The Stovebolt Site Forums The Shop Area Paint and Body Shop Frame straight enough? 1950 3100

Hi, Not sure if this question belongs here or in The driveline forum... My truck has been in some kind of accident, there is a lot of bondo on the passenger cowl panel and some damage on the inside kick panel as well. The frame itself looks ok. I don’t see any obvious damage. I put it up jack stands and put a 4 foot level in front of the firewall across the frame. The frame does seem to slope 1/8 to 1/4 inch from driver to passenger side. My question is: how big of a deal is this? Should it be dead level? Or were these old trucks never that straight to begin with? I wouldn’t even know where to start if it needs to be straightened. Thank you

Is the slope the same in the back, and in the same direction? If so, it's probably your floor that slopes. If there's a little twist in the frame, that could probably be taken out pretty easily, but 1/8 to 1/4 is barely enough to worry about IMO. They'll likely flex that much if you drive over a rock with one wheel.

You know, that is a great point. I didn’t even think of putting a level on my garage floor. I’ll do that when I get home. I thought 1/4” didn’t sound like much but I’m glad to hear someone else say it. Thanks

Or, at least put a level across the top of your jack stands. That will eliminate an uneven floor or sloppy jack stand manufacturing tolerances. Think of it as a mobile, poor man's jig table. Then measure frame level, measure diagonals, etc.

The floor is level, jack stands are level, very front and very back of frame rails are level. It’s just if I put the level just in front or behind the cab it slopes about an 1/8 to 1/4 from driver to passenger side....

Isn’t that what shims are for? 😎

I wish mine sloped to the passenger side. Most Chevy trucks lean the other way due to years of driver weight. If you have one that slopes the other way count your blessings!

Ok. So you guys are saying I just need to put on a few pounds. Got it.

Sounds to me like the springs might be the root cause of the slope?

So it's not twisted. That's a good thing.
Brings to mind the Model A coupe that was originally owned by a guy named "Tiny" who sold it to a skinny guy. He swapped the transverse springs end for end, and it then leaned right by at least 4 inches. I bet it still leans right to this day. That was back in the mid 60's.
He had it on jack stands on the frame, so the springs would be out of the equation.

The front and rear springs can affect the way the frame sits at rest. My 59 had a high rear passenger side, until the spring shop re-arced the front driver's side spring... then the entire truck sat perfectly level! Turns out that that spring set was pulling down...enough to lift the opposite corner. Hopefully my experience can help yours.

For the most part, the frame is flat from the radiator cross member to the rear end kick up. Especially on top of the rails. If there is any way you can site down the rail, you'll be able to see if there are any bows or twists in your rails.

Similar to sighting lumber. If you have never done that, this guy explains it a little better than me.

The cab is still on the truck so it may be hard to sight the rail but I’ll give it a shot. I wonder what cause such a thing. Maybe to heavy a load in the bed at some point. I understand what frontstomper is saying, I plan on replacing the springs or going with IFS so I guess I’ll see if anything changes when I remove them. Thanks all

Eye sighting may be very hard to do, and see, in the 1/8-1/4 range. There may be humps, rivets, metal overlap and all manor of features to interrupt sight, unlike a board. Getting your eye down there (with a level head ) is harder than standing and holding a board.

This point has been made by other posters already but here are my thoughts. 1/8 is in the area of level, on a truck that old. You may be thinking there is a "problem" that does not exists. The frame build tolerances, together with metal and rivet fatigue/stretch, would give 1/8 across 34" easily. How are you arriving at the 1/8-1/4 dimension? How are you measuring that? There could be some error with how you do it.

By the time you add the thickness tolerance stack, the fatigue and shrinkage of the hardware/pads that make up cab mounting, you could even be 1/8-1/4 in the opposite direction, regarding your results in checking cab for level. Your numbers, 1/8-1/4 are not abnormal even if you are exact. So my answer is no, you do not have a problem to worry about.

I have a laser level on a tripod that puts out a horizontal and vertical red line after the tripod is bubble leveled. I use that for all kinds of things around the house. This would be a good thing to use in your case if you want to be sure. The sagging springs is a good point. That has to be checked and/or taken out of the equation. (this is the point Mark made about putting frame on leveled jack stands)
A 20% coupon available in many fliers and magazines, makes this $44.
https://www.harborfreight.com/self-leveling-laser-level-kit-69243.html

Thank you. That’s what I was hoping to hear. It sounds like most people on here wouldn’t worry about that small of a difference. After I get it back from the sandblaster I will take a real close look at that rail and just make sure there are no cracks or weird things. Other than that I won’t spend much more time on it. Thanks for all the input.

I would say that 1/8th to 1/4" would fall under the category of margin of error for manufacture and/or measuring method.