Driveline In-Line

[rbsWELDER]

In planning my build: SBC, 700R4 and Jag Rear end, I was always under the impression (naïve) that the mounting points on the frame pulled the driveline into alignment. After reading the last couple of threads, I realize that I was making a faulty assumption (Don't say it, I know what they say....).

Could someone point me through a tutorial on driveline alignment or give me the short version here?

Thanks in advance!

Mark

 

[fluidfloyd]

Mark,

When installing any IRS unit you should always center it measuring to the wheel hubs or better yet to the inboard a-arm pivot points. (This only applies to pivot shafts that are parallel to each other and the chassis center line.) In most all cases you will end up with the pinion gear center line being offset by some small amount, Usually they are only 1/2 to 7/8 of an inch but this is not a problem. You just threat this alignment the same as you would treat the side view or vertical alignment. Align the engine crankshaft dead nuts on the chassis center line. The drive shaft will now have a very slight offset and that is what you want. This is called phasing the U-joints. The same goes for the vertical alignment. If the engine crankshaft is dead level the the pinion should be like wise. You do want a height difference between the engine and the IRS. You need some angle in those u-joints. Now you are phased in the vertical layout. The one exception that I can think of is quick change IRS units. We use a lot of the Winters IRS setups and their pinion is on the housing case center line and the wheel center line. It that case you will have a driveshaft that will be on the chassis center line. As for angles for drive lines:

http://spicerparts.com/anglemaster/measuring-angles

http://www.customdriveshafts.com/

Hope this will help you. Good luck.

George

 

[Screaming Metal]

What George said! In a American car, the motor/trans cl and the driveshaft to the rear ought from a fairly straight line. Now thats not taking into account the motor and trans moving around and the rear axle moving up and down....Now that Jag rear doesn't move (the mounts can let it jiggle some), but the axles articulate....
Once you get that Jag rear setup right, you won't have a minutes trouble with it. Set it up out, and you'll be fighting it the whole way....