Indexing the driveline

[absintheisfun]

Anyone ever heard of indexing the drive line? My mechanic buddy told me it was important when you start making significant power. He said it was aligning the engine and transmission so that the angle on the drive shaft was at 00.00 on center....the factory had tolerances that would damage transmissions when the power output from the motor was too great.

Does this sound legit, or full of sh--??

[JEFFTATE]

What's the driveline in ?
Your '67 Camaro ?
If so , then yes , the driveshaft yokes should be indexed.
The yokes should be perfectly parallel to each other.( I corrected this , I originally said " perpendicular" instead of parallel. Sorry. I don't know what I was thinking. )
Have a driveshaft shop check them.

The factory tolerances are usually pretty good .
It needs to be done whether you are making a lot of power or not.
Even a stock car needs a correct driveshaft.

[zman1969]

yokes should be indexed.
The yokes should be perfectly perpendicular to each other.


Jeff I'm not sure what you mean by this "perpendicular" any chance you could show a picture of what you mean?
I've been into cars for 20+years and there still alot of stuff that I havent learned yet. I used to have a 69 z28 that a mysterious vibration that was noticeable 65 and up at 100 you couldnt see out of the rearview mirror- never could find it thats with different engines trans,driveshafts the only thing that didnt change was the rear end - no noticeable bent axles.... wonder maybe something like this had something to do with it.

[GetMore]

Not sure what your mechanic was talking about exactly, but if he was saying that you want the driveshaft to be perfectly in line with the engine and transmission (in both axes) then he is wrong.
You actually need a slight misalignment with u-joints, so the bearings move. If you don't allow for this movement they tend to wear out a lot faster. (It's a little counter-intuitive, but that's how it works.)

[zman1969]

I think hes meaning the joints have to be phased correctly on the drive shaft- IE its how the yokes are welded on it - not that there is a strait line from crank-trans-to pinion. I know GM uses a difference in pinion angle and ford usually offsets the diff to one side (hence different length axle shafts on Ford and equal on GM -so the u-joint rollers move and dont wear just one spot.
someone correct me if Im wrong.

[JEFFTATE]

[quote=zman1969;510980]Jeff I'm not sure what you mean by this "perpendicular" .

Sorry , I meant to say "parallel".
What I was referring to was the yokes that are welded onto the driveshaft tube itself. They are supposed to be parallel and even.
In other words , perfectly in line with each other.

A common method of checking for an out of balance driveshaft is to disconnect the shaft from the rearend and rotate the driveshaft 180 degrees on the rear end yoke and reconnect the driveshaft.
Then , drive the car and see if the vibration gets worse or better .
This can give you an idea of whether it's the shaft or something else.
A lot of old school mechanics call this method " indexing the driveshaft".

I think the original question of this thread was about getting the driveline angle correct.
Like , as in the pinion angle , and placement of the engine , transmission and rearend.
So that the driveline doesn't vibrate.