Tuesday, July 21, 2009

Why Tech manuals are important!

I had a call earlier from a customer looking for an injection pump for a JD tractor. He said his tractor would crank and run but it smoked real bad and did not have any power. I asked questions about what had been done and why did he think he had an injection pump problem. He then said he rebuilt the engine and did not put new rod bolts in it and the rod bolt broke and wedged in the cam gear and sheared the cam gear and nose of the cam off. I asked him how he timed the injection pump and the cam. He said he lined up the mark on the gear with the center of the crankshaft. Which is basically what you do to time the engine. I asked him did he have the #1 piston at top dead center on the compression stroke and I lost him here. He had just timed the cam and pump to the center of the crankshaft. He did not set the crankshaft in the proper position before timing the cam and pump. I figure it is a couple of teeth out of time, close enough so it will crank but not on the money so it will have power. The front of the motor has to come back off to retime the engine.
There are 2 things here to know and remember.
A: Never rebuild a John Deere engine using the old rod bolts! Always put in new ones!!!!!
B: Always follow proper procedures to time your engine when you have replaced timing
components !!!!

Eric Benton, Southeast Tractor Parts, Understand what makes your tractor run, Buy a Tech Manual!!

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