FlywhIeel housing

[jhowes]

I have a flywheel housing that is way out of tolerance. I measured from the crank shaft flange around the housing and the measurements were over 30 thousands off. I found that the .010 shims were not behind the ears where the gas mechanism bolts on to there back of the block. I then placed the .010 shims in place which improved the situation but it is still out of specification.
Question
1. Can I put two .010 shims behind those ears instead of just the one?
2. Behind the four mounting bolts, can I put .005 to.010 shims as needed in addition to the doubled up .010 shims behind the two ears?

I don't want to put to much strain on the housing but still have the runout measure within .005".
Any thoughts or suggestions appreciated.
Jack

[BRENT in 10-uh-C]

Jack, it sounds like the housing needs to be machined.

[Patrick L.]

I don't like using extra shims. So I have filed the covers to get them as close as I can. [ One from .034" down to .008"]

Brent is right, the 'more better' way would be to send it out for machining.

[jhowes]

Thanks to both Brent and Patrick. It may not be what I wanted to hear but good advice. Jack

[Dave in MN]

Try varying the amount of shim you place under the gas mech. ears and tighten the bolts through these ears before each alignment check. More or less from the base amount of .010" under these ears will usually bring all but the worst flywheel housings to within .006" (at 9:00, Noon and 3:00). Disregard your reading at 6:00 as the bellhousing will typically move this area as required.
If not, then machine it as Brent says.
Good Day!

[37 Coupe]

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Re you sure it is not cracked? I just dealt with one that was way off also and I swore it wasn.t cracked at least at normal places on the mounting surface.It was however cracked at the circumference at the two top mountinf ears all the way to and through starter mounting face. Showed up after degreasing.

[jhowes]

Good to hear, Thanks Dave. I filed some and gained .002". Tomorrow will tell the results as I shim and measure . Jack

[Dave in MN]

Originally Posted by jhowes

Good to hear, Thanks Dave. I filed some and gained .002". Tomorrow will tell the results as I shim and measure . Jack

Let us know what you did and then the results. Good info for every one that is tuned in. Thanks,
Dave

[jw hash]

keep In mind the thickness of the gasket. the original gasket are very thin, and some reproduction gaskets are thicker. it makes a big difference on how many shims you have to add to make up for the thicker gasket.

[Kohnke Rebabbitting]

Surfacing a flywheel housing does little good, The repro ones are surfaced, and from what I found are off greater then any original. I have never had to give up on any housing, and say it cant be done. It is very easy.

First, you have to have a crank flange that is ground true to the center line of the crank, and make sure the flange rear, is 90 degree to the main, and is 100% Flat.

There are only two adjustments. 9 and 3, and 12, and 6.

Do 9 and 3 always first. I like the thick gaskets best, and won't go into to it now. The top two ears, when done, will have two different amounts of shims in them. The only thing that .010 thousandths shims are good for, is filling a large gap. My final adjustments are always down to .001 thousandths. Get your 9 & 3 to Plus, or minus, with in 3, or 4 thousandths. I will show some of Daves pictures.

Next, you are ready for the 12, and 6 position. It does not matter what the sides are, compared to the top and bottom. What you are after is FOUR SQUARE POINTS to bolt the Bell housing to, so the pilot shaft, clutch, ect., run true. When adding, and subtracting shims now, you have to use equal amounts, in shim thickness.
So bring the top, normally out to match what the bottom is, and your done.

Herm.

[jhowes]

Herm; Why do your notes say "leave 24 hours"?

[37 Coupe]

I noticed that it looks like you paint the machined face of the flywheel or at least it looks green? Also on the block it looks like the intake and exhaust port surfaces are painted.I guess this is what I have been wondering to paint or paint around the gasket area.

[Kohnke Rebabbitting]

Originally Posted by jhowes

Herm; Why do your notes say "leave 24 hours"?

We leave the cast iron housing 24 hours, as they can, and do sometimes warp, and then you have to readjust the shims, and in that case we leave another 24 hours. Getting that housing square, is very important to wear, and vibration.

Herm.

[30 Closed Cab PU]

Originally Posted by 37 Coupe

I noticed that it looks like you paint the machined face of the flywheel or at least it looks green? Also on the block it looks like the intake and exhaust port surfaces are painted.I guess this is what I have been wondering to paint or paint around the gasket area.

Thought I read on the Barn or somewhere to not have a completely smooth gasket mating surfaces, smooth surfaces do not seal as well?

[Kohnke Rebabbitting]

Originally Posted by 37 Coupe

I noticed that it looks like you paint the machined face of the flywheel or at least it looks green? Also on the block it looks like the intake and exhaust port surfaces are painted.I guess this is what I have been wondering to paint or paint around the gasket area.

Yes, I normally paint all paintable surfaces. I had a reason for not painting the inside of the flywheel housing, at the time, can't remember right now. Most insides are covered with oil anyway.

Herm.

[37 Coupe]

Originally Posted by 30 Closed Cab PU

Thought I read on the Barn or somewhere to not have a completely smooth gasket mating surfaces, smooth surfaces do not seal as well?

I have never heard that before.Theoretically I think two mating surfaces in a perfect world would depend less on a gasket not more to seal.

[30 Closed Cab PU]

Just thought I would mention it, if more experienced Barner's don't agree, definitely believe them. Since Kohnke paints, it must be OK. Wanted to see if my understanding is right or wrong or doesn't matter.

[Bob C]

Originally Posted by 30 Closed Cab PU

Thought I read on the Barn or somewhere to not have a completely smooth gasket mating surfaces, smooth surfaces do not seal as well?

I think this applies mostly to the head gasket, see the link.
https://www.felpro.com/technical/tec...ce-finish.html


Bob

[30 Closed Cab PU]

Originally Posted by Bob C

I think this applies mostly to the head gasket, see the link.
https://www.felpro.com/technical/tec...ce-finish.html


Bob

Thanks Bob. Makes sense to me now, not important for sealing with little or no pressures involved like pan gaskets, transmission, diff, etc. With Head that has compression stroke and combustion pressures, helps hold the gasket from moving.

[Kohnke Rebabbitting]

Originally Posted by 30 Closed Cab PU

Thought I read on the Barn or somewhere to not have a completely smooth gasket mating surfaces, smooth surfaces do not seal as well?

The only thing I have noticed is, to thin of gasket, which some times will put you to close to the block, to be able to use the right amount of shims. Also not using Indian Head gasket cement, and get seepage, at the end of the cam.

Herm.