Is Frame level with Body?

[WB72]

I have a question about the differences / similarities of how the frame vs body lines line up to each other.

If I am setting up my suspention to make the truck sit level in its ride height with the body off, is the main portion of the frame sitting level with the ground, or is there a bit of rake to it compared to the body sitting level?

Does the frame sit as pictured? I do not have an unmolested truck suspension for me to check this out. Please help.

See picture for explanation.

[Steve Cole]

Subscribed. This would be good info for me too. I need to set my pinion angles. Thanks.

[WB72]

Maybe a bit more detail for an answer.

At ride height, is the frame level with the body line of the cab or truckbed? Like the first picture. RED LINE
or
is it skewed either higher at the front or rear compared to the body? like the second picture. PURPLE LINE

I'm basing my inquiry on the cab portion of the frame.

[Keith Seymore]

(In the absence of any other responses, I'll take a shot):

The straight section of the frame rails are parallel with the lower edge of the rocker, as you have shown in your first post. The line drawing is representative in that regard.

Now:

Do you have the engine installed? If you set the frame level now, how do you know it will still be level once you have installed the engine, cab and box?

Originally Posted by Steve Cole

Subscribed. This would be good info for me too. I need to set my pinion angles. Thanks.

The frame being level (or not) is not what determines pinion angle. What you are really interested in is the rear U joint "working angle", which is formed by the relationship between the pinion centerline and the drive shaft. You will need a completed vehicle, with engine/trans/driveline installed, and with the correct compression of the suspension to see where you are and make any corrections.

K

[Steve Cole]

Originally Posted by Keith Seymore

(In the absence of any other responses, I'll take a shot):

The straight section of the frame rails are parallel with the lower edge of the rocker, as you have shown in your first post. The line drawing is representative in that regard.

Now:

Do you have the engine installed? If you set the frame level now, how do you know it will still be level once you have installed the engine, cab and box?



The frame being level (or not) is not what determines pinion angle. What you are really interested in is the rear U joint "working angle", which is formed by the relationship between the pinion centerline and the drive shaft. You will need a completed vehicle, with engine/trans/driveline installed, and with the correct compression of the suspension to see where you are and make any corrections.

K

You are a wealth of knowledge Keith, I am glad you are a member here!!

I don't want to hijack the OP's thread so I will send you a PM with a follow up question. Thanks.

[Keith Seymore]

Thanks, guys.

Can you see the attachments in this link?

http://67-72chevytrucks.com/vboard/s...d.php?t=522180

They were previously Photophucketed but I can see them now.

K