- Wheel Loaders:
- 936 (PIN: 4SB1-UP; 33Z1-UP; 45Z1-UP)
- Integrated Toolcarriers:
- IT62G (PIN: 6PS1-UP; AKP1-UP)
- Load Haul Dumps:
- R1300 (PIN: 6QW1-UP)
- 936E (PIN: 4SB1-UP; 33Z1-UP; 45Z1-UP)
- 936F (PIN: 8AJ1-UP; 4TK1-UP; 9MK1-UP)
- G936 (PIN: 3HD1-UP; 4ND1-UP; 8ED1-UP)
- 950B (PIN: 31R1-UP; 63R1-UP; 65R1-UP; 22Z1-UP)
- 950E (PIN: 63R1-UP; 65R1-UP; 22Z1-UP)
- 950F (PIN: 7ZF1-UP; 6YG1-UP; 4DJ1-UP; 2LM1-UP)
- 950F Series II (PIN: 4DJ1-UP; 5SK1-UP; 8TK1-UP)
- 950G (PIN: 2JS1-UP; 4BS1-UP; 6NS1-UP; 3JW1-UP; 5FW1-UP; 5MW1-UP; 8JW1-UP)
- 960F (PIN: 9ZJ1-UP; 4CL1-UP; 6XL1-UP; 1YM1-UP)
- 962G (PIN: 3BS1-UP; 5AS1-UP; 5RS1-UP; 9BS1-UP; 4PW1-UP; 6EW1-UP; 6HW1-UP; 7BW1-UP)
- 966C (PIN: 18B1-UP; 9KC1-UP)
- 966R (PIN: 58Z1-UP)
Reference: Service Magazine, SEBD1678, September 1986, "Pressurized Lubrication for First Speed Planet Gear Bearings".
Description of Change: A new slotted clutch piston is available. The new clutch piston is manufactured with eight slots that increase oil flow behind the piston seals. The increased oil flow improves the seating of the oil seals. The improved seating of the oil seals eliminates possible shift hesitation and/or reduced clutch pressure. If the oil seals are not seated properly, shift hesitation may occur when the transmission is shifting into second speed. Properly seated clutch piston seals do not allow oil to flow past the clutch piston seals. If oil flows past the clutch piston seals, the oil can generate a thrust load on the bearing that supports the rotating clutch housing. A thrust load on the bearing may result in reduced bearing life.
Adaptable To: The new 176-9273 Piston replaces the former 9G-5818 Clutch Piston (cancelled). The only difference between the 176-9273 Piston and the 9G-5818 Clutch Piston are the eight slots that have been added to the clutch piston. The 176-9273 Piston is effective with the following machines:
| 176-9273 Piston Machine Effectivity | |
| Machine Sales Model | Machine Serial Number |
| 950G Wheel Loaders | (PIN: 2JS852, 856, 871-878 and 880-UP) |
| (PIN: 4BS536-UP) | |
| (PIN: 6NS251-UP) | |
| (PIN: 3JW1147, 1151-1161, 1163-1184 and 1186-UP) | |
| (PIN: 5FW1192, 1193, 1204, 1207-1213, 1215-1217 and 1219-UP) | |
| (PIN: 5MW494-UP) | |
| (PIN: 8JW288-UP) | |
| 962G Wheel Loaders | (PIN: 3BS550-556, 561-563, 565-569, 571-574 and 576-UP) |
| (PIN: 5AS302-UP) | |
| (PIN: 5RS220-UP) | |
| (PIN: 4PW326-UP) | |
| (PIN: 6EW260-UP) | |
| (PIN: 6HW303-UP) | |
| (PIN: 7BW514-UP) | |
| IT62G Integrated Toolcarriers | (PIN: AKP337-339 and 341-UP) |
| R1300 Load Haul Dumps | (PIN: 6QW894-UP) |
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| Illustration 1 | g00711432 |
Transmission Planetary Group (Typical Example) (1) Seal ring. (2) First speed clutch planetary carrier. (3) Clutch piston. | |
Note: Service Engineering recommends updating any transmission that is removed and disassembled. Make sure that the transmission is equipped with seal ring (1) before updating the transmission. Some 950B, 950E, 966C and 966R Wheel Loader transmissions are not equipped with seal ring (1). If the transmission is not equipped with seal ring (1), the update provides no benefit.Modification Procedure
Transmissions may be updated with either of two methods. The existing 9G-5818 Clutch Piston (3) can be replaced or modified. Replace the 9G-5818 Clutch Piston (3) with a new 176-9273 Piston. Modify the 9G-5818 Clutch Piston (3) by using the procedure that follows.
Note: Some of the 936, 936E, 936F, G936, 950B, 950E, 950F, 966C and 966R Wheel Loaders transmissions are built with less than five friction discs in the number five clutch. These transmissions are not equipped with the 9G-5818 Clutch Piston. If the transmission was not originally equipped with the 9G-5818 Clutch Piston, the new 176-9273 Piston cannot be installed. The existing clutch piston may be machined in order to add the slots. The new slots will increase oil flow.
- Machine four slots (4) at 90 degree spacing on seal ring groove (5). Use a cutter with a 19 mm (.75 inch) diameter in order to machine the slots. Dimension (F) equals 5.7 mm (.23 inch). Dimension (G) equals 2 mm (.079 inch).
Note: Make sure that the opposite side of the seal ring groove (6) is not damaged when the slots are machined.
 | |
| Illustration 2 | g00711539 |
(4) Machined slots. | |
 | |
| Illustration 3 | g00713994 |
Section E-E (4) Machined slot. | |
 | |
| Illustration 4 | g00711822 |
Detail C (5) Slot in the seal ring groove. (6) Opposite side of the seal ring groove. | |
- Machine four slots (4) at 90 degree spacing on seal ring groove (7). Use a cutter with a 19 mm (.75 inch) diameter in order to machine the slots. Dimension (H) equals 2 mm (.079 inch).
Note: Make sure that the opposite side of the seal ring groove (8) is not damaged when the slots are machined.
 | |
| Illustration 5 | g00711823 |
Detail D (7) Slot in the seal ring groove. (8) Opposite side of the seal ring groove. | |
- Carefully deburr the slots, as needed.