Driveshaft woes

[scottm]

Scott,

The front shaft should have the two ears on each end at 90 degrees from each other, correct?

The rear shaft should have the two ears in line with each other.

Yep and yep.

"Appears to be"on the front because I think the front of the front driveshaft angles to the left at the front u-joint, instead of up & down like all the other u-joints I've ever seen on cars. The front u-joint is turned 90 to match that odd angle and still be out of phase with the rear u-joint.

 

[Safado]

Yep and yep.

"Appears to be"on the front because I think the front of the front driveshaft angles to the left at the front u-joint, instead of up & down like all the other u-joints I've ever seen on cars. The front u-joint is turned 90 to match that odd angle and still be out of phase with the rear u-joint.

Man Scott, You lose me more every time you say something...

I don't want to totally disreguard your posts because obviously you have some knowledge that might help in this area...but you're killing me man. Everytime I've discussed phasing in regaurds to drivelines, it's always the yokes that you look at. How can u-joints that look like this ( + ) ever be 90 degrees out of phase with eachother....or appear to be for that matter. Every time you rotate one of them 90 degrees it will just realign itself once again and be "in phase" as one might say. The yokes however look like this ( | ) and when you rotate one end 90 degrees you will have one one like thie ( | ) and one like this ( -- ) thus being out of phase. This is how us rednecks understand it...school me if you've got a better explination....and use pictures.

For those of you with the front in phase wanting to put it out of phase...it would seem pretty easy. Just remove the Sleeve Yoke and rotate it 90 degrees. An easy way to check youself to see if it lines up is to balance the rear yoke on a large socket the size of the u-joint. Then do the same with the front and verify with another socket that the u-joint in the front lines up perfectly with that socket. It may be a bit of a balancing act, but you'll get the picture once you've started. If it doesn't line up correctly, remove it once again and adjust it one groove until perfect.

 

[nyk438]

NYK....


STILL WAITING ON FOR AN ANSWER....

I poste this in the last thread of yours as well...but since taking the advice of those on this board doesn't seem to be your strong point, I'll say it again. To test the theory given to you by LCS...simply drop a DS, lock the CDL and see if the vibration goes away. Whis you have them off, grab the Dust Cover and see if you can rotate it any. If this really is the cause of the CLUNK when you engage your truck, it should be as loose as Junks momma. More than likely your clunk comes from play in the rear and or front pinion. Amazingly enough...you can also check this when your DS is off. Just grab the flange at the diff and see how much play you have. You can also check for play at the transfer case flanges, but would best be done with both shafts out....so do it between front and rear tests.

How long do you let your truck warm up before you slap it in gear? What RPM are you pulling? Personally I've noticed that if I'm in a hurry and slap it in Drive over 1.2k RPM I get a clunk. If I let it warm up to where it drops below 1k, there is no clunk. Give it a shot and .....


POST BACK UP!!!!!!!!!

Whoa whoa, sorry I was at home on Sat/Sunday when I was posting, I'm now in San Antonio and just got my cable modem today.

Sorry.


So if I drop the driveshaft (not take it totally off right?) and put the CDL on?


When the truck is warm it still has the clunk. When the driveshaft is dropped grab the flange and I assume move it up and down side to side manner. Just another thought, the truck was driven for a short period of time with the CDL on before I was under ownership. The light on the dash never went on so my dad was driving it with the CDL engaged, this could be teh cause of it right?

I'll only be able to investigate the problem this weekend, no tools yet up in my new place. Thanks for all the help sorry for the confusion about everything. I probaly should stop trying to do 3 things at once on the computer...

 

[concretejungle]

could be worse.

 

[cruiserdan]

could be worse.

What's wrong with that one? It looks like $$$ to me

 

[concretejungle]

Dan, whatchu think about the poster i'm sporting in the office? Nice ey!

 

[cruiserdan]

It makes me want some sand ladders.

 

[scottm]

Man Scott, You lose me more every time you say something....

Really I'm just making this stuff up

Best way to figure it out is with a socket set u-joint. When you try to use it at a sharp angle, the shaft after the u-joint doesn't turn smoothly. It kind of snaps around twice per rotation, and turns slowly between. It'll be obvious when you try it. Turning it slowly with a drill would help. You can imagine it wouldn't be good to have the driveshaft doing that to the axle on the highway. The beauty is that a second u-joint can rotate it's output faster when the first u-joint goes slow, the opposite effect, for a smooth rotation. Now everyone go out and play with your socket sets.

 

[Safado]

So if I drop the driveshaft (not take it totally off right?) and put the CDL on?

NOPE, TAKE IT ALL THE WAY OUT...THAT'S THE ONLY WAY YOU CAN DRIVE AROUND WITH IT.

The light on the dash never went on so my dad was driving it with the CDL engaged, this could be teh cause of it right?

IT MAY HAVE CONTRIBUTED TO THE SLACK IN THE T-CASE, JUST TEST IT FOR SLOP AND REPORT BACK.

 

[IdahoDoug]

Safedo,

For a simple and visually confirmed feature, this is actually quite complex. You've got it correct that your yokes should look like a + sign on the front, and a -- sign on the rear shaft. That's the simple visual part.

Here's the complex part. A drive shaft with two universal joints on it will produce nearly no vibration when the operating angles at both ends are the same and in one plane. Anything more than a zero angle produces axial force, and the greater the angle the greater the axial force. That's why lifted vehicles vibrate sometimes - the driveshaft operates at a steeper angle than designed and often one end has a different angle.

These forces largely cancel each other out when the yokes are in phase and that's the preferred setup.

Both of the 80's driveshafts are actually slightly out of aligment laterally, however, with the front more than the rear. So I don't fully understand what goes on when the shaft has two different planes to deal with in its rotation, but I'm guessing from what I know that Toyota found splitting the difference between the two planes (out of alignment horizontally, AND out of alignment laterally) by putting the joints out of phase provided the least vibration. If the shaft were only out of alignment horizontally, I'd expect the yokes to be in phase as they only have a single set of forces to deal with and this cancels them nicely.

DougM

 

[scottm]

Runs in the family

 

[cruisermaine]

Safedo,

For a simple and visually confirmed feature, this is actually quite complex. You've got it correct that your yokes should look like a + sign on the front, and a -- sign on the rear shaft. That's the simple visual part.
DougM

OK, now I am probably one of the least mechanically (repairs) experienced here but I can read and understand pictures (most of the time . Your statement above makes no sense to me. WRT to the driveshaft, the in-phase / out of phase issue as I see it in the manual concernes the positions of the fixed yoke relative to the sleeve yoke. I fail to see how a + sign description applies. I think Safedo's description was more on the mark here : the front drive shaft yokes should be ( l ) and ( -- ) and the rear ( l ) and ( l ). The flange yoke position is not relevent.

I will be dropping my front shaft this morning. Exactly what is involved in removing/rotating the sleeve yoke? Will it just pull right off or will I need a vice and a drift or something?

Peter

 

[scottm]

Go with the picture, it's worth a thousand words and ten thousand +, --, |.

 

[cruisermaine]

when replacing the spider bearings, do I really need the SST or is there a generic tool that will work as well?

 

[Safado]

Safedo,

For a simple and visually confirmed feature, this is actually quite complex. You've got it correct that your yokes should look like a + sign on the front, and a -- sign on the rear shaft. That's the simple visual part.

Here's the complex part. A drive shaft with two universal joints on it will produce nearly no vibration when the operating angles at both ends are the same and in one plane. Anything more than a zero angle produces axial force, and the greater the angle the greater the axial force. That's why lifted vehicles vibrate sometimes - the driveshaft operates at a steeper angle than designed and often one end has a different angle.

These forces largely cancel each other out when the yokes are in phase and that's the preferred setup.

Both of the 80's driveshafts are actually slightly out of aligment laterally, however, with the front more than the rear. So I don't fully understand what goes on when the shaft has two different planes to deal with in its rotation, but I'm guessing from what I know that Toyota found splitting the difference between the two planes (out of alignment horizontally, AND out of alignment laterally) by putting the joints out of phase provided the least vibration. If the shaft were only out of alignment horizontally, I'd expect the yokes to be in phase as they only have a single set of forces to deal with and this cancels them nicely.

DougM

I guess I didn't explain myself well enough in that description. The + symbol I was using was to illustrate the u-joint itself. And illustrating that there is no way to rotate it 90 degrees and not get a +. So talking about the orientation of the u-joint didn't seem to play any roll in phasing. Now do you get it?

Ok, look at the picture and think happy thoughts.

Cruisemain---you don't need an SST, but a press would come in handy. I've done it before on my Chev with a sledge and a socket, but it kinda makes you think about possible damage to the bearings what way. You're not replacing the u-joints are you?
As far as your question on rotating it back into phase...I would imagine that is all that is needed, but have never done it. Sorry.

 

[IdahoDoug]

Whups, my bad on the + and -- signs. I thought Safedo and I were on the same visual there with the yokes 90 degrees off each other as viewed from one end of the shaft - thus the + sign for the front shaft. In line with each other, they'd look like a minus sign as viewed along the shaft. The pictures are definitely the way to go, however. It's easy to drop the shaft, but the spider bearings/journals are a bit tougher. I think you need a selection of shims in order to end up with the right clearances, so pick these up, too.

DougM

 

[nakman]

Now everyone go out and play with your socket sets.

Scott, that was awesome, thank you so much for sharing that. Put the extension in the drill chuck, spun another one inside a hunk of pipe with the u-joint inbetween.. behaved just as you said it would. I'm pulling my driveshaft off now to investigate further.

yes, damnit, I too have the clunk now, worse than before..... why'd everyone have to start talking about it again?

 

[nakman]

Ok, so I pulled my rear driveshaft off, cleaned up the U-joints and greased up the splines. In the midst of cleaning, I completely rubbed off all of my alignment markings... :whoops:
No big deal, just put it back together per the drawing in the FSM, also on page 1 of this thread.. and then double-check the alignment by placing a 4' level across the outside of the propellors. It made a lot of sense at the time, the sleeve yoke and the propeller shaft are coplanar, as are both flange yokes... crap now I'm thinking that I put it together per the front driveshaft drawing...

Needless to say I've got a bunch of vibration now, at low and high speeds, both accelerating and decelerating. took the motorcycle to work. Last night in bed I was thinking that I put it together 180° from where it was before, and those little weights were causing my vibration, but now I'm thinking that I'm off by 90° like a total dumbass- because I had the FSM open in the garage, this thread open in the garage, with a crosscheck using the level... and I still screwed it up. guess you get what you pay for in a mechanic. I do have some questions:

1. Does the dust cover come off, or is it worth taking it off to better clean the splines? Is it threaded on, or pressed on... or should I not mess with it?

2. It doesn't matter how the driveshaft mounts to the diff & T-case, right? because those marks are gone too.. I mean the two flangs are parallel to each other, so all the vibration is in the shaft itself?

Oh and I still have the clunk. I think my spider bearing on the rear diff side is shot, in the middle of its travel (say +/- 30° it feels very loose, then towards the outside of its travel (between 30-40°) it's kinda tight. Should that feel consistent all the way through? I'm hopeful that new bearings make the clunk go away....

 

[97cruiser]

Nakman, I am still trying to track down a vibration and u-joints were something I replaced. Both my shafts u-joints, to some degree, were just as u stated (loose on the inside travel and tight on the outside travel) although my rear joints were in much worse shape than the front ones. I also had the front shaft balanced and trued since my vibration is gone with removal of front shaft.

So, did my occasional clunk leave after all this? No. Did my vibration leave after all this. No Don't know what else to tell ya.

Good Luck, Vince

 

[nakman]

Ok, so after further review, I assembled my rear driveshaft per the front driveshaft assembly drawing the other night. that won't happen again, rest assured. so I rotated it 90° yesterday, reinstalled, and the vibration is gone. whew!!

Now back to the clunk.. I'm going to flake on the run tomorrow, sadly, and keep after this. The clunk definitely got worse after a run 2 weeks ago, so I don't want to tack on another order of magnitude, since the 80 is my DD now that we sold our Taco.

Will start by doing the same PM work to the front driveshaft, then before I reinstall it will drive around a little in 2WD to see if the clunk persists. If it does, I'll put the front shaft back up, drop the rear, and drive around again.. try to see if that makes any difference. I would have done that last night while I had the rear off but I had to get the 80 out of the garage so I could do this guy's valve cover on his Honda.. Maybe I'll change the T-case gear oil too since I'm down there, even though what's in there is less than a year old, with maybe 7000 miles.

What happened to the rest of you guys dealing with this... did you figure it out?