Determining Driveline Angles

[The WidowMaker]

From what I understand, the angles @ each end of a 1pc d.shaft set-up should equal each other. I understand this as 3.0° @ the trans suggests I need 3.0° @ the rear end. Anyone want to confirm/correct this?

youre concerned about working angles (WA). the WA is a combination of both sides of the angle. so, if your ds was at 0* and your tranny at 2* you have a 2* WA. you want both of your WA's as close to 1* as possible, but not under (needle bearing issue you described). you also want both WA's no more than .5* different from each other. some will say 2-3* difference is ok, but like you said they help to cancel each other out.

if you really want it set up correct, dont fall into the camp that says "equal and opposite" when discussing the tranny and pinion. although that way will set it up correct 90%+ of the time it only takes a little time to measure your WA's and do it the best way possible.

[ScotI]

Originally Posted by The WidowMaker

youre concerned about working angles (WA). the WA is a combination of both sides of the angle. so, if your ds was at 0* and your tranny at 2* you have a 2* WA. you want both of your WA's as close to 1* as possible, but not under (needle bearing issue you described). you also want both WA's no more than .5* different from each other. some will say 2-3* difference is ok, but like you said they help to cancel each other out.
if you really want it set up correct, dont fall into the camp that says "equal and opposite" when discussing the tranny and pinion. although that way will set it up correct 90%+ of the time it only takes a little time to measure your WA's and do it the best way possible.

It seems spacial concerns will hamper many targeting this 'ideal' range. What is the 'failure' if working angles cannot achieve that target range (as close to 1° as possible)? To ensure I understand this 100%, you add the sides together to yield the WA correct or how does it work (ex: trans output + d.shaft angle = 'front' WA; d.shaft + pinion angle = 'rear' WA)?

*EDIT* I did some additional reading of some GM tech-specs @ lunch & it stated: To calculate the working angle of each intersection subtract the smaller number from the larger to obtain the working angle.

So my set-up would yield 2.6° WA @ the trans & 2.9° WA @ the pinion. These are within the .5° range to be optimum. The spec sheet also indicates up to 4° is acceptable but not to exceed the range. It would seem I can leave things as is, or use a dbl CV style joint @ the trans & remove the pinion shim to put me closer to @ 2° down.

[The WidowMaker]

it depends on how you measure and if you have positive and negative numbers, but your method of subtraction is correct. i usually zero my digital on the ds and then there is no adding or subtracting needed. i just have to rezero every time an adjustment is made, but its a 2 second process.

what was 0*? i ask because if your trans was pointed down in the back, and your driveshaft was climbing up towards the pinion, then you have a 6.6* WA.

Tim

[ScotI]

Originally Posted by The WidowMaker

it depends on how you measure and if you have positive and negative numbers, but your method of subtraction is correct. i usually zero my digital on the ds and then there is no adding or subtracting needed. i just have to rezero every time an adjustment is made, but its a 2 second process.

what was 0*? i ask because if your trans was pointed down in the back, and your driveshaft was climbing up towards the pinion, then you have a 6.6* WA.Tim

The trans is pointed down, the d.shaft climbs up toward the pinion, & the pinion is now pointed down.

[Vegas69]

With a driveshaft sloping UP towards the rear, you add the working angles. A driveshaft that slopes up is no bueno...

[ScotI]

Originally Posted by Vegas69

With a driveshaft sloping UP towards the rear, you add the working angles. A driveshaft that slopes up is no bueno...

How is it different vs. a d.shaft sloping down?

[Vegas69]

Your driveshaft and driveline/pinion are on different planes with a driveshaft sloping up. Compare it to bending your arm at your elbow.

With a driveshaft sloping down, it's on the same plane as the pinion and driveline.

For instance:

Driveline angle/Pinion Angle of 4.2 degrees
Driveshaft slopes up 1.6 degrees
Your current front working angle is 5.8 degrees
Exaggerated example /\

Ideal:
Driveline/pinion at 3 degrees
Driveshaft slopes down 1 degrees
Your working angle is 2 degrees
//

With a working angle of 5.8, you are in jacked up 4x4 territory. I doubt the car will be happy at high speed. All my research calls for less than 3 degrees of working angle for high speed. 1-2 degrees is really ideal. You will need to chop your tunnel or compromise on working angles by running non conventional angles.