SCREEN-SUCTION 2075993 - Caterpillar

Pumper:
SPF343C (S/N: RTX1-UP)
Petroleum Transmission:
TH48-E80 (S/N: FRT1-UP)
Service Magazine SEPD1357, 14 November 2011, "Hydraulic Control Modifications for TH48-E80 Petroleum Transmission and SPF343C Pumper Transmission". Disregard this article. See the article that follows.Problem
Issues have been reported regarding the TH48-E80 Petroleum Transmission, extended clutch fill times cause output speed to drop during shifts.Solution
Modification of the transmission controls will increase some clutch top pressures and reduce clutch fill times. This modification will minimize the opportunity for output speed to drop during shifts.
Table 1
Required Parts    
Qty    Part No    Description    Former Part Number    
1    367-2179     Pressure Control Valve Gp    261-3378    
3     6T-2293     Piston     n/a    
1     7G-5453     Spring    
1     7T-0569     Spring    
1     7T-0571     Spring    
1     8M-6403     Spring    
1     8P-9737     Cascade Orifice    
1     9G-7132     Orifice Plug    
1     9W-7412     Spring    
Modify the 314-9930 Selector and Pressure Control Valve (with stall mode) or 261-3383 Selector and Pressure Control Valve (without stall mode) by adding one 8M-6403 Spring. Note: The 8M-6403 Spring. will be nested inside the existing 8M-6402 Spring.
Remove and discard the 1P-9620 Retaining Ring from the 6T-3696 Reducing Spool Assembly. This step is to avoid interference with the 8M-6403 Spring .
In order to modify the clutch stations of the 261-3378 Pressure Control Valve Gp do the following.
In station A (clutch 4), remove the 9P-0687 Piston, 7G-5453 Spring, 9W-7410 Spring, 273-3533 Orifice and 9G-7131 Orifice Plug. Replace these parts with the 6T-2293 Piston, 7T-0569 Spring, 9W-7412 Spring, 8P-9737 Cascade Orifice and 9G-7132 Orifice Plug.
In station C (clutch 1), remove the 9P-0687 Piston and replace with a 6T-2293 Piston
In station E (clutch 5), remove the 7T-0569 Spring and replace part with a 7T-0571 Spring .
In station G (clutch 6), remove the 7T-0569 Spring and replace part with a 7G-5453 Spring
In station H (clutch 3), remove the 3T-1437 Piston and replace part with a 6T-2293 Piston .
Shim as needed to achieve initial pressures. The following shims are used 4M-1751 Spacer, 5J-2721 Shim, 5J-1036 Shim and 6J-3993 Shim. Note: Suggested starting shim thickness is 5.5 mm (0.22 inch) for station G and 8.2 mm (0.32 inch) in all other stations.A new Pressure Control group is available through the parts system with this modification. The new 367-2179 Pressure Control Valve Gp replaces the 261-3378 Pressure Control Valve Gp .
Perform Testing and Adjusting, RENR9663, "Pressure for Gear Pump (Transmission Charge)-Test and Adjust" by also using the modifications listed.
Main Pressure must be a minimum of 2758 kPa (400 psi) at 800 rpm.
Main Pressure must be 3254 kPa (472 psi) 207 kPa (30 psi) at 1300 rpm.
Main Pressure must be 3400 kPa (493 psi) 207 kPa (30 psi) at 1900 rpm.
Perform Testing and Adjusting, RENR9663, "Pilot Pressure for Transmission Hydraulic Control Valve-Test and Adjust" by also using the modifications listed.
The pressure on the gauge must be