Cobrakev

Great, me not being a Math Geek, makes this all confusing without pictures........

CrazyAl

No, this is where the error is coming from. If by "your measurements" the numbers are +1 driveshaft and +2 pinion, then "my" measurements would instead be +1 and -2 respectively, becasue whereas you are taking the two measurements with different sign conventions, I am taking them both with the same sign convention. Thus, where you would add 1 + 2 and get 3, I would do 1 - (-2) and also get 3.

The two techniques both yield the same results...you just have to get the measurement convention matched to the formula.



Not really. The formal definition of an angle is the difference in angles between two given lines and a fixed referance point. "difference" means "subtraction". Remember back in grade school? Keep in mind that this is exactly how the tools are made. An angle gage measures angles with respect to a vertical plumb line...a single common referance point.



You are making the same mistake that I pointed out earlier in this post. With "my method" of subtraction, you must take all your measurements with the same referance (just like how the tools are made). I worked this same example out on paper...see the attachment. Both methods get the same results.


I have no problem with the measurement method you are suggesting, now that I know that it also follows a particular measurement method. "Your" technique works fine, but it's critical that you also mention the peculiar sign convention for how the angles are measured. I object to that method becasue the sign convention doesn't follow the way the tools work or the way the math should be done.



[IMG]local://upfiles/32957/E4A61290DB004C5EBDB61C0CA1DA775E.jpg[/IMG]

07GT

On your paper you come out with the same number I came out with, and yet you say, in your first post that +3 + (+1) = 2, or as you would say +3 - (-1) = 2, explain that. Again call anyone, anyone, in the suspension business and explain your theory and see what they say. Let me know what they say when you say +3 + (+1) = 2. You object to the way pinion angle is measured because it doesn't follow your engineering protocol, well I'm sorry, in the real world, this is how it is. You don't have any problems with the measurement method I am suggesting? Are you saying I'm wrong or right? The fact that the sign convention is not mentioned, I can see is a problem, but you have to explain things in a manner that everyone in the industry will understand, to try and change that convention now only adds to the confusion. I know you understand this, and I know you know I do. My point is that we should all speak the same language, which is as I have explained. How about a beer? [sm=icon_cheers.gif]

CrazyAl

In my first post I did indeed say 3 and 1 degrees would equate to two...becasue I did not know you were assuming an unusual sign convention. You didn't state in your post how those angles were measured. I assumed they were measured in the formally correct method, which lead to my misunderstanding. When you clarified (later in the thread)that you wereusing a nonstandard sign conventionit all became clear, and you were indeed correct...IF you mention how the angles are being measured.

3 and 1 does indeed equal 4 with your measurement method.
3 and 1 equals 2 with the typical measurement scheme.

In my post I said that 3 and 1 equated to 2 becasue I didn't know you were using a nonstandard sign convention.

I have been involved in motorsports for many years, and "my method", which was taught in an SAE mechanic's course, is the only method that I have ever seen used. All the race shops and mechanicsI know do it this way. Why? becasue that is how the tools work. When you stick your angle gage on the driveshaft or the pinion flange, it reads angles one way only. It doesn't suddenly reverse signs when you put it on the pinion.

Again, "your" method works fine...but it's not clear unless you state how those angles are measured. I was confused becasue you didn't state the angle measurement protocol in your original post.

It's a bit like saying "The 2007 GT comes with a 6-speed"....well to most people it doesn't. But if you count reverse.....

Stoenr

You guys just killed what brain cells I had left!

FREAKO

I thought the easiest way was to make sure you pinion flange and the flange on the tranny were parallel with each other? I would think with a 1 piece driveshaft, with your pinion set parallel to your tranny flange would make the pinion actually above 0...showing positive angle. I measured my tranny flange and its at 86.7 degrees (measuring on the passenger side of the flange with the readout towards the driver side) and the pinion flange was at 86.7 degrees (measuring on the drivers side of the flange with the readout towards the passenger side.....Im using a Smart Tool digital angle protractor.....this is with the car on jackstands.....weight of the car on its rearend (suspension compressed). I think it doesnt matter if the car is on the ground or jacked up...just as long as the suspension is not hanging.....the 2 angles should move in parallel as your jacking it up under the rearend........my 2 cents.

CrazyAl

That is correct for a 1-pc driveshaft. However, that is NOT correct for the oem 2pc shaft.