Model A Ford Club of America
Sacramento, California Chapter

Main Bearing Clearances

This is an excerpt from an article titled "Measuring and adjusting main bearing and rod bearing clearances" written by Warren Rugenstein of Kansas City, MO. It was published in “How to Restore your Model A – Volume 6”.

The recommended oil clearance for Model A Ford main and rod bearings is .001”, (one thousandth of an inch). Through normal use of the car, the soft Babbitt bearings slowly wear away and the clearance widens. If unattended, the clearance can become so wide that improper lubrication and hammering will occur. Serious Damage to the crakeshaft is the result.
Adjusting the clearance is fairly simple. In addition to removing everything that was necessary just to get to the bearings, I removed my exhaust and intake manifolds. The extra room to work was useful. If possible, having a helper will be handy, but you can do it by yourself.

Click the link below to read the full article.