There are Worse Things Than Dirt Under Your Fingernails
by **** Zakrzewski ©2000-2002
The greatest enemy of a bearing is dirt! It will significantly shorten the life of all types of bearings.
Dirt in engines
There are two kinds of dirt that can find its way into your engine?metallic and non-metallic. Metallic dirt can be further broken down into ferrous and non-ferrous particles. Ferris particles are cast iron and steel while non-ferrous particles are aluminum, brass and babbitt from bearing inserts. Non-metallic dirt can be traces of grit from the cylinder honing process or the blasting process used to clean the outside of the block before painting or powder-coating.
Metallic dirt is created when machining work is done to blue-print a block, during the break-in of a new or rebuilt motor, and slowly over time as metallic components like cam lobes, lifters, rings, cylinder walls, timing chains and sprockets experience normal wear. During break-in the greatest amount of dirt (ferrous metallic) can be created when new piston rings knock peaks off the surface of newly honed cylinder walls. See Figure #1.
Figure #1
Note: You can minimize the amount of ferrous metallic dirt created at break-in by following the ring manufacturers recommendation for honing the cylinder walls and applying the appropriate assembly lubricant to critical bearing surfaces at assembly.
To remove metallic and non-metallic particles from an engine block before assembly, clean the block thoroughly by scrubbing every inch, including oil galleys, with hot soapy water. Then perform a high-pressure rinse. After the rinse, immediately spray the entire block with WD-40 to prevent rusting. Remember that engine blocks returned to you after machining and honing are NOT adequately cleaned!
Despite all your best efforts, there will be some metallic and non-metallic particles that remain in the system after assembly and some metallic dirt will be generated during normal operation. To remove the potential for harm that can be caused by these particles, I suggest two things:
1. An old racer's trick is to epoxy five or six small permanent magnets in the bottom of your oil pan, being careful NOT to locate them directly under the oil pump pick-up screen. See Photo #1. These magnets will pick up the majority of ferrous metallic particles for several years. The ideal magnets are readily available at you local Radio Shack store at a cost of $1.79 for a pack of 5 (Cat. No. 64-1888). Note: A magnetic oil pan drain plug is NOT an equivalent solution since it isn't on the bottom of the pan doesn't offer near the effective surface area.
Photo #1
2. Plug the by-pass in your oil filter adapter forcing all circulating oil through the filter before it is delivered to any bearing surface. See Photo
Photo #2
#2. This process will capture all remaining metallic and non-metallic particles within the micron capability of your filter. With this modification you MUST locate the oil pressure sending unit after the oil filter. I have found this to be a very controversial idea, but have been making the modification since 1973 with no problems whatsoever.
I like to monitor for dirt in my lubrication system by cutting my used oil filters open to see what metallic and/or non-metallic dirt my filter has trapped. The type of dirt you find will help you diagnose what's going on inside your engine; i.e., which components are wearing. This analysis will be the subject of a future article. A large amount of metallic dirt would be an indication very rapid wear and emanate engine/bearing failure.
Note: Don't cut your filter apart with a hacksaw. You won't be able to separate saw chips from the engine dirt. I suggest you use a filter cutter part #910-81031 available from Speedway for $39.95.
Dirt in front wheel bearings
Dirt in wheel bearings is non-metallic road grit or brake dust that has entered the bearing because of a worn seal, or it could be metallic particles that were left in the bearing housing the last time you had the rotors turned.
My recommendation for wheel bearing maintenance is to clean and inspect the bearings each time you replace brake shoes or pads. You should have the rotors turned at this time also. If the bearing shows signs of wear, replace it with a new inner and outer race. Pack each bearing with a good quality high pressure grease and install new seals.
Warning: I have noticed that some after-market rotors with an integral bearing housing are probably being sourced from China and have very poorly machined bearing seats for outer bearing races. These bearing seats can be rough, tapered, out of round and can lack concentricity between the inner and outer seats. These rotors must be replaced with good quality rotors to prevent premature bearing failure and wheel wobble.
I have also noticed the seal surface of some after-market wheel spindles aren't smooth enough, and the inboard seals are being chewed up in as little as 1,000 miles! If you find this to be the case then polish the seal surface on the spindle with fine emery paper until it has a bright appearance (the smoother the better). Replace the seal, and be sure to lubricate the rubbing surface of the seal with bearing grease at assembly.
Dirt in automatic transmissions
Dirt in automatic transmissions is non-metallic dirt from clutch disks and metallic (steel/cast iron and aluminum) dirt from normal metal parts wear.
My recommendation for metallic dirt is once again to use the old racer's trick of placing four or five permanent magnets from Radio Shack in the oil pan of the transmission. Again, be careful NOT to locate the magnets directly under the oil pump pick-up screen. The non-metallic friction material and aluminum is best addressed by changing the oil and filter in the transmission every 50,000 miles. Change more often if the transmission sees severe duty. When changing oil, I suggest the "converter and cooler flushing method" described on pages 14 and 15 in Ron Sessions Turbo Hydra-Matic 350 Handbook.
Dirt in manual transmissions and differentials
With the exception of broken gear teeth, you should never have any problems with a manual transmission or differential. They are basically sealed units and the systems themselves create very little metallic dirt. Just make sure you thoroughly clean any blasting grit from inside the housing, which may be left from cleaning the outside of the housing prior to painting or powder-coating. Believe me, this is not an easy job! There are still lots of places for grit to hide.
**** Z
http://www.streetrodstuff.com
**** Z - CEO
Streetrod Stuff, Inc.
by **** Zakrzewski ©2000-2002
The greatest enemy of a bearing is dirt! It will significantly shorten the life of all types of bearings.
Dirt in engines
There are two kinds of dirt that can find its way into your engine?metallic and non-metallic. Metallic dirt can be further broken down into ferrous and non-ferrous particles. Ferris particles are cast iron and steel while non-ferrous particles are aluminum, brass and babbitt from bearing inserts. Non-metallic dirt can be traces of grit from the cylinder honing process or the blasting process used to clean the outside of the block before painting or powder-coating.
Metallic dirt is created when machining work is done to blue-print a block, during the break-in of a new or rebuilt motor, and slowly over time as metallic components like cam lobes, lifters, rings, cylinder walls, timing chains and sprockets experience normal wear. During break-in the greatest amount of dirt (ferrous metallic) can be created when new piston rings knock peaks off the surface of newly honed cylinder walls. See Figure #1.
Figure #1
Note: You can minimize the amount of ferrous metallic dirt created at break-in by following the ring manufacturers recommendation for honing the cylinder walls and applying the appropriate assembly lubricant to critical bearing surfaces at assembly.
To remove metallic and non-metallic particles from an engine block before assembly, clean the block thoroughly by scrubbing every inch, including oil galleys, with hot soapy water. Then perform a high-pressure rinse. After the rinse, immediately spray the entire block with WD-40 to prevent rusting. Remember that engine blocks returned to you after machining and honing are NOT adequately cleaned!
Despite all your best efforts, there will be some metallic and non-metallic particles that remain in the system after assembly and some metallic dirt will be generated during normal operation. To remove the potential for harm that can be caused by these particles, I suggest two things:
1. An old racer's trick is to epoxy five or six small permanent magnets in the bottom of your oil pan, being careful NOT to locate them directly under the oil pump pick-up screen. See Photo #1. These magnets will pick up the majority of ferrous metallic particles for several years. The ideal magnets are readily available at you local Radio Shack store at a cost of $1.79 for a pack of 5 (Cat. No. 64-1888). Note: A magnetic oil pan drain plug is NOT an equivalent solution since it isn't on the bottom of the pan doesn't offer near the effective surface area.
Photo #1
2. Plug the by-pass in your oil filter adapter forcing all circulating oil through the filter before it is delivered to any bearing surface. See Photo
Photo #2
#2. This process will capture all remaining metallic and non-metallic particles within the micron capability of your filter. With this modification you MUST locate the oil pressure sending unit after the oil filter. I have found this to be a very controversial idea, but have been making the modification since 1973 with no problems whatsoever.
I like to monitor for dirt in my lubrication system by cutting my used oil filters open to see what metallic and/or non-metallic dirt my filter has trapped. The type of dirt you find will help you diagnose what's going on inside your engine; i.e., which components are wearing. This analysis will be the subject of a future article. A large amount of metallic dirt would be an indication very rapid wear and emanate engine/bearing failure.
Note: Don't cut your filter apart with a hacksaw. You won't be able to separate saw chips from the engine dirt. I suggest you use a filter cutter part #910-81031 available from Speedway for $39.95.
Dirt in front wheel bearings
Dirt in wheel bearings is non-metallic road grit or brake dust that has entered the bearing because of a worn seal, or it could be metallic particles that were left in the bearing housing the last time you had the rotors turned.
My recommendation for wheel bearing maintenance is to clean and inspect the bearings each time you replace brake shoes or pads. You should have the rotors turned at this time also. If the bearing shows signs of wear, replace it with a new inner and outer race. Pack each bearing with a good quality high pressure grease and install new seals.
Warning: I have noticed that some after-market rotors with an integral bearing housing are probably being sourced from China and have very poorly machined bearing seats for outer bearing races. These bearing seats can be rough, tapered, out of round and can lack concentricity between the inner and outer seats. These rotors must be replaced with good quality rotors to prevent premature bearing failure and wheel wobble.
I have also noticed the seal surface of some after-market wheel spindles aren't smooth enough, and the inboard seals are being chewed up in as little as 1,000 miles! If you find this to be the case then polish the seal surface on the spindle with fine emery paper until it has a bright appearance (the smoother the better). Replace the seal, and be sure to lubricate the rubbing surface of the seal with bearing grease at assembly.
Dirt in automatic transmissions
Dirt in automatic transmissions is non-metallic dirt from clutch disks and metallic (steel/cast iron and aluminum) dirt from normal metal parts wear.
My recommendation for metallic dirt is once again to use the old racer's trick of placing four or five permanent magnets from Radio Shack in the oil pan of the transmission. Again, be careful NOT to locate the magnets directly under the oil pump pick-up screen. The non-metallic friction material and aluminum is best addressed by changing the oil and filter in the transmission every 50,000 miles. Change more often if the transmission sees severe duty. When changing oil, I suggest the "converter and cooler flushing method" described on pages 14 and 15 in Ron Sessions Turbo Hydra-Matic 350 Handbook.
Dirt in manual transmissions and differentials
With the exception of broken gear teeth, you should never have any problems with a manual transmission or differential. They are basically sealed units and the systems themselves create very little metallic dirt. Just make sure you thoroughly clean any blasting grit from inside the housing, which may be left from cleaning the outside of the housing prior to painting or powder-coating. Believe me, this is not an easy job! There are still lots of places for grit to hide.
**** Z
http://www.streetrodstuff.com
**** Z - CEO
Streetrod Stuff, Inc.
