2011/11/14 Caterpillar

Pumper:

SPF343C (S/N: RTX1-UP)

Petroleum Transmission:

TH48-E80 (S/N: FRT1-UP)

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.

1. 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.

2. 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 .

3. In order to modify the clutch stations of the 261-3378 Pressure Control Valve Gp do the following.

   1. 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.

   2. In station C (clutch 1), remove the 9P-0687 Piston and replace with a 6T-2293 Piston

   3. In station E (clutch 5), remove the 7T-0569 Spring and replace part with a 7T-0571 Spring .

   4. In station G (clutch 6), remove the 7T-0569 Spring and replace part with a 7G-5453 Spring

   5. In station H (clutch 3), remove the 3T-1437 Piston and replace part with a 6T-2293 Piston .

4. 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 .

5. Perform Testing and Adjusting, RENR9663, "Pressure for Gear Pump (Transmission Charge)-Test and Adjust" by also using the modifications listed.

   1. Main Pressure must be a minimum of 2758 kPa (400 psi) at 800 rpm.

   2. Main Pressure must be 3254 kPa (472 psi) ± 207 kPa (30 psi) at 1300 rpm.

   3. Main Pressure must be 3400 kPa (493 psi) ± 207 kPa (30 psi) at 1900 rpm.

6. Perform Testing and Adjusting, RENR9663, "Pilot Pressure for Transmission Hydraulic Control Valve-Test and Adjust" by also using the modifications listed.

   1. The pressure on the gauge must be 2378 kPa (345 psi) ± 35 kPa (5 psi.)

   2. The priority pressure should be 2310 kPa (335 psi) ± 138 kPa (20 psi) in all gear ranges.

7. See Table 2 for the shim thickness pilot priority pressure spool valve with nested spring +8M-6402 Spring and 8M-6403 Spring
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   Table 2

   Shims for the Pilot (Priority) Pressure Spool Valve
   Part	Shim Thickness	Pressure Change
   5M-3492	0.25 mm (0.001 inch)	24 kPa (3.5 psi)
   7M-1397	0.9 mm (0.04 inch)	87 kPa (12.6 psi)

8. Perform Testing and Adjusting, RENR9663, "Primary Clutch Pressure for Transmission Hydraulic Control Valve-Test and Adjust" with the modifications listed below.

   1. Replace Primary Pressure values in Table 2 (Primary Clutch Pressure) in Testing and Adjusting, RENR9663, "Primary Clutch Pressure for Transmission Hydraulic Control Valve-Test and Adjust" with 420 kPa (61 psi) ± 35 kPa (5 psi) for station G and 860 kPa (125 psi) ± 35 kPa (5 psi) for all other stations.

9. Refer to Table 3 and Table 4 for test values.
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   Table 3

   Specification and Identification of the Components of the Pressure Control Valve
   Location of the Load Piston Body	A	B	C	E	G	H
   Thickness of the Load Piston Orifice	2.54 mm (0.100 inch)	2.54 mm (0.100 inch)	2.54 mm (0.100 inch)	2.54 mm (0.100 inch)	2.54 mm (0.100 inch)	6.60 mm (0.260 inch)
   Color of the Outer Spring of the Load Piston	Light Green	Light Green	Light Green	Light Green	Light Green	Light Green
   Color of the Inner Spring of the Load Piston	Light Blue	Light Blue	Light Blue	Dark Green	Yellow	Light Blue
   Size of the Decay Orifice	1.57 mm (0.062 inch)	1.57 mm (0.062 inch)	1.57 mm (0.062 inch)	1.98 mm (0.078 inch)	1.57 mm (0.062 inch)	1.57 mm (0.062 inch)
   Color of the Decay Orifice	Green	Green	Green	Red	Green	Green
   Overall Length of the Load Piston	58.5 mm (2.30 inch)	51.5 mm (2.03 inch)	58.5 mm (2.30 inch)	51.5 mm (2.03 inch)	51.5 mm (2.03 inch)	58.5 mm (2.30 inch)

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   Table 4

   Shims for the Pressure Control Valve (7)
   Valve Location	A	B	C	E	G	H
   Clutch that is engaged	4	2	1	5	6	3
   Thickness of the shim	Primary Pressure Change	Primary Pressure Change	Primary Pressure Change	Primary Pressure Change	Primary Pressure Change	Primary Pressure Change
   5J-2721 Shim
   0.13 mm (0.005 inch)	21 kPa (3.1 psi)	21 kPa (3.1 psi)	21 kPa (3.1 psi)	19.9 kPa (2.9 psi)	19.9 kPa (2.9 psi)	21 kPa (3.1 psi)
   6J-3993 Shim.
   0.025 mm (0.0010 inch)	41 kPa (5.9 psi)	41 kPa (5.9 psi)	41 kPa (5.9 psi)	38.3 kPa (5.6 psi)	36.5 kPa (5.3 psi)	41 kPa (5.9 psi)
   4M-1751 Spacer
   0.40 mm (0.016 inch)	65 kPa (9.4 psi)	65 kPa (9.4 psi)	65 kPa (9.4 psi)	61.2 kPa (8.9 psi)	58.4 kPa (8.5 psi)	65 kPa (9.4 psi)
   5J-1036 Shim
   0.80 mm (0.031 inch)	130 kPa (18.8 psi)	130 kPa (18.8 psi)	130 kPa (18.8 psi)	122.5 kPa (17.8 psi)	116.9 kPa (16.9 psi)	130 kPa (18.8 psi)

10. Perform Testing and Adjusting, RENR9663, "Clutch Pressure for Transmission Hydraulic Control Valve-Test and Adjust" with the modifications listed below. Refer to Table 5.
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    Table 5

    Clutch Pressure
    Valve Location			A	B	C	E	G	H
    Clutch that is engaged			4	2	1	5	6	3
    Transmission Gear Range	Engaged Clutches	Engine Speed	Pressure	Pressure	Pressure	Pressure	Pressure	Pressure
    NEUTRAL	1	Low Idle	0	0	2366 kPa (343 psi ) (1)	0	0	0
    		High Idle	0	0	2366 kPa (343 psi) (1)	0	0	0
    PARK	4 and 6	Low Idle	2331 kPa (338psi) (1)	0	0	0	2800 kPa (406 psi) (2)	0
    STALL	1,4, and 6	Low Idle	2331 kPa (338psi) (1)	0	2366 kPa (343 psi) (1)	0	2800 kPa (406 psi) (2)	0
    FIRST	2 and 6	Low Idle	0	(3)	0	0	2800 kPa (406 psi) (2)	0
    		High Idle	0	3490 kPa (506 psi) (2)	0	0	2800 kPa (406 psi) (2)	0
    SECOND	1 and 6	Low Idle	0	0	2366 kPa (343 psi) (1)	0	2800 kPa (406 psi) (2)	0
    		High Idle	0	0	2366 kPa (343 psi) (1)	0	2800 kPa (406 psi) (2)	0
    THIRD	2 and 5	Low Idle	0		0		0	0
    		High Idle	0		0		0	0
    FOURTH	3 and 6	Low Idle	0	0	0	0	2800 kPa (406 psi) (2)	2331 kPa (338psi) (1)
    		High Idle	0	0	0	0	2800 kPa (406 psi) (2)	2331 kPa (338psi) (1)
    FIFTH	1 and 5	Low Idle	0	0	2366 kPa (343 psi) (1)	(3)	0	0
    		High Idle	0	0	2366 kPa (343 psi) (1)	3355 kPa (487 psi) (2)	0	0
    SIXTH	2 and 4	Low Idle	2331 kPa (338psi) (1)	(3)	0	0	0	0
    		High Idle	2331 kPa (338psi) (1)	3490 kPa (506 psi) (2)	0	0	0	0
    SEVENTH	3 and 5	Low Idle	0	0	0	(3)	0	2331 kPa (338psi) (1)
    		High Idle	0	0	0	3355 kPa (487 psi) (2)	0	2331 kPa (338psi) (1)
    EIGTH	1 and 4	Low Idle	2331 kPa (338psi) (1)	0	2366 kPa (343 psi) (1)	0	0	0
    		High Idle	2331 kPa (338psi) (1)	0	2366 kPa (343 psi) (1)	0	0	0

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    ( 1 )	Tolerance is +/- 172 kPa (25 psi)
    ( 2 )	Tolerance is +/- 207 kPa (30 psi)
    ( 3 )	Clutch pressure is limited by available pump pressure at low speeds and should be checked at 1900 rpm.

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    Table 6

    Model	Effective With	Adaptable To
    SPF343C	S/N:RTX628-UP	S/N:RTX1-627
    TH48	S/N:FRT846	S/N:FRT1-845