As you read this article, please do not panic.  Do not pull your oil pan and look for fretting. However, when the time comes for rebuilding or a bearing change please pay close attention and look for the fretting. 

The fretting will occur on the main bearing cap where it seats to the engine block.  This is a press or interference fit and when the main bearing bolts are removed the main bearing cap should remain in the block.  If there is side clearance between the main bearing cap and the engine block the engine will have to be removed, disassembled, a new cap installed and the engine block will have to be line bored. 

On stock engines the main bearings are living as long as the engine and in many cases this is in excess of 1,000,000 miles.

Fretting will remove enough metal between the main bearing caps and the engine block to eliminate the clearance between the crankshaft and main bearings.  On N-14 engines the fretting usually occurs on number 2, 4, and 6 main bearing caps.  On M11 and ISM engines the fretting usually occurs only on number 2 and 6 main bearings.

If the main bearings are showing accelerated wear Plastigage should be used to check for bearing to crank clearance.  Anyone who has built racing engines knows what Plastigage is.  For those of you who have never heard of Plastigage, it’s a special extruded plastic thread that is used to determine the clearance in a rod or main bearing.  It’s available in various diameters.  PG-1 green must be used on the Cummins engines.  It will check the clearance from .001 to .003 inches.  The minimum clearance on a Cummins crank is .002 inches.

In order to check the clearance on number 2 main bearing you need to remove #1 and #3 caps.  Remove the lower bearing half from each cap and keep them in order.  Now you need to fabricate a shim.

To fabricate the shim, take a 1.5 in. long piece of 4” schedule 40 PVC.  That should be approximately .25 inch thick.  Now, cut the circle in half having two pieces 180 degrees in circumference.  Now cut approximately 1/8 to ¼ inch off the end of each half piece.  Place one of the plastic half pipes in number 1 and number 3 main bearing caps.  Re-install the caps into the engine and torque the main bearing bolts to only 25 ft-lbs.  This shim will hold the crankshaft up into the upper half of the main bearings.

Now remove the oil from number 2 main bearing and cap, cut a piece of Plastigage the width of the bearing laying it across the bearing 1/4 inch off of bottom dead center.  Re-install the bearing and cap then torque to 90 ft. lbs.  Then, 170 ft. lbs. and a final torque of 255 ft. lbs.  This torque is for N-14 engines built on or before November 24, 1997 and prior to engine serial number 11871545.  Be certain to coat the capscrew with engine oil to obtain the proper torque without having the bolt creek.

For N-14 engines built after November 24, 1997 and beginning with serial number 11871541, up to January 5,1998 and serial number 11875596 use the following torque specs. 90 ft lbs, 170 ft lbs and 248 ft lbs.  This series of N-14’s use a modified grade 8 bolt.  The part number is 208346.  This bolt has an orange painted head. 

For engines built on or after January 5, 1998 engine serial number 11875596, you must use a 12.9 grade bolt part number 3411337.  The torque specs are as follows:  50 ft lbs, 100 ft lbs, 140 ft lbs, then turn the bolt an additional 90 degrees.  This is called the torque plus angle method.

Now remove number 2 main bearing cap, or which ever cap your checking and measure the width of the Plastigage with the drawing on the envelope that the Plastigage came in.  If the clearance is less than .002 inches do not run the engine.  A new main bearing cap must be installed and the block line bored.  I know this must sound extremely confusing so if you’re doing this work yourself and not familiar with Plastigage invite a friend to your garage that builds racecar engines.  He knows all about Plastigage.

On the M-11 and ISM engines only Locktite 620 may be used to stop minor fretting.  The mating surfaces must be cleaned and sprayed with Locktite Primer-N and allowed to dry for 5 minutes.  The crank and main bearing saddle should be masked prior to spraying the primer.  A bead of Locktite 620 around the bolt hole and on the 45-degree bevel of the main bearing cap.  This cap must be installed within 15 minutes or the Locktite will be to dry.  The 620 Locktite adds an additional 70 percent to the shear strength of the main bearing cap joint.

Locktite and Plastigage are available at local auto parts stores.  You may have to purchase the Plastigage at a speed shop.

I have more to say however I’m out of space.  Don’t forget to remove the PVC spacer out of the other two main bearing caps and re-install the main bearings. 

Are you ready for a three day diesel truck drag racing event?  This is the first time an event of this magnitude will have taken place in the United States.  The Place:  Quaker City Dragway, Salem Ohio.  The date, August 9^th, 10^th and 11^th, 2002.  Bring your truck and your family and plan to spend all three days as a guest of Dan Swindell the new owner of Quaker City Dragway.  Dan will supply the water and electricity and you may wash your truck on his pavement.     

 Friday night will be test and tune.  Saturday night will be a diesel gamblers race and Sunday will be an all diesel drags.  This event is made possible because of the help and sponsorship of Forest Lucas of Lucas Oil Products.  Lucas Oil will be the main sponsor of the three day event.  If you have never had the opportunity to speak with Forest about lubrication you owe it to yourself to come to this event and spend a few minutes with this man.  The knowledge that you gain will stay with you the rest of your life. 

Other known sponsors will be Diesel Injection of Pittsburgh with their new Pittsburgh Power Computers.  We are looking for someone to sponsor a Saturday afternoon BBQ.  Maybe OOIDA would be interested. 

 We look forward to seeing you in August at Quaker City Dragway.  For more information call Matt at 330-332-5335.

If you’re into Peterbilts you should take a look at Warren Johnson’s new 256-page book called Peterbilt: The Evolution of Class.  L.H. Bill the founder and first president of Fageol Motors Co. laid the foundation for an enduring company when he wrote, “We will never build to a standard lower than the highest.  When we can buy better parts than we can make, we will buy them.  When we can make better parts than we can buy, we will make them. “  Bill established the evolution of class when he vowed, “We will produce the best equipment or we will produce nothing.”  The company he created in 1915 became in 1939 what is now internationally known as Peterbilt Motors Company.

Theodore Alfred “Al” Peterman was a man known for his mechanical genius.  He purchased Fageol Motors in 1939 for a total of $50,000.  The first truck to be called a Peterbilt was a chassis for Hirst Fire Truck Company.  This first completed truck was an “L” model 334 and was sold to Gannet Beckley of Stockton, CA.  The second completed truck was an “M” model 260 and was sold to Pete Bordenave also of Stockton.  If you love your “Pete” you’ll enjoy reading this book.

N-14 Cummins oil pan leakage.

 Do you remember the old aluminum oil pans on the small cam engines that would leak engine oil due to cracks around the rear corners?  Weekly we would weld and reinforce these pans to stop the oil leak.  Then the stamped steel oil pan was released in 1981 and our oil leaking problems were over.  So we thought.  Because of the amount of engine noise emitted from the oil pan Cummins developed an insulation blanket to cover the pan.  However, the insulation would retain moisture and sometimes develop rust that would eventually eat through the oil pan.  A quick and inexpensive repair is to thoroughly sand or grind the rust and paint from the oil pan in a 6-inch diameter.  Thoroughly clean the bare metal with brake clean or lacquer thinner to remove any dust or oil.  The next step is to purchase a Swiss fiberglass repair kit from the local auto parts store.  Using the angel hair matting, not the fiberglass cloth, mix the resin and hardener according to the directions on the can.  You must do this in a heated garage.  Fiberglass needs heat to cure.  Using a flux brush apply a coating of resin to the oil pan then a piece of angel hair matting about 1” larger than the rust hole, then more resin, tapping it into the angel hair using the flux brush.  Then another piece of angel hair matting 1” larger than the first piece along with more resin.  Continue this process until you have applied about 5 layers of angel hair matting.  Make sure there are no air pockets between the layers.  Allow to harden for several hours before installing the oil pan to the engine.  That is a $20.00 oil pan hole repair.  If the metal is properly prepared the fiberglass patch will never come off.

The N-14 rear sump stamped steel oil pan will sometimes crack around the rear corner bolts.  To eliminate this problem Cummins manufactures a clamping plate part number 4626248.  This plate mounts to the rear six bolts below the oil pan.  This clamping plate requires four part number 4026354 and 2 part number 4026355 bolts.  If your engine is equipped with the insulation cover you need 2 of part number 4058673 bolts.

Engines produced on December 7^th 1999 and later beginning with serial number 11988415 without the noise insulation cover already have this clamping plate installed.  If your engine has the insulation cover and was produced on March 20^th, 2000 or later and beginning with serial number 12002401, it also is equipped with the clamping plate.

This is an economic way to avoid a cracked oil pan which could become a costly repair.  Do not over-tighten the oil pan bolts.  The four 5/16 inch bolts located at the rear of the pan are torqued to 20 ft. lbs and the thirty two 7/16 inch bolts are torqued to 50 ft. lbs.