Alignment of driveshaft yokes & mystery vibrations (1 Viewer)

[lostmarbles]

I must give credit to "Australian 4WD Action" magazine and "Roothy" (the magazine's key contributor) for finally getting me to look under my cruiser and check my driveshafts for their "yoke alignments".

My back shaft is easy to photograph and it conforms to what the magazine refers to as "having the yokes in the same plane".

(I've drawn a cross on each yoke so you can see clearly that they are indeed in alignment.)



Now, to my astonishment my front drive shaft is set up exactly the opposite. Its yokes are 90 degrees out of alignment!

I'd show you a photo but my crossmember gets in the way of photographing it.

My question is - Should I alter the front to match the rear (where the yokes are aligned)?

According to "4WD Action", unless they are aligned correctly - the shafts will cause vibration problems. Yet I haven't noticed ANY vibration issues with my front driveshaft!

Any words of wisdom would be much appreciated.

 

[spotcruiser]

You probably haven't gone fast enough or on smooth roads in 4 wheel drive, where you'd notice it. You won't feel driveline vibrations at 5 mph or on a washboard.

You should phase them properly, because that is the way they should be. If being out of phase can cause vibrations, you have to assume that it can also cause increased wear. Phasing them properly only requires you to disconnect one end, pull the two halves apart, put the two halves back together in-phase, and reconnect.

 

[lostmarbles]

You probably haven't gone fast enough, or on smooth roads, in 4 wheel.

Ha Ha -----Yeah.

I think I really know the answer to my question - Which is that there is no doubt that I should align the yokes on my front shaft to match the way they are on my rear. Thanks for confirming this.

 

[spotcruiser]

By the way, there is a diagram showing correct orientation in the FSM.

 

[lostmarbles]

By the way, there is a diagram showing correct orientation in the FSM.

You're right of course. - I just looked it up and here it is. (Pity they never stressed the importance of having the yokes orientated correctly though.)



Cheers

PS. Chapter 5 in my FSM is devoted entirely to the propeller shafts and nowhere in it can I see a clear statement about keeping the yokes in alignment when reassembling the splined/sliding joints. Instead it simply advises putting match-marks on components before dissassembly. ------ Not really good enough considering driveshafts often "fall apart" at the splined/sliding joint by accident when someone has removed the shaft and had no intention of separating the halves. I suspect this is why my front is misaligned. I recently removed it for painting and I vaguely remember the halves separating during that work!

 

[spotcruiser]

Yep, they could have put additional emphasis on it.

This is a scan of the photo in a mid-70s manual (US market, at least). It is not a very clear photo, but it does show the zerks facing out on the same side and it mentions the mating marks which can be very difficult to find.

HTH.

 

[andrewfarmer]

My back shaft is easy to photograph and it conforms to what the magazine refers to as "having the yokes in the same plane".

(I've drawn a cross on each yoke so you can see clearly that they are indeed in alignment.)

View attachment 229793

Any words of wisdom would be much appreciated.

Actually it's not aligned correctly. You'll see from the pic the yokes are not in line properly. Remove the sliding yoke and turn it (almost - the splines are not symetrical on the slider) 180 degrees and they'll be properly in line...

 

[lostmarbles]

Actually it's not aligned correctly. You'll see from the pic the yokes are not in line properly. Remove the sliding yoke and turn it (almost - the splines are not symetrical on the slider) 180 degrees and they'll be properly in line...

You've lost me Andrew

I would have thought that turning one end of my rear driveshaft 180 degrees (in relation to the other end of it) would still have the yokes aligned - but the grease nipples would just end up 180 degrees out-of-alignment (making it an extra hassle to grease that driveshaft).

(At the moment I can move the drive shaft into a position where I can reach all 3 ZERKS - sorry - must remember ZERKS not NIPPLES...... at the same time without having to roll the vehicle further.)

What am I missing? Or is your smilie supposed to have one eye blinking?

 

[andrewfarmer]

You've lost me Andrew

I would have thought that turning one end of my rear driveshaft 180 degrees (in relation to the other end of it) would still have the yokes aligned - but the grease nipples would just end up 180 degrees out-of-alignment (making it an extra hassle to grease that driveshaft).

(At the moment I can move the drive shaft into a position where I can reach all 3 ZERKS - sorry - must remember ZERKS not NIPPLES...... at the same time without having to roll the vehicle further.)

What am I missing? Or is your smilie supposed to have one eye blinking?

The splines are set up such that you cannot turn it exactly 180 degrees. I expect you'll find it turns to a position that lines the yokes up perfectly.

And hey, you can play with zerks, I'll stick to nipples!

 

[Coolerman]

Funny, that pic doesn't show the arrow stamped into the shaft you can use for alignment.

 

[supermanrs]

Not trying to hijack, but I figured this falls in the spirit of the thread, but how far out of perfect alignment would cause a vibration. 1 tooth? 30 degrees? 90 degrees?

 

[lostmarbles]

The splines are set up such that you cannot turn it exactly 180 degrees. I expect you'll find it turns to a position that lines the yokes up perfectly....

Not trying to hijack, but I figured this falls in the spirit of the thread, but how far out of perfect alignment would cause a vibration. 1 tooth? 30 degrees? 90 degrees?

I'm doing a multiquote here because I think these two statements/questions are directly connected.

I thought more about what you said after reading it last night Andrew and I now see what you were on about. You figure (and I agree) that my photo makes it look like the alignment is "a bit less than 1-spline-out-of-alignment". And you think that if I turned one end approx 180 degrees in relation to the other end - I would achieve "perfect alignment". (Because you're saying the spline machining was done in such a way that "perfect yoke alignment" is only achievable when the splines mate together in ONE relative position - as opposed being able to be perfectly aligned in TWO positions that are 180 degrees apart.)

Well I'm happy to tell you that you are WRONG WRONG WRONG!!! And this zerk-alignment image from the manual proves it:



If I followed your suggestion - one zerk would be almost 180 degrees out-of-line with the other two. And before you shout that my zerks/universal-joints are installed incorrectly - I must inform you that they are exactly ex-factory (having NEVER had any universal joints replaced).

(Jeez Mate. It's nice to be able to talk straight with another kiwi. I'm often scared of offending some of those foreigners out there!)

And I think a minor misalignment (like what is apparent in my photo of my rear driveshaft) - if it exists - couldn't possibly cause any problems.

It's wet and cold outside now. But I may just take another photo to clarify the alignment if I can. (But I'm certainly not going to fix the front shaft today.)


PS. It would be interesting to try and find those arrows on mine Coolerman. (When I remove the rear for painting I'll look for them.)

 

[lostmarbles]

How's this photo Andrew. I tied a piece of string on the driveshaft this time. (It just goes to show how much a camera can lie.) Hell - I tried to run a line between the yokes in the first photo (using the "draw feature" in Microsoft Paint) but the line had to be "bent" in order to connect the two.

Here's the new "better" photo. Now the yokes look perfectly aligned don't they?:



And I'll have to be more careful what I say. I'm presently "in deep water" in another thread. And calling people "foreigners" may well offend them. (I used that word "tongue in cheek" -and whilst bearing in mind the fact that most people on MUD would regard me and you as "foreigners".)

 

[cruiserbrett]

How's this photo Andrew. I tied a piece of string on the driveshaft this time. (It just goes to show how much a camera can lie.) Hell - I tried to run a line between the yokes in the first photo (using the "draw feature" in Microsoft Paint) but the line had to be "bent" in order to connect the two.

the FSM and conventional wisdom call for the zerks to be aligned not parallel, but rather so that the rotational torque of the driveshaft puts the zerks in a compression load. Imagine the twisting of the yokes from transfercase to axle. for this example imagine the driveshaft rotated clockwise when propelling the truck forward when view from the rear: If you had the transfer case flange yoke at 12 and 6 oclock, and the first driveshaft yoke at 3 and 9pm, you would want the zerk at the 1:30 or 7:30 postition. For the rear u-joint, you would want it at the 4:30 or the 10:30 position. Make sense?

 

[lostmarbles]

the FSM and conventional wisdom call for the zerks to be aligned not parallel, but rather so that the rotational torque of the driveshaft puts the zerks in a compression load. Imagine the twisting of the yokes from transfercase to axle. for this example imagine the driveshaft rotated clockwise when propelling the truck forward when view from the rear: If you had the transfer case flange yoke at 12 and 6 oclock, and the first driveshaft yoke at 3 and 9pm, you would want the zerk at the 1:30 or 7:30 postition. For the rear u-joint, you would want it at the 4:30 or the 10:30 position. Make sense?

Bloodey hell yes Brett. Tremendous sense in fact. You're really on my wavelength. Woooooow. Thanks heaps. Just got to have a few more beers to take it all in. But I'm with you on this. Really I am.

Thankyou. (I'm forever in your debt in fact.)

Hey can I put you on my "buddy list".

 

[lostmarbles]

Just a sequel here.

As mentioned earlier in this thread, in my ignorance I had COMPLETELY misaligned the yokes on my front driveshaft when I had removed it for painting many moons ago. Vibrations should normally have been expected from this error but I think my sagged suspension and consequent "lack of significant drive-line angles" meant I noticed nothing untoward.

So a few days ago I unbolted the foremost flange on my front driveshaft and slipped the driveshaft apart at the splined joint (leaving the short end dangling from the "transfer case front-drive output flange").

It was then a simple matter to reconnect the splined joint with the yokes aligned properly (confirmed with taut string again) and with all the grease nipples on roughly the SAME side.

So anybody who thinks aligning the yokes perfectly is difficult - Think again. (I heard someone in another thread say they thought it was a specialist job or required special tools.)

I would have taken photos but the front crossmember gets in the way. (Lack of access to that end is why I chose to unbolt only the FRONT driveshaft flanged-joint.)

As usual - I reused the original flange bolts but simply applied fresh blue loctite to the threads. (I think money and time is wasted by always fitting fresh new bolts - These are the same ones that left the factory 29 years ago!)

 

[andrewfarmer]

How's this photo Andrew. I tied a piece of string on the driveshaft this time. (It just goes to show how much a camera can lie.)

Here's the new "better" photo. Now the yokes look perfectly aligned don't they?:

Still looks half a spline out to me. Only real way to tell is to take it out and look down it...

 

[lostmarbles]

Still looks half a spline out to me. Only real way to tell is to take it out and look down it...

Or perhaps I should drive to your favorite boghole (shown in your avatar). Then I could look down both driveshafts without too much trouble and save on the spanner work?

 

[74fjsemistock]

You have to take into consideration that you are South of the equater.Your crap spins counter-clockwise as you flush,regardless of your 1 vibration

 

[axlechassis]

^Yep ya gotta bear in mind how in NZ things are just different.