that the rake angle does not matter. I don't see it, but there you go. To me there are just way too many variables there.

And how about those pictures?

 

Shane and all youse udder guys,

It looks like my logic doesn't work after all. I am just going to bend my frame back down at the rear end of the frame rail until the gaps under the intermediate bed crossmembers go away.

I guess what I was thinking doesn't work, but I sure don't know why.

I wonder if somebody here has a frame alignment book with a picture other than the one we've been looking at?

Thanks again.

 

If it were me......

I'd hold off on bending the frame down. Set the bed on there and see how things line up with the cab, etc. Maybe the frame isn't bent at all. If all the body lines look good then I'd add shims between the 2nd and 3rd bed xmembers and the frame.

There is a small chance that you could bend the back of the frame down to make all the bed xmembers line up but then the body might not line up. Step back and take a look at the big picture

Bobby

 

Bobby,
You are probably right. Time for me to go slow before I mess something up.

 

LOL

I have the hardest time with that myself...

 

Looks like the top of the frame rail from the front cab mount to the front hanger for the rear springs is parallel and the same height as the section behind the rear hanger, same as on my 54.