Help a NOOB - A continuing saga

[Steeveedee]

Originally Posted by BRL

Not meaning to interrupt, but long ago a friend was towing his car with a Turbo-400 from Mississippi to CA. and I removed the driveshaft thinking that the trans. would be turning inside, but no pump would be lubing it on that long journey.

I then realized after he left that I hadn't marked the driveshaft for realignment, and mentioned it to someone.

Guy said it didn't matter, as the driveshaft itself is balanced so it will remain that way no matter how it's re-orientated.

Well, the friend didn't complain of vibration after he re-installed it in CA. so...?

He's talking about phasing of the u-joints themselves, not how the driveshaft mounts into the transmission or on the differential yoke. Since the driveshaft was only removed and not disassembled, there would not have been an issue. This is a common source of confusion. You put a plug in the transmission, right? Or did it mark its territory all the way home?

[ncpetersc]

Originally Posted by Steeveedee

I know that working on the ground gig. That's how I've been doing it since I quit working as a mechanic. Maybe try cranking up the force on the bearing. Worst that happens is yo break the bearing and have to cut the inner race with a Dremel cutoff wheel. If that's what happens, cut into the race just enough to get a chisel into it and give it a good smack. Been there with that. too!

Well I did break something. I decided more force just like you said. I did something I had intentionally not done yet, just trying to be careful, used my impact drill on the puller. I should have gone slower maybe, but I didn't just hit it like a maniac either, just gave it short hits watching the puller screw to make sure it was bumping some.

Then SNAP! The puller came off. Nobody hurt . Looking at the bearing, it HAD MOVED a few mm! Thrilled at that. Unfortunately I did something (probably stupid). From the beginning what I used to brace the center of the puller against was just the original bolt that held the yoke on. It's just the first ting that came to mind I guess, and I really had no idea how frozen this thing was going to be. Anyway, the bearing had moved, AND that bolt was BENT!

I had it it in maybe about 6 full threads to begin with. I guess more could have been better (less hanging out to bend due to any off centeredness) or just have made a smarter decision on what to put over the spindle in the first place. BUT, impact drill in hand I swapped sockets and slowly backed it out. Threads were toast, and I got scared (about drive shaft). Turns out though, the bolt took the hit, thankfully. (Jumping ahead to bolt outcome) New one from the autoparts store went in very smoothly, one chase maybe to get some thread remnants loose, but it was good. PHEW!

Back to the bearing. Used a part from the borrowed ball joint press, a nice stout cup that I could place against the face of the shaft, I set back up to get back to the bearing. Needless to say since it had already "broken" free, it came off easily!

[ncpetersc]

Originally Posted by BRL

Not meaning to interrupt, but long ago a friend was towing his car with a Turbo-400 from Mississippi to CA. and I removed the driveshaft thinking that the trans. would be turning inside, but no pump would be lubing it on that long journey.

I then realized after he left that I hadn't marked the driveshaft for realignment, and mentioned it to someone.

Guy said it didn't matter, as the driveshaft itself is balanced so it will remain that way no matter how it's re-orientated.

Well, the friend didn't complain of vibration after he re-installed it in CA. so...?

Been thinking a LOT about this, and I will tell you why...

Though I did mark every single connection on this thing before disassembly with nice crayon marks. (I am doing all the ujoints too) In at least one instance while working, or going to install a new ujoint, I could not positively find my mark! All of the handling with the greasy hands can make quick work of a crayon mark. I *think* I saw a remnant of it, but can't be sure. So I am worried.

Here are some of my thoughts on this right now.

First the vehicle has not moved since removal. So trans and diff should be as they were.
You can only put the front of the front shaft into the tranny one way.
The yoke on the splines of the front shaft I know were marked positively.

I think *if* I get that yoke right, the only thing I could mess up is getting the rear shaft a full 180 out when connecting the two. That would definitely be a problem, but from what I read/hear I'll know.

But I am crossing my fingers that I got it right. I plan on checking my pre-disassembly pictures for any hints (weights etc.) to confirm. It's a paint marker more me next time!

But in a nutshell given the tranny is indexed, I think the only key for this two piece shaft is the yoke back on the right spline, then the back shaft to front shaft u-joint back in the right orientation, only two possibilities for it (correct, or 180 out).

[ncpetersc]

Originally Posted by Steeveedee

He's talking about phasing of the u-joints themselves, not how the driveshaft mounts into the transmission or on the differential yoke. Since the driveshaft was only removed and not disassembled, there would not have been an issue. This is a common source of confusion. You put a plug in the transmission, right? Or did it mark its territory all the way home?

Oh gosh, I didn't plug transmission at all, is it hurt?

And maybe I didn't mention before that I did disassemble, had one or more suggest doing u-joints while it was out. (I had to remove center u-joint to get to the bolt for the yoke anyway).

But, please tell me more about what you mean regarding the transmission. I'm worried again (or more) now.

[Steeveedee]

No worries on the transmission, as long as no oil ran out of it.

I'd forgotten the order of assembly, as for the bolt and u-joint. The trans and the diff don't care at all about the driveshaft except for it being properly installed. What is important is that the u-joints for each half of the driveshaft are lined up, on the spline. If you have a vibration when you get it back together, the worst case is that you would have to rotate the rear section half a turn, if the u-joints are properly installed. I've boogered some myself, back in the dim and misty past. Once you get it back together, share a picture with us. That would be the easiest way to verify it. You could look at your previous picture for reference, as well. Perhaps there are some distinguishing features that will help you.

[ncpetersc]

Okay, I certainly messed this up, we'll just see how bad. I can see from my picture (best one is from post 218). That I installed the wrong end of the rear shaft to the yoke in the middle. Gonna fix that now.

I would like to ask opinions on the front shaft. Mine currently appears to have both yokes aligned with each other. I think that looks true in the picture, but would like opinions. I thought I got that part marked and didn't lose it.

Thing is the manuals says to rotate the one on the spline 4 teeth vs the starting point (aligned). It is a ten tooth spline so that would be *nearly* 180 degress.

I guess it's possible someone long ago put it together this way (without the 4 tooth offset) and had it rebalanced? Or it was put together wrong some time back and is unbalanced?

I will try to put it back in and drive, but I think if I feel anything I might be trying to find someplace to balance it in the future.

I was even thinking about not fixing the rear shaft, but I am going to anyway. Was just thinking that the weight is the same distance from center wether its front or back of shaft.

Off to turn the back around now, but will check back to see what you all think from the pic if you can. I see front shaft having yokes in line, which is the way I put it back together as well.

THANKS

[Steeveedee]

Which manual are you using?

I'm using this one

http://www.mediafire.com/file/e7v2am...o_60_Truck.pdf

but did not find the 4 tooth rotation on the spline referenced, though I have seen it elsewhere. Maybe I missed it in this manual.

OK, I also have The Chevrolet Motor Division paper manual for 1972 (finally found it!), and it gives the 4-tooth rotation for the spline. Page 4-24

[BRL]

Originally Posted by Steeveedee

...Since the driveshaft was only removed and not disassembled, there would not have been an issue. This is a common source of confusion.

Oh OK, the one I removed was a one piece driveshaft, and yes I was always confused why a person would have to mark it.

But of course we're talking about a two piece here, so I now see why the rear should stay aligned with the front.

Thank you for clearing that up.

Originally Posted by Steeveedee

You put a plug in the transmission, right? Or did it mark its territory all the way home?

...um...that would explain the dark stripe and all the cars behind him flying off of I-20 West!

Originally Posted by ncpetersc

Oh gosh, I didn't plug transmission at all, is it hurt?

And maybe I didn't mention before that I did disassemble, had one or more suggest doing u-joints while it was out. (I had to remove center u-joint to get to the bolt for the yoke anyway).

But, please tell me more about what you mean regarding the transmission. I'm worried again (or more) now.

I believe Steeveedee was referring to the tranny fluid coming out the back upon acceleration without a plug back there.

Stationary is fine and may only leak a bit of what fluid is above the bottom of the rear yoke opening.

Probably wouldn't hurt to tie a plastic bag or something around that opening anyway, to prevent dirt or dusty junk from getting into your transmission.

[Steeveedee]

Originally Posted by BRL

Oh OK, the one I removed was a one piece driveshaft, and yes I was always confused why a person would have to mark it.

But of course we're talking about a two piece here, so I now see why the rear should stay aligned with the front.

Thank you for clearing that up.




...um...that would explain the dark stripe and all the cars behind him flying off of I-20 West! My reply:



I believe Steeveedee was referring to the tranny fluid coming out the back upon acceleration without a plug back there.

Stationary is fine and may only leak a bit of what fluid is above the bottom of the rear yoke opening.

Probably wouldn't hurt to tie a plastic bag or something around that opening anyway, to prevent dirt or dusty junk from getting into your transmission.

Agreed, about the bag. Unless he wants his driveway not to rust.

[ncpetersc]

Originally Posted by Steeveedee

Which manual are you using?

I'm using this one

http://www.mediafire.com/file/e7v2am...o_60_Truck.pdf

but did not find the 4 tooth rotation on the spline referenced, though I have seen it elsewhere. Maybe I missed it in this manual.

OK, I also have The Chevrolet Motor Division paper manual for 1972 (finally found it!), and it gives the 4-tooth rotation for the spline. Page 4-24

My truck is a '72 so using the manual shown in image. The instructions for installation are:
Installation
1. For models with one piece propeller shafts, slide
shaft into transmission and attach re a r U-joint axle.
Torque bolts to specifications.
2. For models with two piece shafts, install front half
into transmission and bolt support to crossmember.
a. Slide grease cap and gasket onto re a r splines.
b. Rotate shaft so front U-joint trunnion is in a
vertical position.
c. Take re a r propeller shaft and before installing
align U-joint trunnions in same vertical position
as in step b (at this point all U-joint trunnions
should be vertical), (fig. 51). Then, note re la tionship
of front shaft and re a r shaft spline position.
For all models except model CE31403
(157" W0B. 307 CIO, V-8 Engine) Rotate re a r
shaft four splines toward left side of vehicle
(fig. 42) and install re a r shaft to front shaft. For
Model CE31403 rotate 2 splines. Attach re a r
U-joint to axle. Tighten grease cap.
d. Torque bearing support to crossmember and Ujoint
to axle attachments to specifications.

One note: I have the different style carrier mount than what is shown in the picture. The one with mounting bolts parallel to drive shaft. I cannot install this way because I cannot tighten the yoke over the splines with that u-joint installed. So I am assembling entire shaft out of truck, which is how I took it out.

[ncpetersc]

Originally Posted by Steeveedee

Agreed, about the bag. Unless he wants his driveway not to rust.

Been sitting there uncovered since Saturday, hopefully nothing terrible happened. Will cover tonight if I don't decide to re-install the propeller shaft.

[Steeveedee]

I was just gassing off there. If it didn't leak when you pulled the shaft out, it won't be leaking now.

Now I'm curious as to what to do with my own driveshaft. The '70 manual doesn't say anything about the spline. The Chilton's for '70-'80 Chevy trucks says don't do it at all. Someone is wrong, but for your truck you have it in writing for your specific year.

[ncpetersc]

Originally Posted by Steeveedee

I was just gassing off there. If it didn't leak when you pulled the shaft out, it won't be leaking now.

Now I'm curious as to what to do with my own driveshaft. The '70 manual doesn't say anything about the spline. The Chilton's for '70-'80 Chevy trucks says don't do it at all. Someone is wrong, but for your truck you have it in writing for your specific year.

I do but, but the picture of what I pulled out before I disassembled it doesn't seem to jive with "4 teeth" either. So I still have questions. But I think my first choice is to put it back together the way it was, and forget the manual for now.

I actually created a little (probably confusing) diagram to help me asses where it's at currently. It depicts the transmission yoke as vertical like in the manual, so the front of the drive shaft horizontal (mating). Then it shows the yoke on the splined end in three possible positions. 2,3, or 4 teeth rotated. (ALL THIS VIEWED FROM REAR, LOOKING FORWARD TOWARDS TRANNY)

[ncpetersc]

Originally Posted by Steeveedee

I was just gassing off there. If it didn't leak when you pulled the shaft out, it won't be leaking now.

Now I'm curious as to what to do with my own driveshaft. The '70 manual doesn't say anything about the spline. The Chilton's for '70-'80 Chevy trucks says don't do it at all. Someone is wrong, but for your truck you have it in writing for your specific year.

As far as what to do with yours, I'd say put it back together the way it is now. If you have no balance/vibration issues, keept it the same?

[Steeveedee]

Yeah, I'll have to look into it. I don't have any squeaky u-joints though (they have grease fittings), so it'll be awhile.

[ncpetersc]

Well, I decided I'd agonized about it enough, and was at least certain I had it back together the way it came out, so I put it back in the truck last night.

I only drove it at lower speeds around the block. Didn't feel like breaking anything before I got one good night's sleep . If I would say anything at all, it is that nothing changed from before. Nothing good, nothing bad.

That carrier bearing dampener did need replacing, and now I have new u-joints so it was worth doing I guess. But it did not eliminate the "whine" that I thought might be caused by the bearing being wobbly.

A new observation about that "whine". It becomes prominent as speed increases, and I think I mentioned I hear it when cruising above 30 or so. What I noticed last night was that it goes away when I get off the pedal. Comes back when I ease back onto the pedal. Tranny?

I remain confused about the manual says about clocking the rear shaft. About as accurate as I can check, I appear 90 degrees out. With one bearing face of the tranny yoke on a flat surface, the front yoke of the rear shaft appears to lay flat as well. Doesn't make sense to me, as each "tooth" should be 36 degrees. But that's how I had it marked (pic) and that's how it looks in the pic when I first pulled it out. I put 3 center punch marks on the shaft, the center one lining up with the missing tooth in the yoke before I pulled it off.


I think I said something incorrect in an earlier post. I had thought I read, and assumed, that I could only put the shaft back in the transmission one way. That is not correct, because I was off a tooth the first time I did, so was a little concerned when the rear trunion wasn't lining up with the differential properly. Pulled it out, rotated one tooth, and installation wasn't too bad.

In the end, I have myself believing, the only crucial thing to reassemble as it was is that center/splined yoke to maintain balance of the shaft. How it's installed in the front and back should not affect balance.

Another reason, I only went for a slow short test ride... I need to put more grease in the rear u-joint. But I can't get my gun on it! I could only put so much in this one before installing because the grease caps aren't retained until re-installed with the straps. In hindsight I should have just loaded it up and squeezed them together during install, but I didn't anticipate not being able to get to it. I even got it into an ideal position, and removed a strap bolt to get access, but my grease tip won't get there. I'll be investigating slim profile grease gun attachments today... I hope something is available.

I finally pulled pictures off my phone from this ordeal, pulled the yoke off. Jaws in bearing cap holes maybe not best idea. Probably could have tapped it off with a hammer from the other side. But it wasn't tough to get off.

The setup that eventually let to me destroying the bolt.

But at least that sucker finally came off!!

Some thoughts on u-joints. Not rocket science, but they get old quick! It's really unfortunate that you can't press the caps all the way out. At least for me "working them out" the last bit was a serious PITA, although I did get better at it. Not having proper tools like at least a vice didn't help me. I basically used a vice grip as tight as I could on the cap and used a stout screw driver to pry against the yoke. I got better at this by realizing prying hard wasn't as important as prying evenly. Clamp the pliers on, pry a little in 2 or 3 spots on one side, then 2 or 3 on the other. Reclamp the pliers 90 degrees from where they were last. pry pry pry, other side pry pry pry and so on. Lot's of penetrating fluid also... They come out eventually.. :P
Oh, and before installing new ones a good yoke cleaning goes a LONG way, emery cloth, clean out that spring clip recess, and lube a bit.


Oh, what next, back to figuring out my timing weirdness I guess.

[Steeveedee]

The whine is probably your differential. If it isn't too loud, you can just drive it. I don't recall if you pulled the differential cover off or not, yet. If you haven't yet, take pics of the gears and post them.

[ncpetersc]

Originally Posted by Steeveedee

The whine is probably your differential. If it isn't too loud, you can just drive it. I don't recall if you pulled the differential cover off or not, yet. If you haven't yet, take pics of the gears and post them.

Didn't pull cover, just checked oil level, which was good. So I avoided pulling cover. I've never done it, and ready about difficulties putting it back without leaks. Before putting the driveshaft back in I did grab the pinion shaft to check for play, and there is a little wiggle. Don't know what is normal.

It's not horribly loud so I guess I'll put it down the list a bit.

Oh the list........ lol

Thanks again!

[ncpetersc]

My brother sent me this; It's a picture of a picture, so I apologize for the quality. That's me on the right, and the original owner (my Grandfather) on the left.

I guess we were just settin' out by the truck having a beer and a chat...

[slikside]

That pic is priceless!

[ncpetersc]

Originally Posted by 68 P.O.S.

Why do you still have the TCS connected, and does it actually work still?? If it works, and correctly, it's not allowing the vac advance to come in just yet as designed. I would disconnect it and remove the wiring; it was an early, crude emissions thing and it provides no benefit to your engine and only stops your vac advance from working correctly. The only people who really still use the TCS are those doing a factory correct restore, or they just don't understand the TCS. Plug your vac advance can directly to manifold vac and you should see the idle increase. If not, you have a bad vac can. Now you need to find out how many degrees of advance your vac can provides. You want it to be around 10 degrees, or you'll probably get pinging if it has more than that.

After staring at the motor for a while and considered my options, I decided I wasn't going to be able to manually turn the thing without taking too much apart. So instead I decided to see what I could figure out just using the starter.

I pulled the coil wire from the distributor and pulled the #1 plug. It didn't take a whole lot of tries to get it to hit +4 and 0 degrees on the marking tab. Both of these positions the piston seemed to be TDC to me, could touch it with a screwdriver just inside the plug whole. Since the ring on the balancer slipping seemed a little less likely (though possible I am sure) I decided to go ahead and assume my balancer mark is fine, and has not slipped.

Call me lazy, I'll agree with you, and I'll just hope it's a safe assumption for now.

So, then I was going to try to take the TCS business out of the picture. But before I did I set the "initial" back down to 10deg or so, expecting the 22deg could be too much with vacuum advance about to be added. I initially just bypassed the solenoid but observed no additional vacuum. It turns out that I was set up with a "ported" vacuum port and the TCS solenoid.

I switched to using a manifold vac port, as suggested. My vac advance gives about 20 degrees it turns out. My dist must have moved a bit (it wasn't tightened yet) but I had 9 BTDC with the vacuum disconnected and 29 with it connected. Does this sound alright? I know 10 deg vac advance was mentioned, but I have certainly heard from others that they have around 20deg.

So I am currently thinking that it is very likely that I never had any vacuum advance before, and the TCS solenoid didn't function.

I rev'd up the engine and observed a total of about 52 degrees timing. I hope this is all in but I really hate rev'ing it that high under the hood for some reason, so I might have chickened out a little. I probably observed it about 3000rpm at least.

So now that I am on full manifold vacuum, I'm trying to figure out proper next steps. It seems like you can get varying opinions on this subject, and that's fine, just looking for ideas.

Personally, I have been convinced by some things I read that using a vacuum gauge to time and to tune the idle circuit is a good way. But I am not knowledgeable, maybe just gullible.

What's that definitive way to time and adjust idle to perfection?

[68 P.O.S.]

I would use a piston stop and do it right to be 100% sure. My luck, I would go with my assumption and end up grenading the engine �� But if you're comfortable with it, cool.

Yeah, it sounds like you probably never had any vacuum advance going on. Good job putting it on manifold vacuum. No, 20 degrees vacuum advance is way too much. Yes, other people run 20 degrees, likely on ported vacuum, because they probably don't understand it. Distributors in the 70's/80's had high vaccum advance to make up for the late timing they ran for emissions. You want 8-12 degrees vacuum advance..

The next step now that you're on manifold vacuum is to get an HEI. Haha.

Tuning with a vac gauge is a good idea, but timing with a vac gauge isn't. I suppose you could adjust initial timing for best vacuum and then use a timing light to fine tune the total advance.

On a carbed engine, there is no definitive way to adjust timing and idle to perfection, besides adding fuel injection. Too many environmental factors that change everyday. You can get a wideband and a carb calibration kit and get damn close.