What would cause the woodruf key on the injector pump gear to be nearly sheared flat? The truck was running rich and smoking excessively. The timing was way off and could not be adjusted by rotating the injection pump. On disassembly the woodruff key in the gear on the backside of the injection pump was nearly beaten flat. There are no apparent dings or marks on any of the timing gear teeth. The killer dowel pin is still in place and will be fixed with the appropriate washer while this is apart. How can this gear beat up a woodruff key like that?

Rocky
'93 Dodge TCD

 

Have you had the truck a while or is it new to you?

 

The truck is fairly new to me. I bought it from an older man 4 months ago. He used it to tow a trailer but it only has 140,000 miles on it. It started smoking within weeks of purchasing and I have been chasing it down ever since. My mechanic said someone previously left the timing pin engaged after they timed the truck and started it up. It sheared that pin off but he felt that since the pin is plastic and probably didn't do any damage. There does appear to be a timing issue as the exhaust smelled like fuel and the truck lacked power. It acted like the timing was too far retarded but when you rotated the pump to advance it, it would not run at all. We decided to remove the front timing gear cover to check the gears to see if they had spun on the injector pump shaft when the pin sheared and found the woodruf key almost gone. Apparently the gear had jumped a bit and the timing was all screwed up. There is no apparent damage to any of the crank or timing gears, just the flattened Woodruf key. Could that plastic pin have created that much force to destroy the woodruff key?

Rocky
'93 Dodge 3/4 ton CTD

 

Any nasty oil leaks on the front of the engine? If the KDP came loose, it could cause anything in that area some grief, just before punching a hole in the timing case.

 

No leaks at all. I checked the KDP and it is still in it's hole. It will be secured before reassembly.

Rocky

 

Beats me. I've heard of guys putting the gear on out of line and mashing the key but yours sounds like it sheared in action. Was the nut loose at all?

I'd put in a new key and run it.