Bearing clearances

[Magoo2]

I've dropped the pan. Found some chunks. I'm about at the limit of my knowledge. Can anyone tell me how to check the clearances on the connecting rods and crankshaft with the engine still in the car?

[J Franklin]

Buy some Plastigauge at the local auto parts store with a range that includes 1.5 thousandths. Follow the instructions on the package. I like to remove shims equally from both sides if needed. I would start with the center main as it seems to wear the most, if it is within tolerance most likely the other 2 are also unless the babbitt is destroyed as you said you saw some chunks

[Patrick L.]

You'll be spending a far amount of time laying on your back with oil dripping in your face. But, if the bearings are in good shape this may be the only time you'll have to do it.

As J mentioned get some .001'-.003" plastigauge. I use a jack to apply slight upward tension on the crank when checking the center main. And I too prefer to keep the shim stack the same thickness on each side.

The center main tends to wear the most with the rear being the next worn. I like to set the clearance at .0015" for all [ main and rod] and a bit tighter for the rear main.

Take your time and you'll get it done along with some creative language.

[Mikeinnj]

Be aware that you have to undo the main bearing caps, some of witch require a special socket. They can be tough for an old timer to bust loose. There have been many articles written on this forum and in the Model A Ford repair manuals. You can perform a search on this forum by using that feature at the top of this page.

[Patrick L.]

Sponsored Links (Register now to hide all advertisements)

Originally Posted by Mikeinnj

Be aware that you have to undo the main bearing caps, some of witch require a special socket. They can be tough for an old timer to bust loose. There have been many articles written on this forum and in the Model A Ford repair manuals. You can perform a search on this forum by using that feature at the top of this page.

' witch ' ? Well, yep, some can be a son-of-a witch to get out.

If I remember right, I think the 'tonnage' for the mains is 80# and rods 35# or there about.