Where to measure for drive line angle??

[pete57]

Wheres the correct place to check my engine/driveline angle. '64 c10 with 5.3, im getting about 10 degrees with my angle finder on top of intake and on the trans yoke, but getting about 3 degrees on bottom of trans pan 4l60e. Which one would be the correct place to check from?? Thanks..

[toddoky]

Take the engine crank angle off of the balancer or the machined top surface of the block if the manifold/valley cover is removed. If you want to take the inclination angle off of the transmission, you can't use the pan of the 4l60 as it's not parallel to the input/output shaft centerline, so you need to use the yoke U-joint caps or the machined output shaft seal surface of the extension housing if the driveshaft is removed.

[pete57]

Thanks, just what i was lookin for. Manifold is not removed so ill go off the other 2 locations. Should my angle be around 3 degrees at both the balancer and trans yolk?

[toddoky]

Originally Posted by pete57

Thanks, just what i was lookin for. Manifold is not removed so ill go off the other 2 locations. Should my angle be around 3 degrees at both the balancer and trans yolk?

The actual engine/trans inclination angle is a reference value only and is only important in how it relates to obtaining optimized U-joint working angles.

You need to take three angular measurements in order to correctly calculate the U-joint working angles, which are the eng/trans inclination angle, the driveshaft angle and the rear end pinion angle with your truck chassis/suspension resting at its intended static ride height.

Once you have those three angles you can calculate the U-joint angles through basic subtraction or addition of the angles from one another based on their up/down disposition of each angle. If the eng/trans points down to the rear and the drive shaft also slopes down to the rear then you would take the engine/trans and driveshaft angles and subtract the lower of the two from the higher of the two to determine the front U-joint working angle.

The rear U-joint angle would be calculated the same way as long as the driveshaft and rear pinion both sloped down towards the rear of the truck (both downslope angles). If your driveshaft sloped down to the rear of the truck (down angle) and your pinion was tipped down towards the front of the truck (up angle) then you would add the driveshaft and pinion angles together to calculate the U-joint working angles instead of using subtraction.

Your goal should be to achieve U-joint working angles the are the same within 1/2 a degree and be a minimum of 1/2 a degree and no more than 3 degrees.