Usage:
PIPELAYERS
D6H (3ZF, 6CF, 4YF, 3YG, 5HF, 4GG, 1FJ, 2DK, 9KJ, 9LK, 8SK, 6CK, 1YL, 2TL, 4RC, 3ED, 7PC, 4LG, 2KD, 6FC, 8YC, 2TG, 6JJ, 1KD, 8FC, 8KB, 8ZJ, 8KK, 9RK, 5KK, 2BL, 7ZK),D6R (2YN, 8LN, 6JN, 4MN, 3ZN, 9PN, 7KN, 5LN, 2HM, 4HN, 8XN, 4JR, 4FM, 8TM, 9MN, 9BM, 6FR, 7AR, 6HR, 4WR, 5PR, 4TR, 7DR, 5RR, 7CR, 9ZS, 6GR, 6MR, 1RW, 7GR),
D7H (77Z, 79Z, 4AB, 80Z, 82Z, 5WB, 5BF, 2RG, 2SB, 4FG, 3XG),
D7R ( 2HR, 9HM, 2EN, 3DN, 3ZR, 4SR, 5MR, 6ER),
D8N ( 1XJ, 5TJ, 7TK, 9TC),
D8R (7XM, 9EM) TRACK-TYPE TRACTORS;
572R (AAC, 2HZ),
578 (8HB),
583R (2XS) PIPELAYERS
Problem:
Some reports of turbine-stator and impeller-stator rubbing have been received on current production D6R, D7R, and D8R machines as well as previous models D6H, D7H, and D8N Track-Type Tractors. The wear generates debris that can plug filters and damage other components in the power train oil system. The clearances between the torque converter wheels are being increased for the second time.
Information on the first increase in 1995 was never published, which has added an element of confusion to the situation.
Solution:
The clearances have been increased twice since first production of the D6H, D7H, and D8N Track-Type Tractors. The first change (Table 1: Change I) was effective in October 1994 on the D8N machine and in June 1995 on the D6H and D7H machines. The nominal clearance (diameter difference) between the stator and turbine was changed from 0.381 to 0.934mm (0.015 to 0.037inch). This change was implemented by reducing the outer diameter of the stator (Table 3). The stator part numbers were changed to the interim stator part numbers. The dimensions of the impeller and turbine have not been altered.
The second increase in clearance (Table 2: Change II) has just been released and will be effective in production shortly. However, parts with the new increased clearances are already available through the parts system. The nominal clearance between the stator and turbine is being increased from 0.934 to 1.854mm (0.037 to 0.073 inch). Additionally, the clearance between the stator and impeller is being increased from 0.305 to 1.243mm (0.012 to 0.049 inch). This change was implemented by changing both the inner and outer diameters of the stator (Table 3). The stator part numbers are being changed to the new stator part numbers. The dimensions on the impeller and turbine are not being altered. All of the included tractor models should be using these new stators and larger clearances for field service.
With the increased nominal clearances, the 100% worn clearances have changed as well. All three of the included models have identical clearances for new and 100% worn (Table 4).
NOTE: This is the measured difference between the component diameters.
COPYRIGHT 1999 CATERPILLAR ALL RIGHTS RESERVED