Flywheel Housing Alignment

[Smitty]

Hi All,


I have been running a indicator around this housing. Red book says there should be a maximum of .006 variation. Is this what other engine re builders are getting? I seem to be getting some erratic readings that don't make a lot of sense.
Thoughts? Thanks, Steve

[jb-ob]

80 years later most clutch housings are either distorted or cracked.


Beyond the linkage mounting ears, I found it necessary to shim at the point where the housing meets the block at the four bolt holes.


I kept records of each combination until I found the point with in limits.


It takes patience.

[kenparker]

I cannot tell from the picture, but, is your engne sitting on the engine stand horizontal or vertical. If it is sitting horizontal - as you turn the crankshaft the shaft will move forward and back a few thousands of an inch -the distance of the thrust movenent in the shaft. This affect the measurments in your dial indicator.


Turn the engine vertical or at least 45 degrees so all the thrust is moving down. The shaft will ride against the thrust surface of thebabbit and you will get a more consistant dial reaaduing.. clear as mud??? ken

[Smitty]

That's good to know, I added and removed shims where the accelerator bolts go but that was not helping much. Taking the time to work that detail out must improve operation and shifting.

[Smitty]

The engine is sitting vertical on a Wilson engine stand. Sure makes it easier to work on..

[Mulletwagon]

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The critical locations for measurement are 9, 12, and 3 o'clock. Also be sure to check the flywheel wobble. All important to minimize clutch chatter. Good advice from Ken regarding axial movement of the crank during measurement. Please share the final result. Good Luck.

[CT Jack]

This method of gauging run out is confusing. Suppose the snap ring diameter in the case exceeds the .006" limit due to it being out of round in a free state? This has nothing to do with the engine shaft. It seems to me this dimension should be verified before trying to determine if the case is concentrically located relative to the shaft. It appears there are 2 locating pins that locates the case. These were used to machine the snap diameter that is being indicated. Once you verify that the case is within spec then you can use the setup shown in the photo to check run out relative to the case.

[Jack Shaft]

I went through 6 used housings before I found an true one,Ford did about 8 revisions in production,the best are late '31's,they have ribs on the outside along the bottom.An easy test for cracking is to balance it with one finger and whack it with a wrench,it should ring...if it clanks its cracked.

The reason its done is to insure crankshaft/transmission input shaft alignment,so the clutch disc fully and evenly contacts the flywheel on application.

[Kohnke Rebabbitting]

DO NOT shim under the 4 housing bolts, as this will warp a usable housing in the wrong places.

The first thing is you have to have a level crank flange, and also a crank that is centered, in the babbitt, between the main, bolt holes. with out it your wasting your time. If that is off, your housing will be also. It is flange, to housing is what your trying to level. So if your crank is left or right by .010, The pilot shaft will be off, out of alignment, also.

Many Guys think you have to have some kind of level flywheel housing. I have never had one I couldn't level, no big deal. We have built in access, of 350 A engines, and many more then that, in babbitt jobs, where the customer also wanted us to install the flywheel housing.

You have to do two steps, to get a level, 4 point contact, to bolt the bell housing to.

First, get 9:00, and 3:00 to read the same, just the sides, first. Coarse adjustment, will not work. You have to have Brass, shim stock in, .001, and .002 thousandths, when you need it.

Movement for the side adjust, is set by shims put under the two top bolts, From side to side, chances are, your shim packs, will be different thicknesses, and 9 & 3 should be with in 1, to 2 thousandths.

When that is done, now you do the top, and bottom, 12, and 6, the only thing that is important here is that they both are, the same. This movement here, up or down, what ever you put in, or take out, they have to be equal, both sides.

They may, or may not be close to the sides, but what you want is that the bell housing will be square, with the flywheel housing, and engine.

We always let the first adjustment set for 24 hours for warping, and also the 12, and 6 setting.

Herm.

[Russ/40]

Herm, I'm a bit confused as to your shimming process. Not clear to me where you use shims, other than the two top bolts that take the .010" slotted shims. Could you expound as to your shimming? The photo that shows Indian Head shellac applied on the top portion of the gasket. What's going on there? Shims under the gasket, or???

[Kohnke Rebabbitting]

Originally Posted by Russ/40

Herm, I'm a bit confused as to your shimming process. Not clear to me where you use shims, other than the two top bolts that take the .010" slotted shims. Could you expound as to your shimming? The photo that shows Indian Head shellac applied on the top portion of the gasket. What's going on there? Shims under the gasket, or???

The gasket cement go's on the top, and bottom of the gasket, I just stopped in the middle of the job, to take a picture.

Ok, you have 4 bolts in the middle of the housing, NEVER us shims there. The housing has to set level on the block, to seal the cam gasket, you would also take a chance on distorting, or cracking, the housing, and it is not needed for anything, anyway.

The The two bolts that are out side of the housing, at the Top, are the ones that will take shims, if needed. As far as shim thickness, there are times that a .010 thickness is to much, and you will not use it. 90% of the time, you will use, .003, .002, and .001 thousandths thickness.

NO. 1., The first thing you do is set 9:00, and 3:00, to as close to Zero as you can get, about zero, to .002. You will have a different thickness of shim packs under each bolt, most of the time. Leave that, 24 hours, and then readjust, as needed.

No2, second step, 12:00, and 6;00 have to be as close to the same reading, as possible, with each other, they do not have to be the same, as 9 and 3. Now again, you leave it for 24 hours. The shim packs this time adjusting will be even in thickness, +, or -, to get it right.

So what you have now is 4 equal points for the bell housing, to bolt to, 9 & 3, and 12 & 6. So now the pilot shaft, will bolt, in alignment with the pilot bearing, if the crank is ground, and set correctly.

If you use a to thin of a gasket, it sometimes does not take shims, don't remove metal, use a thicker gasket.

Herm.

[jb-ob]

Herm,


As a 'paint guy' I promise not to pretend to be a machinist if you promise never to attempt hand lettering.


I now understand setting the flywheel to the crank flange and the relationship to everything that goes on behind that point.
I always thought the issue was with the clutch housing alignment to block.


Since after 90 years of abuse most clutch housings are no longer factory true, how do you compensate for that ?


Jim.B

[Patrick L.]

Originally Posted by jb-ob

Herm,


As a 'paint guy' I promise not to pretend to be a machinist if you promise never to attempt hand lettering.


I now understand setting the flywheel to the crank flange and the relationship to everything that goes on behind that point.
I always thought the issue was with the clutch housing alignment to block.


Since after 90 years of abuse most clutch housings are no longer factory true, how do you compensate for that ?


Jim.B

I've milled them and then have even hand filed once installed. Its a long process. Mine was the worst [ .032"] and could only get to .008", but its fine.

[Kohnke Rebabbitting]

Originally Posted by jb-ob

Herm,


As a 'paint guy' I promise not to pretend to be a machinist if you promise never to attempt hand lettering.


I now understand setting the flywheel to the crank flange and the relationship to everything that goes on behind that point.
I always thought the issue was with the clutch housing alignment to block.


Since after 90 years of abuse most clutch housings are no longer factory true, how do you compensate for that ?


Jim.B

There is nothing you can do to change the alignment with the bell housing that bolts to the transmission, and flywheel housing, as it not adjustable. So, the flywheel housing, that, is what has to be square with the pilot shaft. So if you get 4 points, that are square on the flywheel housing, the bell housing has to bolt up in correct manner.

Herm.

[Kohnke Rebabbitting]

Originally Posted by Patrick L.

I've milled them and then have even hand filed once installed. Its a long process. Mine was the worst [ .032"] and could only get to .008", but its fine.

I have had a lot of housings that were off .030 thousandths, and adjusting, and a little time to come back to shape, I have never had one, I couldn't align.

Herm.

[Russ/40]

[QUOTE=Kohnke Rebabbitting;1

So what you have now is 4 equal points for the bell housing, to bolt to, 9 & 3, and 12 & 6. So now the pilot shaft, will bolt, in alignment with the pilot bearing, if the crank is ground, and set correctly.Herm.[/QUOTE]

SO, whether doing the 9 & 3, or the 12 & 6, the same two top shim packs are used.?

[Chuck Sea/Tac]

Herms way works great, I’ve done it on several different engines. It’s amazing how the shims shift the run out.

[Kohnke Rebabbitting]

Originally Posted by Russ/40

SO, whether doing the 9 & 3, or the 12 & 6, the same two top shim packs are used.?

Think about it as two separate operations, as they are.

1. is setting each side, to read the same, or not over .003, difference. Doing this you will have, uneven stacks of shims, most likely.

2. next, indicate top, and bottom, and get them to read the same. They do not have to read the same as the sides. When adjusting the top and bottom, what ever you remove, or add, both bolts will receive the same same.

You will be done when sides read the same, and top, and bottom read the same.

Remember, you have to give it time to warp, into it, ( Acclimate ) !

Herm.

[Patrick L.]

Originally Posted by Kohnke Rebabbitting

I have had a lot of housings that were off .030 thousandths, and adjusting, and a little time to come back to shape, I have never had one, I couldn't align.

Herm.

I'm pretty patient, but, maybe not as patient as you. Plus you've done a whole lot more than I have. I don't think I've tried your method, I've just muddled thru. I'm also doing them in the car. I thought I might still get some shake at the .008", but, since it was mine I tried it. Its OK.

[David R.]

Herm, thanks so much for taking the time to go into such a detailed explanation and adding the excellent photos. I had to read through it a couple times, but after I got it it seems pretty simple, (in theory that is). What type shims do you use, as the horse shoe type seem to only come in .010 ?

[Dan McEachern]

Another reason you can't shim between the 4 mounting holes is that the rear cam bearing seal relies on those two surfaces being in contact. Shims on the cam side for sure would compromise that seal. Then you will be screaming at your engine builder that the rear main is leaking when its the cam bearing.

[jb-ob]

Dan,


Since most block to clutch housing gaskets are made today from thick cardboard in stead of paper, I'm not expecting a problem.
I'll get back to you.

[Jack Shaft]

But you can gain some adjustment usings horseshoe shims and gasket ..one or the other,or none..I have none on mine,no horseshoes,no gasket,just sealant..

[Russ/40]

Herm, your most patient and very helpful. I appreciate the generous giving of your time to clarify my many questions. I was having a problem with both operations with the same two adjustments. The concept of essentially training the material to come into alignment made the light come on in my head.

[jb-ob]

Herm,


Who gets the job of humping that 65 pound flywheel on & off the crank flange during the shimming process ?


If from your experience (I don't doubt) that most/all crank flange to flywheel surfaces are no longer factory 'true', why not a fly cut to both ?


(And avoid the hernia surgery.)


jb

[daren007]

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I have been told to work on 1,3 and 9. forget about 6. Once you bolt the housing up it will take care of 6. Makes the process a whole lot easier.

[Kohnke Rebabbitting]

Originally Posted by David R.

Herm, thanks so much for taking the time to go into such a detailed explanation and adding the excellent photos. I had to read through it a couple times, but after I got it it seems pretty simple, (in theory that is). What type shims do you use, as the horse shoe type seem to only come in .010 ?

.003, .002, and .001 thousandths thickness. You can use old main shims, cut down, fronts, and centers, as they are .002, and .003's. McMaster-Carr carries .001, and .002 in 12" sheets.

Write down what the thickness of the finished shim pack are, right, and left, just in case, a pack would fall.

Herm.

[Kohnke Rebabbitting]

Originally Posted by Russ/40

SO, whether doing the 9 & 3, or the 12 & 6, the same two top shim packs are used.?

Yes, But!

9 & 3 can be 2 different thickness of shim packs.

12 & 6 will be equal, when adding, or subtracting, from the stack.

Herm.

[Kohnke Rebabbitting]

Originally Posted by jb-ob

Herm,


Who gets the job of humping that 65 pound flywheel on & off the crank flange during the shimming process ?


If from your experience (I don't doubt) that most/all crank flange to flywheel surfaces are no longer factory 'true', why not a fly cut to both ?


(And avoid the hernia surgery.)


jb

When grinding the rear crank flange, you should have just gotten done grinding, all 3 mains. Then is the time to grind the cranks, rear flange. There will be no better time, that the crank journals, will align with the flange, any better. By using a crank grinder, no set up time, it is already done, and it will do a smoother , more accurate job.

The flywheel, does not have a part to play in setting the flywheel housing. They are set on once, and bolted down, and checked for off center, and then for wobble. The one in pictures shows 0, in 1 full circle. The wobble shows, .001 thousandths, meaning, correction would be .000-50, 1/2 thousandths.

If you grind a crank square, and on center line, and align bore square, set the flywheel housing square, grind the flywheel square, you can eliminate a lot of engine problems.

Herm.

[Kohnke Rebabbitting]

Originally Posted by daren007

I have been told to work on 1,3 and 9. forget about 6. Once you bolt the housing up it will take care of 6. Makes the process a whole lot easier.

Well, Daren, I Agree it would sure would make it easier.

[daren007]

Correction, One should be 12.

[jb-ob]

Herm,


Like others, thanks for sharing. I'm always in your audience reading your posts. I've gained a much better understanding.


I have a very early brass car collector that allows me to use their shop. After watching me fuss with some A parts, they complimented my efforts by asking if I knew what I had when finished ?


"It still just a Ford ."

[jhowes]

I would also like to ask Herm why brass shims, I have steel shims, isn't that OK to use. Also someone mentioned doing this in the car. Is that possible? Jack

[Jack Shaft]

It is common to do this repair on heavy trucks in frame,just be careful when turning the crank you don't 'force' the thrust clearance.

[Kohnke Rebabbitting]

Originally Posted by jhowes

I would also like to ask Herm why brass shims, I have steel shims, isn't that OK to use. Also someone mentioned doing this in the car. Is that possible? Jack

Steel shims are quite alright, I just don't have any in the shop, as we don't use them for any thing. But I have a lot of brass that we use every day.

In the Car? I won't say anything about why it can't be done perfect, and I think most of you know why. I will say, if it had to be done that why, I couldn't do it at all, but I am not them.

Herm.

[Kohnke Rebabbitting]

Originally Posted by daren007

I have been told to work on 1,3 and 9. forget about 6. Once you bolt the housing up it will take care of 6. Makes the process a whole lot easier.

Daren, this is my opinion.

9, 12, and 3 getting squared is good, but the bottom has a tendency to be off the worst. 0 to maybe 16? When the bell housing tightens up, yes it will pull together, at the bottom, but when that happens, you are stressing the other 3 points. You now have 4 points, out of alignment.

The flywheel housing adjusting is just as important, as any job on Building an engine. If you torque a head wrong, the metal moves, and you have a leaker. If you torque it right, it doesn't leak.

If you don't square a flywheel housing, the pilot bearing, the ball bearing in the front of the transmission case. I have seen cases destroyed from alignment problems, pressure on your rear main Babbitt, and can cause rough clutch operation. Of course, there other things that can cost you your money, but which one would you chose, one you knew about, and didn't think it was that important, or one you knew nothing about yet.

Thank's, Daren,

Herm.

[goodcar]

Originally Posted by Kohnke Rebabbitting

.003, .002, and .001 thousandths thickness. You can use old main shims, cut down, fronts, and centers, as they are .002, and .003's. McMaster-Carr carries .001, and .002 in 12" sheets.

Write down what the thickness of the finished shim pack are, right, and left, just in case, a pack would fall.

Herm.

Ace Hardware and Hobby Lobby sell brass sheets in various thickness.

[Bud]

I had to shim my crank flange because the original rebuilder did not grind it square. It was out .0020". I used a half-circle shim captured by the flywheel screws to fix the problem. It can't get out anyway. It still took quite a while to get the flywheel housing squared up, but I got there in the end.

[daren007]

Herm I follow your thinking. Just how far out would you have to be to have the problems you are talking about. If you get 9, 12, and 3 within one, two thousands you are going to have to leave it up to the clutch housing to finish the rest. You would be chasing your tail. I find it hard to believe Henry went through this procedure on any of his engines...Time is money.

[Big hammer]

Henry was working with new parts !

I've wondered about checking in the car, and a light bulb justed turned on !! Thanks Herm

........................the engine is mounted by the housing .................. Duh

[Jack Shaft]

Originally Posted by Big hammer

Henry was working with new parts !

I've wondered about checking in the car, and a light bulb justed turned on !! Thanks Herm

........................the engine is mounted by the housing .................. Duh

still can be done.easy with floatamotor's, a little harder with stock mounts..fact is if your going after clutch chatter and want to check the housing yard the engine..on heavy trucks it's way easier to pull the trans than engine...slide a jack and block under the pan,all modern stuff use a float a motor type mount.pretty common when doing a clutch..

[daren007]

Yes I realize Henry was working with new parts but I sometimes wonder if we are sciencing some things too far. Example the volume's have been written on ignition timing. Henry made it simple and it works.

[Kohnke Rebabbitting]

Originally Posted by daren007

Herm I follow your thinking. Just how far out would you have to be to have the problems you are talking about. If you get 9, 12, and 3 within one, two thousands you are going to have to leave it up to the clutch housing to finish the rest. You would be chasing your tail. I find it hard to believe Henry went through this procedure on any of his engines...Time is money.

I Agree, Daren, But Henry, had what ever he chose for a gasket thickness, a new block, flywheel housing, and a new Bell housing, and that might have came out with using the .010 shims, at that point, in time.

Ok, if you get 9 & 3, with in .002, or even Zero, that is good. But I don't care what 12 is at this time, because we are doing, only 9 & 3.

So with your 9 & 3 done, set at .002, or a new Zero, Find out what your 12, & 6 is, say the 12 is .Zero, and the 6 is 15, you have to bring the top, to match, the bottom. Now, you will add, or subtract an equal amount of shims, .003's, .002's, and .001's to make the bottom to match, the top.

So now you have 4 equal points to bolt the Bell housing to, and it is all square.

I am probably not explaining, it very well.


Herm.

[daren007]

A very good explanation. Thanks. Daren