- Engine:
- 3512C (S/N: TKP1-UP; T3P1-UP; T3R1-UP; T3S1-UP; T3W1-UP; T3Y1-UP)
- 3516C (S/N: TKR1-UP; TKS1-UP; TKT1-UP; TKX1-UP; TKY1-UP)
Description of Change: The new tube offers increased clearance to prevent wear on the face of the tube.
Adaptable To: The new 475-4256 Tube replaces the existing 8N-9706 Tube and is adaptable back to first production on the serial numbers listed above.
Note: A new flange will be required when using the new tube.The new 475-4255 Flange replaces the existing 8N-9609 Flange .
Refer to Table 1 for the new and former part numbers.
| New Part Number | Former Part Number |
| 475-4256 | 8N-9706 |
| 475-4255 | 8N-9609 |
 | |
| Illustration 1 | g03838065 |
(1) 475-4256 Tube (2) 475-4255 Flange | |
 | |
| Illustration 2 | g03838084 |
(3) Face of tube (4) Circumference if tube | |
If there is wear or corrosion, only on the circumference of the tube then replace the tube with the existing 8N-9706 Tube .
If there is wear on the face of the tube, then replace the existing tube with the new 475-4256 Tube .
Refer to Table 2 for a list of part numbers needed to install the new tube.
| New Part Number | Description | Quantity |
| 475-4256 | Tube | 2 |
| 475-4255 | Flange | 4 |
| 2N-0931 | Gasket | 4 |
| Effective Serial Numbers |
| S/N:T3P00287-UP |
| S/N:T3R00293-UP |
| S/N:T3S00218-UP |
| S/N:T3W00251-UP |
| S/N:T3Y00002-UP |
| S/N:TKP00232-UP |
| S/N:TKR00218-UP |
| S/N:TKS00234-UP |
| S/N:TKT00244-UP |
| S/N:TKX00206-UP |
| S/N:TKY00354-UP |