MKuhns - 3208 Question

Sorry to keep beating this dead horse, but my service manual for the 3208 showed up yesterday. It is manual SEBR0507-01 for 3208 Industrial & Marine Engines, for SN 75V1-UP and 90N1-UP, which matches the SN's for the 3208s in our tractors. The section for Injection Pump timing gives the same instructions for timing the pump that I used last week to time the pump on my 2-180, but that never worked until we 1st pinned the pump, and then turned the crank backwards (CCW as you look at the front of the engine) until the engine timing pin slipped in (similar to the instructions you gave here).

Sorry for asking what is probably a simple question multiple times, but since its not addressed in the service manual, I'm trying to figure out if your instructions to turn the crank backwards a 1/4 turn then snug the injection pump gear is something that you've learned with experience, or if this is symptomatic of my engine gear train being worn, or something else? Any feedback would be appreciated. Thanks.

Mitch the 3208 service is too new for me but I was always taught when you time the (any) pump and you have the drive gear bolted down back it up about a quarter turn and then come back to make sure all the backlash is out of the gear train.

I simply turn the engine counter clockwise 1/4 turn and then clockwise to pin the engine to get the backlash out. I do it this way to eliminate having to turn the engine over 2 times to remove the backlash and getting it to pin again. You would snug the gear prior to turning the engine over the 2 times. (They tell you to do it like this for a 3406 to time the pump) According to the Cat, they pin the pump first. Then they pull the gear loose. Next they tell you to turn the engine over until the pin falls into the cam. Then they tell you to install the new pump and torgue the gear. This procedure take out most of the backlash, except for the pump drive gear, which would be loose until tightened onto the pump. In any event the timing would be off, unless the pump gear is rotated in normal rotation (CW from front of engine)with friction against the gear. I guess backing up the engine 1/4 CCW and then going clockwise to pin the engine is normal practice to eliminate backlash as J Schweibert said also. That engine also has a 3-5 degree centrigual advance the the injection pump gear runs off of. By turning the engine CCW you could be forcing it to advance also, affecting timing. Another issue I heard of quite often is so Reman injection pumps didn't have the timing slot in the pump located at the correct spot, makin it impossible to correctly time and engine using two pins.