phasing two piece shaft

[Fast68Chevy]

someone who knows about drivelines please explain how to properly phase and install a 4 speed(truck only) two piece driveshaft,

how all three U joints caps are supposed to be in relation to each other(aligned perfectly or not) and how to know which splines to engage in the center slip deal at the carrier bearing, i worded that as best as I can



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Randy- Lincoln, IL

r68c30@hotmail.com 2177353230
-71 C-10 350/CH465/3.07, assemble it, yeah right, that'll happen in this world,(not)
-84 Z28 Camaro 5.0L 700R4, 3.73, beater, paid way too much for it like an idiot,,
-84 Firebird SE 2.8L T-5, rod knocking, dammit,,
-82 Firebird 350 4bolt (TBL)/TH350, not running, dammit...
buy/sell/hoard/trade most any GM vehicle parts of any kind
-parting out: '81 Cutlass Supreme Brougham
*Paint is overrated
© RSS Enterprises 2000

[Fast68Chevy]

ok how about when sliding the two shaft halves back together?(front and rear shafts)

how do i know when ive got them slid together right ? i dont want to have unbalance problems

thanks

[COBALT]

Well, this may be a dumb question but are you getting it out of an existing truck, or are you putting together a two-piece driveline out of spare parts?

If it's comming out of a truck just mark the yokes with some chalk. The U-joints simply go in as they normally would (don't forget to tighten that nut on the removable yoke in front of the support bearing). The only special U-joint is the rear one, which for me was bigger and more expensive (the U-bolts alone were $5 a piece!).

If it's made out of spare parts then you'll have to have it balanced, or simply get it balanced by trial and error. I marked my yokes up before I pulled the driveline, and realized that the removable yoke in front of the center support bearing was oriented the same as the opposite yoke on the same shaft, but not perfect (like 1 spline off). Since the end of the shaft is splined for the removable yoke I just oriented it so the chalk lines matched. If you don't have chalk lines then try orienting the removable yoke so that it matches the other end (not perpendicular but as parrallel as possible).

When putting in the middle U-joint you'll just have to guess on how the front shaft should be oriented. If there's shaft weights on both shafts try to orient the shafts to the weights are on opposite sides...

good luck.

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'69 3/4 ton C20 2wd w/ 350ci/400THM and a wood bed!
'69 3/4 ton Custom 20 2wd w/ ORIGINAL 350ci/4sp Manual and a wood bed (parts beast).
Seattle, WA.

*See pics of my trucks and project at www.webshots.com!

[71GMC_3/4T]

I found the info in my chassis service manual. I wrote down the page number in the back, but the book is at home and I ain't. If you have the book, it shouldn't be too hard to find. If you don't, let me know and I'll scan and send it to you.

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1971 GMC 402/TH400
Workin' on it!
Gettin' on it!
Lafayette, CO
**Looking for a nice fleetside longbed for my GMC.

[tom hand]

If it is an original driveshaft you should be able to look in female part of the slip yolk and there should be one spline that is cut double wide, on the male part there should be two splines that pinged together where they will only fit in the double wide part. If the two parts where originaly together it should still be balanced because it will only fit together one way. Hope this helps.

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72 GMC Sierra SWB almost finished---- 84 Softail
Olive Branch MS

[71GMC_3/4T]

I checked the book last night. You phase the rear driveshaft 4 splines to the left of the front one, starting with the u-joints lined up as a reference zero point before you rotate it the 4 splines. I think this was for everything except the 305, which is only 2 splines to the left.

[Scrub]

Sometimes if you clean them up you can find an arrow stamped into each one, but that is ussually only if they have been worked on. I never heard of this 4 splines to the left stuff. All the shafts I ever had built and balanced where lined up joint to joint flat and they were marked.

Good luck

[texnician01]

for that shaft the two ends of each driveshaft should be in the same plane NOT 90 degrees off. so you want the slip yolk to go on so that the saddles on each end of the shaft are horizontal. and then the rear shaft should be both vertical.

the slip yolk is not usually not keyed on those driveshafts so it will go on in any direction.

if you need a better explanation let me know. I may even be able to get pics of mine.

hope this helps

Nathan

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1969 C-10 292 I-6 4 spd in the middle of a restoration. going to get a 327 and 3.07 gears but keeping all of the original parts so I can put it back to original later on down the road.
55 chevy 4 door 150
47 Willys CJ-2A

[COBALT]

Yeah, texnician01 and I basically said the same thing. At least for my year the slip yoke could actually go on the splines in any orientation (there isn't one cut double-wide into the female part like tom hand had suggested).

Therefore I made an "educated guess" and put it on in the same plane as the yoke on the other end of the shaft. Turns out there was only one position where this was even possible, so I assumed that had to be right.

I think balancing the second shaft to the first may be a pain. Like I said before if there's weights on the shafts then I'd orient them to be opposite each other (not on the same side) as your first try. More than likely they'll be 90 degrees to each other, which may be a pain to experiment with. You may have to keep pulling the driveline, pressing out the center U-joint, changing the orientation, and pressing the U-joint back in. Takes a while...be carefull with the needle bearings on that center U-joint. Tapping it in and out a bunch can damage them...

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'69 3/4 ton C20 2wd w/ 350ci/400THM and a wood bed!
'69 3/4 ton Custom 20 2wd w/ ORIGINAL 350ci/4sp Manual and a wood bed (parts beast).
Seattle, WA.

*See pics of my trucks and project at www.webshots.com!

[71GMC_3/4T]

I was just passing along what the good book said.
Hopefully this has something to do with driveline vibe since I pulled mine apart to change the u-joint and forgot to mark it (thought it would only go back one way!) and put it together at random.
The truck shakes like a dog sh!ttin' razor blades above 75 or 80, so I don't go that fast. I hoped some day when I got the time that re-timing it like the book shows would help to cure this problem.

[Fast68Chevy]

ive seen service manuals that say that about the 4 splines back deal, i think says it in the chilton's, i have a 71 chassis overhaul manual here i will dig through and see if has any of this info in it or not, and look in the chiltons again too.

i stil have no idea how its supposed to go, the driveshaft is out of another truck and the two halves were pulled apart(at the spliend slip joint) and so I have no idea, i had the carrier bearing replaced today at napa shop and i am replacing the tranny yoke U joint and thats it, the rest is good enough with some new chassis grease

thanks guys

[tom hand]

OK well the two piece drive shaft in my 72 is keyed where it will only go together one way,but if yours is not it is still easy to figure out. All the u-joints should be in the same plane,lay it on the floor and when they all lay flat you got it. Put it in the truck and if it vibrates,just change one half 180 degrees. there are only two ways it can go together.

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72 GMC Sierra SWB almost finished---- 84 Softail
Olive Branch MS

[Fast68Chevy]

ok, how about someone here with a 4 speed longbed truck with original setup under it(that doesnt vibrate at all) go and look under and see if the wieghts on both halves are on same side or are 180 from each other, and see f the U joint caps are all inline

anyone ? thanks if so, this would be good to know/find out

[69 longhorn]

You got a 50/50 bet there.....says the gambler,pretty good odds. If it shakes , pull it ,& flip it 180.........69

[Fast68Chevy]

heh, true, here goes nothing then

[boilrman]

If I remember right my Haynes manual says there is no phasing unless you are dealing with a 4 wheel drive.

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1971 Chevy 1/2t, 350 -- SOLD
1998 Yamaha V-Star 650
1970 Chevy 3/4t, I6(freshly rebuilt), 4 speed
Keokuk,IA

http://communities.msn.com/SchweringFamily/shoebox.msnw

MSN Messenger = boilrman
Find a job you love and you'll never have to work a day in your life.

[texnician01]

OK.. this is texnician01's dad speaking. However, we both agree.. the wieghts that are on the driveshafts are for balancing the individual shaft only... and have nothing to do with balancing the two shafts together. When a simple u-joint rotates through an angle there is a speed up and slow down phase that happens twice as the shaft makes one rotation. This motion is transmitted through the shaft to the rearend. The sharper the angle the worst the speed up /slowdown cycle. With cv joints the shaft is made up of two joints that divide the angle. Their cycles are designed to be 90 out of phase, thus they cancel each other out, as one is speeding up the other is slowing down. When puting the slip joint together each end of the shaft must be the same..horizontal for example.. so that they can bend in the same plane..this is a must. Because of the way the slip joint is made, this will make the rear shaft 90 out of phase with the front shaft, thus..the two help to cancel out the speed up /slow down cycle.. which equals = smooth transmission of power.. no vibration... no twisting torquing of shafts and u joints.. believe me .. it works. we may be able to get pictures of our WORKING 4 spd driveline for you this afternoon.

Rich & Nathan

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1969 C-10 292 I-6 4 spd in the middle of a restoration. going to get a 327 and 3.07 gears but keeping all of the original parts so I can put it back to original later on down the road.
55 chevy 4 door 150
47 Willys CJ-2A

[COBALT]

Very cool. I bow to thee. LOL

Looks like I got lucky with the weights on my shafts then. I figured they were there to balance both shafts together, so I figured I'd orient them opposite each other...

My driveline is as smooth as silk. Even at high RPMs. Chevy gods must be smiling on me...

------------------
'69 3/4 ton C20 2wd w/ 350ci/400THM and a wood bed!
'69 3/4 ton Custom 20 2wd w/ ORIGINAL 350ci/4sp Manual and a wood bed (parts beast).
Seattle, WA.

*See pics of my trucks and project at www.webshots.com!

[Fast68Chevy]

i found arrow on my rear prop shaft(4 speed drive shaft with splined coupler roughly in middle near carrier bearing- 3-speed manual and auto trans driveshafts are a different animal altogether) today, but cant find one on the front half(half with the carrier bearing and male splined end), did find an indented dot on one of the splines on that end though, so hmmm.... maybe those are the splines mate together.
does anyoen know if the rubber splines seal in the middle spline coupler deal are available new still ? it is inside the cap that unscrews off the front end of the rear prop shaft

the way that the arrow and the dot go together makes all the U joint caps line up same from end to end of shaft

so hmm.. so far so good i think as long as I can un jam the prop shafts fro each otehr at the splined coupler,........ crap...

good info guys!


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Randy- Lincoln, IL

r68c30@hotmail.com 2177353230
-71 C-10 350/CH465/3.07, assemble it, yeah right, that'll happen in this world,(not)
-84 Z28 Camaro 5.0L 700R4, 3.73, beater, paid way too much for it like an idiot,,
-84 Firebird SE 2.8L T-5, rod knocking, dammit,,
-82 Firebird 350 4bolt (TBL)/TH350, not running, dammit...
buy/sell/hoard/trade most any GM vehicle parts of any kind
-parting out: '81 Cutlass Supreme Brougham
*Paint is overrated
© RSS Enterprises 2000



[This message has been edited by Fast68Chevy (edited April 27, 2002).]