Engine: V8 crankshaft end play check

[M-Webb]

Now that I have the crank installed by in my 289 and the bearing clearances checked out to good, I went to check the end play clearance, suppose to be .003" - .006" according to the shop manual. Using the crank gear install tool from Phil Harris and a few extra large "machine bushings" I picked up at the local hardware store, and my dial indicator, the .003" shim that came in the motor seems to give me too much gap. So I removed it and now have no shim in it and am getting about .004" to .005" play, depending on how hard I torque the screw driver to force it. At rest the gap sits at about .0015", which I assume is maybe caused by assembly lube compression or something. To try to minimize that affect, I did not put any assembly lube on the thrust plate itself for now. The nut on the cam gear tool it pretty well snugged up tight, but not cranked super tight, didn't want to possibly flex the thrust plate.

As I did it, I was careful not to push on any part of the crank right at the gauge so as not to introduce extra flex that would throw off the measurement as I noticed that happened once. I guess the crank can flex enough to read it if do that.

As is, I can rotate the crank with one hand by grabbing the snout and turning it. It does seem to rotate fine with no odd scraping sounds or anything like that. Although it is now a bit tighter and takes more force to turn it that before. I assume it will loosen up some once broken in and lube on the thrust plate might help a little too.

Does all this sound about right, good? Is it OK to not have any shims there at all or does that seem suspect for some reason or another?


setup with the cam gear tool





1st pushed the crank forward with pressure to zero it out







then at rest with no pressure it is at about .0015"







then pushed it backwards, get about .004" - .005" max.

[StudeRich]

The clearances sure seem fine, but I have to say I have never taken one of many apart and found No Shims.
Possibly because they were original builds not today's with wear, Rebuilds.

And THEN, there is the controlling factor, the Front Main Bearing, that is likely Not identical to the OEM USA Bearings, shoulder thickness.

[M-Webb]

Yeah, the no shims at all does give me some pause given that there was one in it. But then again, the work done previously was less than stellar obviously, so that doesn't mean much. I don't get the impression anyone spent much time checking things too exactly previously.

And as they say, the specs. are the specs. and unless I'm doing something wrong, it does seem to be spec-ing out as needed without any shims and I was getting way beyond the .006" with the .003" shim that was in it, and even a bit beyond with a (1) .001" shim. The worn parts verses when everything brand new is probably a good reason why.

I also noticed with my micrometer that the shims don't seem to be exactly the nominal dimension, they are all a little thicker. Guess they round down the dimension so. So anyway, stacking up multiple shims adds up to even more than would expect if doing that, plus probably some bit of lube thickness too once that gets in there.

I also tried to loosen the bolts on the front main cap and fooled around with the position of it relative to the block 1/2 to make sure they are as perfectly aligned as possible to make sure that wasn't throwing things off, even if just a tiny bit. I might have got it to move very slightly, but not much. Even though there is some play in the bolts, I guess the caps can't actually move that much.

Maybe I will try it one more time with a .001" shim just to be sure and figure out what is best from there. I have a set of couple each .001", .005" and .009" shims I got for this exercise, plus the (1) .003" shim. But maybe I don't need any of them.

This old tech might not be rocket science level stuff, but the reality is that if you really try to get things per spec. by the book, some very small things can make a difference whether it actually meets spec. or not. It doesn't take much.

[oilnsteel]

I have to compliment you on the care and precision you are putting into the rebuild of this engine. It should be a sweet runner! JT

[M-Webb]

Thanks JT. But man, this is my first ever serious engine work, let alone a full rebuild. I'm just hoping it runs at all by the time I'm done with it to be honest, seriously!

To keep the progress going, I rechecked it again tonight with a .001" shim and got the same result as before basically, out of spec. somehow. So was repeatable, guess no shims is the answer. FWIW, the .001" shim actually measured out at .00125" thick, the .003" shim @ .00325, but the .005" was pretty close to .005", didn't bother with the .009". So if you are using shims, keep that in mind, measure, don't assume, especially if stacking them. And when installed, they seem to result in even larger spacing than the spot measure out at. Guess when taken altogether, the added spacing includes distortion on the shim from being cut out or something. The single .001" gave me about .008" gap compared to the .004"-.005" max. with no shim. So somehow adds a lot more than just the .00125" it spot measures out at.

Also, just to check it again with assembly lube in place to see how much that might change things, that gave me a little over .007" play, no shim, just Lucas assembly lube added. Assuming it is because it is pretty viscous, not squeezing out easily. So that was a little surprising and I guess now technically out of spec. No shims to take away, so not sure how could even improve that if needed to. So, guess it is what it is.

[M-Webb]

https://www.youtube.com/shorts/e1fifutSxao

[M-Webb]

After thinking about it a bit and re-testing things, I wasn't comfortable with the crank feeling tighter once I snugged up the thrust bearing and not having any shims at all. Just wasn't feeling right. I think I was trying too hard and putting too much pressure on things when I was checking the clearance. So I redid it with a .003" shim and assembly fully lubed with just some reasonable free pressure with a screw driver tucked pretty firmly in the gaps to tighten things up, not torqued hard to overly force it like I had done before. Doing this now, I get about .005" gap and that is within spec. and that is with the assembly lube. Now the crank turns freely but still no obvious slop in the end play. I put the gears back on and now the crank and cam rotate together, feels good. Next, put the rods and pistons back in tomorrow, keep going.















.

[StudeRich]

I sure don't want to worry you any more to cause more frustration unnecessarily, after all that doubting things.
But is that an illusion that the Woodruff Key on the Crank Gear does not look like it is large enough to fully lock into the Gear ?

[M-Webb]

Rich, yeah, guess you can't see it in that photo, but it is in there somewhere. And it fit properly in the slot on the crank hub and I don't think it could be any bigger. When seated in the slot, the ends stuck out past the end of the slot some. So I guess it is what it is. Is it usually more visible? I didn't get any photos of it exposed after I installed unfortunately. So I'd have to pull the gear back off again to check it. Not the end of the world at this point. But unless it really seems like an obvious problem, not sure what what I can do to improve it. Not that it means anything reassuring with this motor at this point, but it was the one that came out of it.

[StudeRich]

If you can shine a bright light into that groove and see that some part of the Key IS holding the gear from turning, then No problem.

[M-Webb]

I will, but the key was definitely in there and it was the width of the slot. I had to tap it in with a hammer to seat it. So it is for sure the correct width of the slot if nothing else.

[M-Webb]

I did shine a light in there and saw the key as expected. The end of it is about 1/4" or so back from the face of the gear, and no more slot length is visible, it can't really come out any further. So guess it is as good as factory intended.

[Topper2011]

Michael, the work you are doing is very detailed and tidy. When can I drop my engine off to you?

[M-Webb]

LOL, I'd wait to see if this one actually runs for more than a month or not first, or even at all! The proof will be in the pudding as they say. Hopefully we'll be having a pudding taste test here before too long. Speaking of, break over, I better get back out in the garage and finish up getting the pistons back in.....

[JoeHall]

I think Rich MAY be saying is the key must be TALL enough to fit into, and nearly bottom out in the slot in the gear, same as it does in the slot in the shaft. In the pic, I can clearly see its width is correct for the slot in the shaft, but the surface appears to be flush with the shaft, I cannot see where it rises to engage the slot in the gear. Hard to splain, but the key must be tall enough to fully engage the slot in the shaft AND the gear, otherwise it will not keep the gear from spinning on the shaft.

[StudeRich]

Exactly what I was saying Joe, in that last Pic we can't see ANY Key holding the Gear, only the Crank.
If it's there, it must be way back out of sight, and should not be.
I wonder if it could be upside down ?

[M-Webb]

Sorry, guess I’m missing something. The Woodruff keys for the timing gears for both the crank and the cam are in the slots in the snouts for each, and they each seem to fit perfectly fine, both in length and height above so they align the gears and keep them from slipping. The other empty slot in the end of the crank snout is for the 3rd key for the balancer. That one is not installed yet, slot is empty at the moment.

Am I missing something? Does that not make sense and seem correct? Because I don’t know how it could be any different. There was enough lip proud of the hubs to prevent any slippage movement on both those gears. In fact, I think the thrust plate barely fit over it to get that on. So I don’t think a taller key would even fit.

But I’m definitely no expert, so maybe I’m missing something.

[JoeHall]

M-W what you describe sounds exactly correct, it's just not visible in your pic. Maybe an octipal oclusion or something. LOL

[M-Webb]

Is this what you guys are questioning, the Woodruff key that holds the timing gear on the crank snout? Here is a pic that shows it in there and it is pretty much full of the slot. It sits about 1/4" or so back from the face of the timing gear. The timing gear is fully set against the thrust bearing, so can not go back any further as far as that goes. The key is installed properly to fit in the slot in the crank. Does this answer the question?

Same for the cam timing key, was installed as well. I still need to install the one for the balancer on the crank, will do that tonight as well so don't lose it between now and when get to that. I'll be sure to put the oil slinger back on first before I do.

[JoeHall]

Yep, can see it clearly now, and it looks perfect.

[M-Webb]

Thanks for confirming Joe. I have to question everything and can't take anything for granted since this is my 1st motor build and I'm trying to fix a lot of things that were not done right on this motor to begin with. I didn't have the luxury of taking a good motor apart first to learn anything from that exercise. I have to learn it all correctly going only this way. But since I can't trust how this motor was put together before I dug into it, I can't trust what I found taking it apart was done correctly. With that said, the Woodruff keys are pretty easy, kind of hard to mess those up. But I wouldn't put it past myself tbh, lol. Thanks for helping keep me on track guys, checking my work. I appreciate it.