Flywheel Housing Measurements

J

jim6346

Member
I know this one has been beat to death here, but I am at a loss, and it may be my inexperience at using a dial gauge. I was following another thread on here http://fordbarn.com/forum/showthread.php?t=72124. I bought a dial gauge with a magnetic base from Harbor Freight. However, I can not get the same reading twice. I then went and borrowed another dial gauge from a machine shop (Lufkin .0005 Gauge). Same problem (So I figure it is the user). I start from the top of the bellhousing with the dial set at .000 and rotate the crank towards the right, and I get anywhere from +.030 to +.060 (again, unless I am reading the gauge wrong). If I go to the left from the top, I get anywhere from +.03 to -.010. I have tried a variety of the brass .010 shims in different stacks, but again I can not get a consistant reading.

As a side note, I did do the other measurement to make sure the crank flange was flush and only had a variation of .001.

Any idea what I am doing wrong. Any chance the housing is warped that badly?

Thanks,
Jim
 
I'm wondering if you are getting some mis-readings from the ridges around the holes ?? I've taken a file laid nice and flat around the housing to remove any ridges that could be caused from the pulling of any threads.. I've checked this with everything still in the vehicle and just make sure I put enough forward pressure on the wheel to try and takeout any end play.. It would be easier if you're able to stand the engine on end though.. I've spent hours shimming without the results I liked and have resorted to the file..
 
With my background as a Tool and Die maker, I can't help but wonder if it would help to get the parts (FW housing) skim cut on a rotary grinder (Blanchard) The idea of parts being so far out that they must be shimmed should be unacceptable. Has this been tried?
Terry




d.j. moordigian said:
With some of the figures you gave, I got nervous. How much crank shaft end play
do you have?
Click to expand...
 
Terry said:
With my background as a Tool and Die maker, I can't help but wonder if it would help to get the parts (FW housing) skim cut on a rotary grinder (Blanchard) The idea of parts being so far out that they must be shimmed should be unacceptable. Has this been tried?
Terry
Click to expand...

Terry, they all have to be shimmed. If you would find one that didn't, it would be rare. The problem is even if the flywheel housing is flat, putting it to a block, it will not be.

It is not hard to do, but you have steps to follow, or the out come will not be what you want.
 

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When trying to make this measurement you should have the top two bolts that normally attaches the accelerator mechanisim torqued down along with the other four mounting bolts that attaches the housing to the back of the engine. To do this you need to either mount the accererator with the existing bolts, use some spacers, of use shorter bolts.

You should also have the two U-shaped .010 spacers inserted behind the two ears

You only need to measure the top 180 degrees of the clutch housing, which sould be within .006. The lower 180 degrees is pulled into alignment when the bell housing is mated up. Before you mount the bell housing you can grab the bottom of the clutch housing and move it back and forth some amount.

Tom Endy
 
90 percent of the time, a .010 thousandths shim is usless as an adjustment if you want the housing flat. If you don't make the whole housing at the 4 corners flat you will pull everything out of alignment, and that defeats what your trying to do.

You have to get the sides to read, with in at least .002 thousandths, and the top and bottom to read the same. The two top bolts will never have the same amount of shims, as they are how you get what you want for adjustment. When finished, you will have to leave it set for 24 hours, and the casting will pull, and want to adjust its self, and you may have to adjust a little, for the movement.

We use .003, .002, and .001 thousandths shims to set the housings.
 
I would like to thank everyone for their responses, they were great!! I am still trying to figure out how to stand the engine upright without damaging anything (it is already detailed up). I think once I get it up, that will probably help.

Thanks again,
Jim
 
OK, I tilted the engine down and it worked!! Got accurate readings. I ended up shimming the left ear ~.060 and the right ear .030. The left, top and right are now within .003.
Thanks everyone, now on to the flywheel......
 
jim6346 said:
OK, I tilted the engine down and it worked!! Got accurate readings. I ended up shimming the left ear ~.060 and the right ear .030. The left, top and right are now within .003.
Thanks everyone, now on to the flywheel......
Click to expand...

Man that is a lot of shim. Are the mains bored in the right place.
 
In reality the location of the flywheel housing doesn't matter ---yes it should be true, but what truing it is really doing is supposed to do is align the 2 bearing bores of the transmission with the crankshaft, as long as the end result is alignment of the transmission with the crankshaft is accomplished it doesn't matter where the flywheel housing is ---yes getting the flywheel housing true should also get the trasnsmission true but after 80 years of use what worked on the assembly line isn't a sure thing now.

When checking the flywheel the face where the clutch disc /PP needs to be checked, and the bore of the pilot bearing for runout ---when a flywheel is balanced seperate from the crankshaft it has to be mounted to the crankshaft in the same centerline as it was balanced ---if it is mounted to a different center it isn't balanced anymore
If the centerline of the trans is different than the crankshaft there is more wear and in more extreme cases popping out of 3rd, clutch hub problems, the same for a flywheel off center-
Thereis some tolerance where there is no problem, then a range of greater long term wear but no symptoms, then at extremes popping out of gear, broken parts etc.
To further complicate there are dynamic forces induced by the radius rod in the front and the torque tube from the rear ---it would be an interesting exercise to compare alignment between on the stand and in the chassis with dynamic loads.
 
jim6346 said:
OK, I tilted the engine down and it worked!! Got accurate readings. I ended up shimming the left ear ~.060 and the right ear .030. The left, top and right are now within .003.
Thanks everyone, now on to the flywheel......
Click to expand...

OK,....Now I more nervous......I'm not buying it......I think something is wrong!
What's that going to do to the paper gasket/cam plug!
 
Jim, you have to have a 4 point reading, if not you haven't done anything.

You have to get 9, and 3 o'clock the same. or at least with in 2, or3 thousandths.

When that is done 12, and 6 o'clock should read with in at least 1 thousandths of being the same, if not with 9, an 3, they should at least be with each other.

If you don't take the whole housing in to consideration, you will have problems.

You still have to leave it set 24 hours, as it can, and will change!

This part of the job is just as important, an adjusting bearings. Like Kurt said, you cant depend on the bell housing giving you any help of alignment.

One last thing, the only thing you have to adjust the housing with is the two top bolts, and it should be down to a fine amount of shims. What you have in there now, sounds a little mush, but I am not there.
 
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