The Stovebolt Site Forums The Shop Area Paint and Body Shop Checking how out of level my cab is

I am sure this topic has been done to death but in case it helps others here goes...

I finally found my laser level and decided to do the calculations and see just how out of level my cab was. Not a horribly complex task but enlightening all the same. Just looking from the front it was obvious it was leaning down on the P/S side.

According to the FAM the top of the top hinge hole should be 38.41 inches above the zero line, or 27.41 inches above the top of the frame (which is itself 10" above the zero line).

Results were as follows:

Driver's side: 27.75 inches or 0.66 inches too low

Passenger's side: 27 inches or 1.41 inches too low

Looking across the floor from the driver's side there is a VERY notable valley in the middle, up to an inch.

The photos tell the story. In the first two, (DS) the laser hits the firewall at 28 1/8" above the frame and the hole is 3/8" lower, at 27 3/4" (27.75").

In the next two, (PS) the laser hits the firewall at 28 1/4" above the frame and the top of the hole is 1 1/4" lower or at 27".

The final two show the floor valley and the laser level on the firewall.

I located a much better frame which should be here later in the week when I will switch the cab onto it, make it level by means of two threaded rods and start in on the floor pans and D/S front mount.

The P/S front mount looks fine but judging by these measurements something is amiss!

Not sure why the images are not displaying but instead show a clickable link???

[img]http://6984wo980.s3.amazonaws.com/DS-laser.jpg[/img]

[img]http://6984wo980.s3.amazonaws.com/DS-hole.jpg[/img]

[img]http://6984wo980.s3.amazonaws.com/PS-laser.jpg[/img]
[img]http://6984wo980.s3.amazonaws.com/PS-hole.jpg[/img]

[img]http://6984wo980.s3.amazonaws.com/laser_level.jpg[/img]
[img]http://6984wo980.s3.amazonaws.com/floor_valley.jpg[/img]

Put some air in your tires.....



I would go by the factory assembly manual readings between the rear schackles and frame. shim as needed

Sounds like you are having a blast with your laser level. Can't blame you, they are pretty cool.
I don't think that it will be particularly useful for checking the position of the cab as it relates to the frame. The laser can show the cab to be perfectly level, but if the gaps between the frame and each of the 4 corners is not within specs, you will have front clip fitment issues.
Cab adjustment is best accomplished as per the Factory Shop Manual. The frame needs to be checked for straightness if it is in question.
Carl

That would put the frame out of level to put the cab into level...

Unfortunately shims won’t fix this. The 1” inch valley in the floor indicates bigger problems are at hand.

I will post an update once I get the cab leveled and squared up.

Thanks but looking at the FAM I was under the impression that measurements were taken with respect to a zero line 10” below the frame. Assuming a straight frame (the replacement is straight) I would think the method described above (checking measurements v the FAM) is correct, no? Happy to be corrected if I have missed something. The measurements above do confirm what I see visually.

The smiley face was missing

To may variables

Condition of the cab mounts
Existing body shims
...link....

Not sure how the factory did it

Many thanks for the link. I will see how I get on, and post updates, once I get the old floor cut out.

One of your photos showed the ruler at the top of the hole, but all the hole dimensions should be to center. Not hard to find the center - just hold the ruler vertical and tangent to one side of the hole. Measuring to the top wouldn't matter unless the holes you're measuring to are different diameters.

Sorry but according to the FAM I have all measurements are from either the top or bottom of the hole but not the center. All of my measurements are to the top of the hole.

For the top hinge hole the top of the hole is 28.41" from top of frame, bottom of hole is 27.84" above frame. Therefore hole is .57" in diameter.

Image below shows the relevant page.

I didn't realize they measured to top or bottom of holes. Seems strange, but it works.

Ever other hole location I've ever seen was to center.

Thanks for pointing that out. I'm going to be setting up my cab for patch panel work soon and would have blindly used the center of the holes.

I was quite surprised too to be honest.

I have set up my frame to be level and am then using a laser level to ensure key points on the cab are where they are supposed to be (which as of now, they are not!). A prior poster had indicated that this would not work but I am pretty confused as to why not as the FAM clearly states vertical dimensions from a zero line (and the frame top) to each hole or point so for me the laser makes that vertical measurement easy. He seemed to say that getting those measurements correct is not going to help if gaps at the bottom were incorrect. i.e. get the gaps correct and not the measurements from the FAM? At least that was how I read it. Anyway, I will plod on and post updates here in the event it helps others.

Once I get the cab leveled out with the threaded rods I will post photos. New frame should be here in 2-3 days.