two piece drive shaft questions

[dotcentral]

I was going to replace my carrier bearing and ran into the same trouble as just about everyone else thats tried it. My front driveshaft was already disconnected at the tail housing as I had pulled the engine. Anyhow, went to reinstall the carrier bearing and front drive shaft and discovered I need a new U joint, the needle bearings were falling out. I found them all and put it all back together. Pretty sure I got the two driveshafts phased wrong. I need to get a new U-joint anyway, so I'll try to do the U-joint and realign the driveshaft all at once.

My question, I think I'm 90 degrees off on the driveshafts right now. Other than running the truck, stopping, crawling under, redoing the driveshaft 1 spline at the time, until it runs right, is there a better way to get these things lined up right without all this trial & error?

I know better care should have been taken when we pulled it. I had too many people when we put the engine back in (dropped the trans at that time & attached to the back of the engine). Unfortunately, I haven't been able to get anyone to come over since then to help me finish it all up.

[flyboy2610]

I hadn't really considered this issue regarding my upcoming engine pull/tranny swap.
I too would be interested in knowing how to 're-phase' a driveshaft.

[Mohillbilly]

I replaced the carrier bearing on my 64, and dropped the shaft in my 70 several times while doing the clutch. I never had any problems, and paid no attention to how the two shafts went back together. Maybe I was just real lucky.

[wt4speed#2]

To the best of my knowledge if you line the grease zerts up this should do the trick , when you replace the front joint install it the same position as the old one comes out , time it with the zert on the rear and it should be fine. Short of taking it all out lock stock and barrel and having it balanced

[dotcentral]

Jamie, I've been told by a couple of people that each half of the shaft is matched up to the other. Basically, that the shaft is balanced as an assembly, and that if you don't put them back the way they came apart you could get driveline vibration.

I don't know if its true, just what I've been told. I've found out lots of things well meaning people have told me were not true, so take it as hearsy.

If you got a grease pencil or some light color paint, it might be a good idea to put a line on them to mark how they were at the beginning, to avoid this issue. I used a dab of grease on mine, but that wipes off pretty easy. I think I'm about 90 off on mine, but I'll look underneath at how the zerks fittings line up, maybe thats the trick.

[FORDification]

Driveshaft phasing is most definitely not a wive's tale....though it's not as critical on our trucks with two short shafts as it is on larger trucks with more U-joints and longer driveshafts, but it's still something you need to be aware of when disassembling/reassembling your setup.

Your driveshafts will be phased properly when one U-joint is positioned so that there's a top, left, right, and bottom cap, the other one in an identical position. Both yokes need to be be in the same plane. If the second U-joint is installed out of phase, like maybe pointing out at a 45-degree angle when compared to the first, it'll often cause a vibration that's hard to track down and could also cause some binding in the driveline.

[dotcentral]

Keith, I took a look under mine today. If I'm off, its 90 degrees off, not 45 or some other . Unless it can be 180 degrees off.

wt4speed#2, I only notice 1 zerk fitting on my entire driveshaft assembly, its behind the carrier bearing, on the front end of the back half of the 2-piece drive shaft. (That's a lot to have to say) Mine's a f100, maybe the heavier GVR trucks have a different arrangement. I might not be seeing all of them, tried to feel around where I could see, but couldn't find anything else trying it that way.

[68F250]

From the '68 shop manual.

[Mohillbilly]

Ignorance is bliss. Now I have to get my lazy butt and fat belly under there to check things out. I'm glad this topic came up. Ya learn something here every day!

[NM5K]

Yep. Being they need to be in the same plane,
you have two options as far as the right setup.
Being there are only two ways for it to go, first
try one, and if it vibrates , run it around 180
degrees, and try that. One of the two should be
smooth. If not, something is outa whack, and the
shaft needs a balance, or bad u joints, etc...
I had a vibration on mine that I thought was probably
a shaft out of balance. I changed the two rear u joints
first, and it still did it. The front u joint behind the tranny
*felt* tight, etc, but I ended up changing it anyway...
Viola! it was that joint...It's been pretty smooth since,
except lately I've been getting more of a clank with
rough shifting, real slow driving at near idle, etc...
Either I've got one of the new U joints flaking out,
or my rear end is getting a bit of extra slop...MK

[wt4speed#2]

1972sportcustom

Each u-joint should have 1 as well if not how you gonna lube them,
Tony B

[dotcentral]

68F250, thanks for the diagram. I'll have to print that out & crawl back under there again and see how I've got it lined up.

[wt4speed#2]

There should be one on each u-jointhow elese could you lube them

TonyB

[NM5K]

I wouldn't go by the zerk fittings, although that well
could pan out ok...I'd go by the position of the yokes.
Thats the critical part. They should be in the same plane.
It's probably possible to have the shaft correct as far as
balance, yet have the zerks on opposite sides, if they
had ever been changed out. Also, make sure the
U joints are centered in their mounts. That was the
main problem on mine...Whoever installed that one
the last time, didn't properly center it, and it threw it
out of balance. MK