Greetings from the 73-79 forum! I'd like to jump in here because a buddy of mine has the same problem. We changed the terminals (they were f'd) to the batt, got a new starter, tested it before it went on, charged the batt, and it has the same problem. The started engages and it kicks the motor but the motor won't turn. Pulled the inspection plate, marked the flywheel, turned the engine with a breaker bar (with the belts connected) multiple revolutions. Couldn't see any irregularities in the ringear, and there didn't appear to be much run out. Interestingly the 1st starter that I put on the truck ( a new, not rebuilt replacement from advance) ended up breaking at the snout. The 2nd relacement (rebuilt, which is much better, there is more material around the shaft unlike the new remy) hasn't broken but the problem remains. Any ideas? I'm assuming since I can turn it by hand that it isn't hydrolocked. Am I correct? This is baffling. Thanks guys.


Josh

 

If the starter snout snapped off it was either defective or not mounted correctly. If the starter attempts to crank the engine the LOAD and CONTROL circuits are both working properly so you're bad to engine mechanical problems. How hard is it to turn the crank manually? Did you turn the crank through two complete revolutions to complete the 4 stroke cycle? Do you detect any point where the effort required to turn the crank increases? You starter should have an overrun clutch which should protect it from breaking in the case of a mechanical bind.

 

The starter was definitely defective. I agree that the starting circuit is working properly. I also agree that there is something mechanical. However me and another friend of mine marked the ring gear and turned the engine through several complete revolutions to check for any abnormalities (or to see if something would fall out). we could find nothing. We did not put a dial gauge on the ring gear though because we did not have one to use. The funny thing is that my buddy who has the truck drove it the night before with no problems. Then the next morning it wouldn't start. He was almost 3 qts low on oil but I'm pretty sure that isn't the problem. If it was seized we wouldn't be able to turn it by hand right? The only time the engine was harder to turn was on the compression stroke. So if there is mechanical bind then the overrun clutch will stop the movement, meaning that even if we can turn the motor by hand, the force needed might still be greater than the clutch will allow.

I appreciate your ideas,

Josh

 

Maybe you did get a defective starter out of the box. It happens. The snout is probably is cast aluminum. The casting could fail under load. The load is about 650 amps initial crank current and even more when the engine is cold and when the temp is low outside as it is right now. The current is going to go way up when cold.

 

I think it was defective. It was a new one and not a reman. The snout has a lot less material than the factory or reman starter. It broke off at the mounting base. We went back and swapped it out for a reman. Much better starter, but still no crank.

 

Does it attempt to crank? Does the crankshaft even show signs of trying to rotate? If it does the control circuit is good. The load circuit could be at fault or you have a mechanical bind. When you try to crank the engine do you hear the overrun clutch begin to slip? Do you have a fully charged BATT with clean tight terminals that have good mechanical and electrical bond?