When to reshim

[Floats]

Hi Guys,
When and how often should the mains and rods be reshimed? I have had my car for about two years. I have no history and do not know when, if or wether the engine was rebuilt. She runs a fine, although a little noisy. Dont ask me where the noise is from, top or bottom, inside or outside.
Would you suggest I leave well alone OR drop the pan and re shim.

[J Franklin]

If you have never dropped the pan for a look go ahead and do it. it's easy and you can check the condition of the bearings and clean out the sludge. The rods can be checked easily and then at least check the center main as it wears soonest. Don't pull shims unless you find things too loose.

[Pinesdune]

If you do decide to check the mains clearances, just a note, use a small hydraulic jack to apply a tiny bit of pressure to "lift" the crank, if all the main bearings are loose (even by a few thousandths) when you tighten the cap with the plasti-guage, the plastiguage will take the weight of the crank rather than just squish in the space. IE it'll look like your tolerances are tighter than they really are.


Looking for the front bumper emblem that has "Ford, Made In Canada"

[Jim Brierley]

Good advice by Pinesdune! Choose a nice Spring day and enjoy the process.

[J Franklin]

Pump some grease and gear oil in, it will mix up while driving.

[George Miller]

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I say leave it alone.

[CarlG]

Originally Posted by J Franklin

Pump some grease and gear oil in, it will mix up while driving.

Why would you want that in your crankcase?

[J Franklin]

Oops!!! that landed on the wrong thread, was an answer to U-joint question. Of course it would quiet the noise in his engine for a while!

[Dave in MN]

Given you do not know when the bearings were last checked or adjusted and that you say it is a bit noisy, I understand your concern as to what to do. I would look for a local Model A owner or two that have some experience in knowing what a good engine should sound like. Get one or two opinions and then decide what to do. I work on engines, so it is easy for me to say drop the pan and check the bearings but it is a bit of work. Knowing the condition of the engine is important if you plan to drive much or venture far from home.
Good Day!

[Tom Wesenberg]

I agree with Dave. It's much easier to spend the time now, rather than on the side of the road.

[Patrick L.]

If you do decide to do it, just take your time and not rush it.

The slight pressure from the hydraulic is the thing to do.

Some folks like the aluminum foil method. I prefer plastigauge and setting them at .0015".

Pulling the caps will let you know what you have to work with, what shape the bearings are in.

[redmodelt]

RE "Some folks like the aluminum foil method" after fighting plastigauge working under the car I went to aluminum foil and never looked back.

[Mike V. Florida]

Originally Posted by redmodelt

RE "Some folks like the aluminum foil method" after fighting plastigauge working under the car I went to aluminum foil and never looked back.

Ditto,

INTERFERENCE FITTING OF BEARINGS
Mike Flanagan had posted his description of interference fitting of the main bearings in the Model A engine. Because of the weight of the flywheel and the flexibility of the Model A crank, plastigauge my not be a reliable method of adjusting the bearing clearances with the engine in the car.
Here's Mike:
How do you check the clearance on the bearings? It is not QED but can be done if you can lay on your back and work with oil and grit and grime falling in your eyes.
First you gotta drop the pan, let it sit overnight to get all the oil that will fall out to do so. You are still going to get oily. Pull the damn oil pump out and lay it aside. You can shine a flashlight up in there to see which way the tang is oriented to reinstall and with it out there won't be so damn much blood on it to clean off it.
Then I start with the center main. This one requires that the valve cover be taken off as the nut is in side there. The other nut is between 2 and three outside on the other side. Remove the cap being careful to keep the shims on the same side as they came from. Visually inspect the bearing for cracks and places at both the front and back that look as if it has been compressing the babbitt and pushing it forward or to the rear. Bad signs if so. To check the clearance, use a piece of aluminum foil .002 thick. The heavy duty she buys to do heavy-duty things is .002 but the regular like you cook a baked potato in is .001 so you fold it. You want a piece as long as the cap and about 1/2 wide. Lay this in the cap and with the SHIMS BACK IN THERE put the cap
back on and tighten it up. Now you want to see if the motor will turn with the obstruction in place. Stick a 6" punch in one of the balance holes in the crank throw so the pull will be consistent each time you check. You are looking for lockup with the obstruction in there and free without. The shims are increments of .002 or .003 depending on which the rebuild used.
The steel shims are generally in .002 and the brass in .003. Peel 1 increment from one side at a time, one from one side and if that doesn't lock it up then do one from the other side. Yes it tedious; just be glad you didn't by a space shuttle. Once you get this bearing to lockup then remove the obstruction and replace it and tighten it up again and see if it will rotate. If it won't
turn with the 6" punch then put that dame shim back in and run it another 3k.
Do the rear next then the front. The rods adjust exactly the same way. When you finally get a bearing adjusted like you want it put some pre-lube (engine assembly lube) on there before
putting it on there for the last time. Torque to whatever you has been using (75 minimum) and go. The rod nuts torque to 40.
To put the pan on there install the oil pump using a 3/8 fine thread bolt in the plug hole in the side of the block to retain the pump while you install the pan. Finger tight as the threads are actually national pipe threads but the bolt will work in there. Get some 5/16 all thread and make yourself some cheaters by cutting 4 pieces 4 or 5 inches long. Screw them into the pan rail and
let 'em hang down. Slip the pan over them and start a nut. Then it is a matter of tightening the nuts incrementally in turn and thereby winching the pan up against the spring on the pump.
The gaskets and sealer is a matter of choice but my opinion is that the silicone belongs in the bathroom. I use permatex red personally. When you put it all back together put some of the oil down the dist hole so the valve galley is oiled. It should not have lost any oil but I like to make sure.
Lotta work laying on your back

[Floats]

Thank you very much gents, your advice is much appreciated.

[Terry, NJ]

Look, There are lots of things in an engine that will make noise besides loose rods. Wrist pin knocks, piston slap, carbon knocks, excessive valve clearances, etc, just about every part will make noise. I would take the valve cover off and check the valve clearances before I took the oil pan off. First rule of troubleshooting, check the $.50 fuse before you go for the $1000 wiring. Check the gas tank and see if there's any gas! Do the easy stuff first!
Terry

[Domino]

If it ain't broke - don't fix it - because then it may become broke (don't ask how I know). Drive and enjoy it.

[J Franklin]

"If it ain't broke - don't fix it - because then it may become broke" might work, but neglect will always hurt your car. find out what and where the noise is coming from and address or ignore it.

[duke36]

We have access to a car lift to do bearings, pull the pan, etc.. Any suggestions on how to apply the pressure to the crank? Would a piece of wood across the lift support a bottle jack and should the jack be placed as close to the bearing in question or does that matter?

[Pinesdune]

Yes it should be enough, you just need enough pressure to support the weight of the crank while you measure the clearances, and yes, try to get it close to the bearing being measured as it can make a difference, tho a very slight one


Looking for the front bumper emblem that has "Ford, Made In Canada"

[Floats]

OK Gents,
Thanks for your advice.
The consensus is,
ON THE ONE HAND
Don't fix if it aint broke.

ON THE OTHER HAND
1. Determine where the noise is coming from, have a look
2. No history, have a look
3. 20,000 miles, have look and adjust

I might have found someone who knows the history, I'll share once I manage to get hold of the guy.