FILTER- 3764808 - Caterpillar

minimum since there is a difference in readout between ASTM D6643 and ASTM D2896." In the place of this sentence, use the information which follows: "New oils generally measured for TBN by ASTM procedure D2896. If this method is also used for monitoring oil condition, we recommend the condemning limit be 50% of the new oil TBN value. There is a difference in condemning limits because ASTM procedure D2896 readouts do not coincide with ASTM procedure D664 readouts".
--------------- END SUPPLEMENT ---------------In the past 30 years, fuel sulfur wear in engines has been minimized through the use of correct lubricants, adherence to the correct oil change intervals, and the efforts of the fuel refiners. Recently, we have been receiving reports that fuel sulfur wear is increasing. Many of today's servicemen and machine operators are not familiar with this type of wear. This article answers some of the questions most frequently asked by engine owners, operators and service personnel.
1. What causes fuel sulfur wear?
Fuel sulfur wear is caused by the corrosive effect of sulfuric acid formed from combustion gases. An explanation of this corrosive wear appears in the February 5, 1979 Service Magazine. (March 7, 1979 Engine News.)
2. How do you recognize fuel sulfur wear?
It causes severe ring and liner wear, plus wear in the exhaust valve guides. Unlike abrasive wear, there will be little or no crankshaft wear. Bearing damage can result from foreign material bypassing the soot-filled oil filters. In very bad cases the bearing surface could show pits.
3. How can fuel sulfur wear be eliminated?
It probably never will be. As long as crude oils contain sulfur, this type of wear can be a problem. But, if you must use high sulfur fuel (and, there will be times and areas where its use cannot be avoided) engine damage can be minimized:
First, through the use of the correct lubricant to protect and clean engine parts. Caterpillar recommends the use of CD quality oil.
Second, by more frequent oil changes. For 30 years Caterpillar has recommended that the oil be changed at ONE-HALF NORMAL OIL CHANGE INTERVALS whenever the sulfur content in the fuel is between .4% and 1%.
4. How can we know we have a CD oil?
Oil quality and type have to be assured by the oil supplier. You can obtain the suppliers' brand names for CD oil by using Caterpillar Form GEG05044-02, which lists the various oil brands and their quality.
5. Why is there more wear due to sulfur in the past 2 years?
There are several causes:A. Diesel fuel standards in most countries have always permitted 1% fuel sulfur. However, in the past, fuel suppliers have provided a product under this limit. Now, it is doubtful whether refiners can continue to supply lower sulfur fuel while sulfur increases in the crude supply. Many are now supplying fuel containing almost 1% sulfur.B. Many users have neglected to change oil according to our recommendations. They had little trouble as long as fuel sulfur was near .6%. Now, with fuel sulfur between