[curtis c.]

I started tearing apart my 4bt & got stuck on the crank pulley. It's so tight I'm afraid the bolts will break off & got to wondering if they may be left hand thread. Are they left hand? Anybody have any other disassembly tips? Are the lifters like a flat tappet gas engine & have to stay with the same cam lobe?Any timing marks to pay attention to? Any hidden head bolts? This is my 1st diesel & don't want to over look anything that will make this project cost more money.Thanks for any help. Curtis

 

[scout4bta]

Curtis,
First thing you gotta do is get a Cummins manual for the engine. Write down you engine serial number, go to Cummins and they will get you the one for your engine. Yes these engines are simple, but not that simple that you can tackle a rebuild with out a manual. That's all I'm going to say.

 

[BobS]

Those four retaining bolts were torqued to around 92 ft/lb when they were installed. The threads have a tendency to pick up moisture and rust if the engine was used in an industrial application. Soak them with PB Blaster or Kroil overnight, then use a half inch drive impact wrench with a six point metric impact socket. Do not use any other type of socket because a twelve point will usually round off the head and a non impact socket can break. The threads are metric RH so they loosen by turning them counter clockwise.

 

[Machman]

Another trick:

If they don't loosen up in the first few moments with the impact going CCW, try going CW for a second or two, re-oiling, then hit it CCW again.