BrianCunningham

Thought this section may like to see this

http://www.macsmotorcitygarage.com/2...e-and-phasing/

VikingTrad3r

Im just putting my driveshaft back in my 85, with the extension housing. thank you. i marked my rear connection to the ujoint but never understood why i had to do it. thank you for posting. VikingTrad3r

Crepitus

Nice looking car Viking! There is a hand full of guys on here that know their stuff. When they talk I listen. Brian is one of them.

frankinvett84

I had no idea how important phasing was, I have had other vehicles that had some drive train wobble issues now I wonder. My question now is, if out of "phase" how would you go about getting it back? After looking at the end of the video where they show "in phase" the universals don't appear to be lined up or tuned 180 deg. Just wondering

DanielRicany

My auto tech instructor spoke of this. He referred to them as "cancelation angles".

BrianCunningham

Some driveshafts have a splitspline
let's you put them together out of phase
our parts area all fixed,

rocco16

This ^. One-piece driveshafts and halfshafts cannot be installed out-of-phase.

Tom400CFI

Still don't need to mark it. The phasing that they're talking about would only be affected if you cut the yoke off the drive shaft, and welded it or a new one back on in a different orientation. They simulated that in the vid by having a yoke that was not welded on that shaft, and held by a threaded retainer. They loosened that retainer and moved the yoke on the shaft -something that is impossible for you or I to do w/o cutting/welding of the shaft and yokes.

In short, changing U-joints doesn't change the joint phasing in a drive shaft.

BrianCunningham

You still need to put them back in the same orientation

If they see a lot of stress, they can snap if the orientation is reversed

bjankuski

I agree

arbee

Question: Does the driveshaft have to go back the way it came out, or 180 degrees make no difference. Just wondering if balance enters into this.

VikingTrad3r

I have same question as arbee.

plus:

1. if you slightly lowered the tranny and engine using a jack (to say, swap a tranny dipstick tube grommet) how do you know exactly what the right "level" to return the tranny/engine to? The c-beam technically sandwiches it all and should hold it mote or less level but if we are out a half inch does this cause problem? Is the answer that you know its level when you can light the cbeam bolts up and get them through the tailhousing and rear diff?


2. Also, you should mark the rear pinion nut when you remove the rear u joint coupler thingy right? i marked where it was, then when i replaced the pinion seal i kept yoinking until it was lingned up. too serious torque to get it lined up.

BrianCunningham

shouldn't

BrianCunningham

sounds like you did it right

Tom400CFI

cardo0

Wow phasing the driveshaft. Never knew of it. I always knew how important getting the input and output parallel is. I wonder how many driveline shops know 'bout phasing?

Tom400CFI

All of them. This info is not new, and no secret. It's just not talked about here much, b/c how many folks are welding yokes to tubing to make drive shafts?

cardo0

Just a note to share here, i see the newer monster trucks are using chain to transfer output to the lower chassis to all the wheels. Not to long ago the monster trucks had huge d/s angles. I got to a pinion light up white hot during a night event. Last trucks i saw used like 6' of chain from the trans output down to the transfer case that sits nearly wheel centerline level.

93Rubie

Nothing new here at least to me. Another reason GM went from halfshafts to CV shafts. Constant velocity at ALL operating angles on the C5 and up.