Go Back   The Ford Barn > General Discussion > Model A (1928-31)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 05-11-2017, 09:02 AM   #1
Dave1931Pickup
Senior Member
 
Join Date: Jun 2015
Posts: 167
Default Flywheel Housing Alignment

I just checked the flywheel housing alignment to the crankshaft flange using a dial indicator as described in the service bulletins. Engine is a complete rebuild with a new Burlington crankshaft. Engine is mounted in bare frame with new rear engine mount rubber pads. Everything is bolted and torqued tight. New gasket and brass shims between the two upper bolts where the gas pedal assembly attaches. The flywheel housing was checked for flat on a surface plate and dial indicator. The entire surface was within .003.
When sweeping the dial indicator by turning the crank everything is within .005 until it gets to the top portion where the shims are and the the dial jumps to .015. The service bulletin said to "add" the brass shims if the housing is not within .006 in relation to the crank flange. My thoughts are to remove the brass shims even though they are meant to compensate for the thickness of the gasket.
Thought and advise please.
Dave1931Pickup is offline   Reply With Quote
Old 05-11-2017, 09:11 AM   #2
Patrick L.
Senior Member
 
Patrick L.'s Avatar
 
Join Date: May 2010
Location: Largo Florida
Posts: 7,225
Default Re: Flywheel Housing Alignment

So, you haven't tried it without the shims. I would just to see what it has to say. If its good without them, then I would stick everything together and run it.

I think the closest I could get mine was .009", but, it seems fine.
Patrick L. is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 05-11-2017, 09:12 AM   #3
katy
Senior Member
 
katy's Avatar
 
Join Date: Jun 2015
Location: Red Deer, Alberta
Posts: 5,011
Default Re: Flywheel Housing Alignment

If removing the shims corrects the problem go for it. Maybe the gasket you used is thinner than stock?
__________________
If you don't hear a rumor by 10 AM, start one!.
Got my education out behind the barn!
katy is offline   Reply With Quote
Old 05-11-2017, 09:24 AM   #4
Jerry in Shasta
Senior Member
 
Jerry in Shasta's Avatar
 
Join Date: Jun 2010
Location: (Old)Shasta (Redding) CA
Posts: 385
Default Re: Flywheel Housing Alignment

Over the years I have had a number of engines in and out of my cars. I did not know for years that the cover needed to be checked. Needles to say it was never checked.

I never noticed a clutch type problem

I later figured that you also must check the clutch cover because it it was not true it would easily pull the flywheel cover back out of alignment.
__________________
Connoisseur of Rust
Jerry in Shasta is online now   Reply With Quote
Old 05-11-2017, 09:35 AM   #5
Joe K
Senior Member
 
Joe K's Avatar
 
Join Date: Jul 2010
Location: Cow Hampshire
Posts: 4,175
Default Re: Flywheel Housing Alignment

Quote:
Originally Posted by Jerry in Shasta View Post
I later figured that you also must check the clutch cover because it it was not true it would easily pull the flywheel cover back out of alignment.
This is true. It takes two to tango. And given that the bellhousing is a lot thinner materials and pierced by the access hole, it probably has a lot more give - and possibility of uncertain dimension - than the rather stout by comparison flywheel housing.

Now should you ignore the tabs and shims on the FWH to block junction? Probably not. But get it within 0.012 (my measure and best effort) then it is probably ok.

How about the radial cracks on the flywheel housing? I have seen Model A that obviously went MANY years in the cracked condition. So even though cracks are not a deal killer (obviously) I strive to replace a cracked flywheel housing. But one wonders if a misalignment previous (lack of support?) CAUSED the cracks.

Joe K
__________________
Shudda kept the horse.
Joe K is offline   Reply With Quote
Old 05-11-2017, 09:53 AM   #6
Dave in MN
Senior Member
 
Dave in MN's Avatar
 
Join Date: May 2010
Location: Jordan, MN
Posts: 1,410
Default Re: Flywheel Housing Alignment

Sponsored Links (Register now to hide all advertisements)
Dave,
With the engine mounted in the frame you may not get a good reading as the endplay between the crankshaft and the block may add to the measurements you are taking. Most of us, that work on engines, check this alignment with the engine mounted in an engine stand with the front end of the engine pointing straight down. The weight of the crankshaft, keeps the rear thrust surfaces in contact to allow for a consistent crankshaft position as it is rotated.
Good day!
Dave in MN is offline   Reply With Quote
Old 05-11-2017, 10:16 AM   #7
George Miller
Senior Member
 
George Miller's Avatar
 
Join Date: May 2010
Location: NC
Posts: 2,975
Default Re: Flywheel Housing Alignment

Quote:
Originally Posted by Dave in MN View Post
Dave,
With the engine mounted in the frame you may not get a good reading as the endplay between the crankshaft and the block may add to the measurements you are taking. Most of us, that work on engines, check this alignment with the engine mounted in an engine stand with the front end of the engine pointing straight down. The weight of the crankshaft, keeps the rear thrust surfaces in contact to allow for a consistent crankshaft position as it is rotated.
Good day!
Plus 1
George Miller is offline   Reply With Quote
Old 05-11-2017, 11:47 AM   #8
1930 coupe
Senior Member
 
Join Date: May 2010
Posts: 226
Default Re: Flywheel Housing Alignment

I also agree with the end play issue, and point the engine down.
I only check at 9-12-3 o'clock because the housing is very flexible and you can put the indicator at 6 o'clock and push or pull on the housing and the indicator will move .005" - .010". When the bell housing is bolted to the housing, the 6 o'clock position will move to line up with the bell housing.
Attached Images
File Type: jpg indicator 01.jpg (172.4 KB, 93 views)
File Type: jpg indicator 02.jpg (185.9 KB, 81 views)
1930 coupe is offline   Reply With Quote
Old 05-11-2017, 12:01 PM   #9
Tom Endy
Senior Member
 
Tom Endy's Avatar
 
Join Date: May 2010
Location: Southern California
Posts: 3,122
Default Re: Flywheel Housing Alignment

Quote:
Originally Posted by Dave1931Pickup View Post
I just checked the flywheel housing alignment to the crankshaft flange using a dial indicator as described in the service bulletins. Engine is a complete rebuild with a new Burlington crankshaft. Engine is mounted in bare frame with new rear engine mount rubber pads. Everything is bolted and torqued tight. New gasket and brass shims between the two upper bolts where the gas pedal assembly attaches. The flywheel housing was checked for flat on a surface plate and dial indicator. The entire surface was within .003.
When sweeping the dial indicator by turning the crank everything is within .005 until it gets to the top portion where the shims are and the the dial jumps to .015. The service bulletin said to "add" the brass shims if the housing is not within .006 in relation to the crank flange. My thoughts are to remove the brass shims even though they are meant to compensate for the thickness of the gasket.
Thought and advise please.

You must have the two top mounting bolts torqued down to make the test. These are the bolts that hold the throttle linkage on. Likely you have the linkage off. In this case the bolts would be too long to torque. I keep a pair of shorter bolts handy that I use to tighten the top during the test.

When making the test you must keep in mind that the two .010 metal shims are for the purpose of being even with the paper gasket that is at the lower mounting bolts when all is torqued down. The suppliers sell gaskets that are all over the map in thickness. Most are all too thin. The paper gasket will crush down some, the metal shims will not. What I do is purchase a roll of gasket material from Napa and cut my own. You can buy various thicknesses. I purchase the gasket material thicker than the shims. Usually .015 - .016.

Tom Endy
Tom Endy is offline   Reply With Quote
Old 05-11-2017, 10:04 PM   #10
Kohnke Rebabbitting
Senior Member
 
Join Date: May 2010
Location: 60615,330th Ave.,Clare, Iowa, 50524
Posts: 1,457
Default Re: Flywheel Housing Alignment

The way we have always done it is get 9 and 3 to read the same or with in maybe .002, plus, or minus zero. This is done by putting an UNEQUAL amount of shims under the two top ears most of the time. Then, get 12, and 6 to read the same, even if they are not the same readings as 9 and 3 position, leave it for 24 hours as most of the time the cast housing will warp to what ever tension it is under, and then check again, and reset if needed.

When 9 and 3 are being set, you add, or remove from the two ears, right or left to get same readings.

When 12 and 6 are being set, you have to add, or remove an equal amount of shims on both ears to get the top and bottom to match.

The only thing a .010 shim is good for is to fill up big gaps, that is all. There is no way that you can set a housing perfect with them, unless you just lucked out.

The flywheel housing is one of the most important settings there is, do not take this lightly!

The shims we use are .003, .002, and .001, with out using them, you can only get close, not perfect.

So, by getting the 9 and 3 position to read the same, and top an bottom, 12, and 6 to read the same, Even if the 12 and 6 readings are not the same as the side to side.

So now what you have is 4 square points to bolt a Transmission to.

Works every time!

An out of align pilot shaft, will wear a rear main, cause bad clutch action, take out pilot bearing, ect.

Also, your rear flange has to be ground to the cranks center line. If you are note square, your wasting your time.


Herm.
Kohnke Rebabbitting is offline   Reply With Quote
Old 05-12-2017, 09:49 AM   #11
Dave1931Pickup
Senior Member
 
Join Date: Jun 2015
Posts: 167
Default Re: Flywheel Housing Alignment

Thanks to every ones information. I do understand the reason for aligning the flywheel housing. I'm sure that doing the alignment in an engine stand can produce very precise results. But what happens to the alignment when the engine assembly is bolted into the frame and all of the external forces start pushing and pulling on it during normal driving conditions? Does it stay in perfect alignment? If you can influence the dial indicator reading by pushing on the housing when on an engine stand what happens to the housing when driving over that bumpy road? I have worked with metal all of my life and believe me it flexes and moves. I will bet the flywheel housing does the same thing when driving.

Just my thoughts about the real world versus a static "perfect" world.
Dave1931Pickup is offline   Reply With Quote
Old 05-12-2017, 11:21 AM   #12
Dave in MN
Senior Member
 
Dave in MN's Avatar
 
Join Date: May 2010
Location: Jordan, MN
Posts: 1,410
Default Re: Flywheel Housing Alignment

Dave,
At this point, figure out some way to hold a consistent and constant pressure against the flywheel flange while taking your readings. Work in Herm's techniques and you will be okay.

I suppose the flywheel housing will move some when in use but the point we all are making is that proper initial alignment is an important step in making sure the transmission stays in gear and all the adjoining components have a long life. Once you install the bellhousing to the flywheel housing, there is no way I know of to properly align the housing. This alignment step must be done "static".
Good Day!
Dave in MN is offline   Reply With Quote
Old 05-12-2017, 12:34 PM   #13
Tom Wesenberg
Senior Member
 
Tom Wesenberg's Avatar
 
Join Date: May 2010
Location: Mpls, MN
Posts: 27,582
Default Re: Flywheel Housing Alignment

Yes, the clutch housing will pull the flywheel housing to conform with it, but the whole point is to get the tranny input shaft centerline into exact alignment with the crankshaft centerline.

As mentioned, be sure the two ears are bolted tight and make sure the crankshaft endplay isn't throwing off your measurements. I've done the checks in the frame, but I always press the crank forward as I rotate it to be sure the endplay is always in the same direction.

I had to add a couple extra shims to one ear on the least one I did to get the 9, 12, and 3 positions all within .006".
Tom Wesenberg is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 05:31 PM.