BLEED NIPPLE 4U7851 - Caterpillar

TECHNICAL INFORMATION BULLETIN JULY 09, 2003
TRACK-TYPE TRACTORS
TRACK TYPE LOADERS
TRACK TYPE SKIDDERS
EXCAVATORS D5B (8MB 5LD 8HD 22X 23X 24X 25X 26X 43X 44X 45X 46X 21Y);
D5H (8RC 7NC 1DD 9HC 8RJ);
D6D (19B 5YB 36C 37C 38C 6HC 7YK 9FK 74W 75W 3X 4X 5X 6X 19X 20X 01Y 7XF);
D6E (2MJ 8FJ);
D6G (3SR);
D6H (4RC 4LJ 7PC 3ZF 6CF 1FJ 8ZJ 8KK 9KJ 9LK 5KK 2BL 6CK 1YL 6FC 2TG 8YC 3YG 5HF);
D6N (ALH AKS ALR ALY);
D6M (3WN 9ZM 4JN 2RN);
D6R (2YN 2HM 9ZS 3ZN 4FM 1RW 4MN 4JR 6MR 5LN 9BM 7GR DMP 6JN 8XN 7KN 9MN 8LN 4HN 9PN 8TM AFM AEM BPM BRJ BLT BLE AXX AGM BMY BMJ AEP DAE ADE ACJ BNC);
953 (76Y 77Y 05Z 20Z 5MK 2ZN BBX);
963 (06Z 11Z 18Z 21Z 9BL 2DS BBD);
955 (48H 61H 64J 85J 72A 60A 13X 8Y);
517 (5WW 6PW);
527 (4NS);
215B (4FC 4JC);
225 (51U 76U 2ZD);
Component Code(s) 4175SUBJECT: POSSIBLE CRACKING OF SALT (Sealed And Lubricated Track) LINK ASSEMBLY TRACK PINS
PROBLEM: A limited range of heavy duty and regular SALT track pins were improperly heat treated, creating potential for cracking. Two forms of pin cracking can occur. Both forms are primarily cosmetic and will not generally result in pin failures or oil leaks. The first form of cracking can occur on the pin end, in a concentric partial or complete circle around the oil hole. This is illustrated in the picture below:
This crack is relatively shallow and sometimes forms only partially around the end of the pin. A small ring of this material on the pin end may separate off the pin end. This would most likely occur at the track bushing turn time, during disassembly.
The second form of cracking can occur around the track pin oil cross-hole on the outside diameter pin surface. A "football" shaped piece of the O. D. surface (approximately 1/8" or 3mm thick) can break loose. This is referred to as pin surface spalling. An example of this is shown below:
This failure would most likely be found upon track link disassembly at the bushing turn. This spalled piece may or may not be attached to the pin.
SOLUTION: Track pins are made several places around the world, depending on the machine model and pin size. The track pins in question were made in Grenoble, and assembled in track at Grenoble and East Peoria. Most machine and parts replacement link assemblies, as well as loose pins have been sorted and inspected for cracks. However, a small number of link assemblies or loose pins may have missed inspection or later may develop cracks once on the machine. Affected track pin part numbers and machine models are as follows:
Pin Part No. Machine Model Description
179-0126 D5H, D6M, D6N Tractors Heavy Duty SALT
517 Skidders
160-7820 D6H, D6R Tractors Heavy Duty SALT
527 Skidders
160-7818 D5H, D5B Tractors Regular SALT
953, 955 Loaders
215,