0352947 EVINRUDE SCREW, Exhaust housing to cyl block

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PSP TO CORRECT GOVERNOR SURGING ON 3406B TRUCK ENGINES PS0234 - US, CANADA, COFA, TRUCK TEPS - SEE SUPPLEMENT 85-03-29
  The information supplied in this service letter may not be valid after the termination date of this program.   Do not perform the work outlined in this Service Letter after the termination date without first contacting your Caterpillar product analyst.
PRODUCT SUPPORT PROGRAM TO CORRECT GOVERNOR SURGING ON 3406B TRUCK ENGINES (Parts Stock Action Needed), 1264, 1287, PS0234 U-14 AU-12 C-12 TT-3 See March 29, 1985 Problem Some drivers of trucks powered by the 3406B Engine may complain of "vibration", "bounce", or "rough ride". In some cases these complaints can result from engine governor surging under part load, part "throttle" conditions. A new governor housing and a new guide provide more oil flow to the dash pot, and a stiffer dash pot spring is used. See Illustration. These parts reduce the surging by giving improved dampening of the governor. They will not correct such complaints caused by the truck itself. See topic "Action Requested". Affected Engines And Parts Needed The ending engine serial number is not available. Engines that are eligible under this Program have serial numbers 7FB1-Up, and certain fuel injection pump group serial numbers. This number is stamped on the top surface of the injection pump housing near the fuel lines. Perform the "Action Requested" before any parts are ordered. The following Table (A) lists only the new, improved parts needed. All the remaining parts in Table (B) should be installed. All injection pump groups with serial numbers below 32814 need all the parts listed in Table (B). (SEE ILLUSTRATION) Affected Parts - TABLE (B) 1 - 7W4247 Housing Assembly * 1 - 5F9144 Seal 1 - 7W4882 Spring (Dashpot) * 1 - 6H9691 Seal 1 - 7W4182 Body * 2 - 2W5447 Gasket 1 - 8N9384 Gasket 1 - 3L6768 Seal 2 - 7N8821 Ring 1 - 5P6620 Seal 1 - 6V5029 Seal 1 - 335879 Seal 1 - 8N3763 Gasket 1 - 5P5601 Seal 2 - 1J9671 Seal 1 - 8N6680 Screen Assembly 1 - 8N3765 Gasket 1 - 2D6392 Seal 1 - 8N3761 Gasket 1 - 8N9382 Gasket * New parts - the housing assembly includes improved guide. Action Requested (Parts Stock Action Needed) Effective analysis of this problem is difficult because many things in a truck can cause complaints of "vibration", "bounce", or "rough ride". Governor surge occurs only when the governor is at low load, part throttle, usually at 10 psi (70 kPa) boost or lower. It cannot occur when the rack is solid against the rack stop. Therefore, if governor surge is the cause of or is contributing to the problem, the problem should cease or almost cease when the foot "throttle" is moved to the maximum rack position. Two primary causes of governor surge are cab/throttle movement or cyclic changes in drive train loads, such as when hitting bumps on the road. If pulling out the dash mounted hand "throttle" (usually connected to a cable) reduces or corrects the condition, then cab motion is the cause and the new parts will only improve the condition to the same extent that the hand throttle did. Next, put the transmission in neutral or disengage the clutch. If the problem still occurs, it is not caused by governor surge and installation of the new parts will not correct the problem. The complaint may result from an engine-truck combination problem. Installation of the new parts will correct the engine portion, but of course will not correct the truck portion, so the user will not be completely satisfied. If you believe the new parts are needed after your investigation, install the new parts as follows: 1. Measure high idle. 2. Replace the dashpot spring with the new spring. Illustration. You may need to bend the spring slightly to get a good alignment of the piston on the shaft. (SEE ILLUSTRATION) 3. Replace the rear governor housing with the new housing. a. Remove the internal linkages from old housing and install in the new housing, including the reservoir cover. See Illustration. b. Reuse external parts, such as idle adjustment screws and rack contact. c. Install new 6V5029 Seal for the manual shutoff shaft. : Be sure the toes of the flyweights are behind the riser bearing or else the flyweights and the rear housing will be broken when the engine is started. Also, if the engine S/N is less than 7FB6811, remove the flyweight shield if not already done. Refer January 6, 1984 Safety Service Letter PI1019 (revised March, 1984). Additionally, if new piston cooling jets are needed, do this work too. See January 30, 1985 Service Letter, PI3096. 4. Set low idle at 700 rpm and set high idle to that measured before disassembly. It is not necessary to reset full load rack, full torque rack (full load setting plus torque rise), the AFRC (air fuel ratio control), the shutoff solenoid, or the manual shutoff. 5. Install the new oil supply body in the new housing. Illustration. 6. Reuse the same needle valve in the new body. Install the valve 2 1/2 turns loose. Also, remove the following parts from your parts stocks. 8N9679 Governor Housing 8N2499 Guide 4N5485 Body 7W4067 Spring Warranty Allowances Caterpillar