8N Destroyed camshaft timing gear, what did I do wrong?

[That_guy]

I have been putting the 1950 8N back together after doing some "refreshing" on it and went to start it. After about 2 attempts to crank I stopped as it was making a weird sound. Started investigating and noticed the timing cover housing that the governor attaches to was cracked. I removed the governor and found that the camshaft timing gear was destroyed and metal pieces all over the place. What could have caused this?

How hard is it to replace the camshaft timing gear and timing cover housing that the governor attaches to? From what I can tell it looks like the gear bolts on the camshaft with four bolts so theoretically I should be able to replace it by bolting on a new one?

 

[mhb@ufe]

View attachment 65905
I have been putting the 1950 8N back together after doing some "refreshing" on it and went to start it. After about 2 attempts to crank I stopped as it was making a weird sound. Started investigating and noticed the timing cover housing that the governor attaches to was cracked. I removed the governor and found that the camshaft timing gear was destroyed and metal pieces all over the place. What could have caused this?

How hard is it to replace the camshaft timing gear and timing cover housing that the governor attaches to? From what I can tell it looks like the gear bolts on the camshaft with four bolts so theoretically I should be able to replace it by bolting on a new one?

That was caused from installing too long of a bolt in the upper governor mounting hole. It should be a bolt on cam gear so won't be difficult to replace once you get everything apart to get to it.

 

[That_guy]

That was caused from installing too long of a bolt in the upper governor mounting hole. It should be a bolt on cam gear so won't be difficult to replace once you get everything apart to get to it.

Ok, thanks for the response. I think I read about not doing that on a post a while back and then somehow still did it, really hurts to be dumb and stupid.

 

[mhb@ufe]

Ok, thanks for the response. I think I read about not doing that on a post a while back and then somehow still did it, really hurts to be dumb and stupid.

Don't beat yourself up too much as you were not the first and probably won't be the last.

 

[Hobo,NC]

Ok, thanks for the response. I think I read about not doing that on a post a while back and then somehow still did it, really hurts to be dumb and stupid.

By the time you get the front apart you can have the engine on a engine stand and remove the oil pan and clean all that junk out of the pan. In other words do the job correctly. The repair will go so much better... : )

 

[KCTractors]

Ok, thanks for the response. I think I read about not doing that on a post a while back and then somehow still did it, really hurts to be dumb and stupid.

That is the only way you learn, been there, done that. If you never screwed up, you never did anything!!

 

[used red MN]

That is the only way you learn, been there, done that. If you never screwed up, you never did anything!!

Hello that guy, welcome to YT! I may have greeted you before but what the heck.

That is the only way you learn,

Not intending for additional beating, let’s take the opportunity to “learn” from it. Doing mechanical tasks takes a lot of attention to detail to make the end product a success. The disassembly of something has almost as much criticality as the assembly. Noting the length of the bolts that were removed would have saved you a lot of grief here. During assembly pre-fitting the bolts in the holes prior to assembly glancing quickly at their thread penetration would likely have given you a clue to an impending problem. As a final measure, most likely driving the long bolt into the gear teeth your bolt was meeting some resistance. Your mind told you “my gasket is nowhere near pinched tight enough to seal I’ve got to keep cranking this bolt till it is tight enough to seal.” At the point resistance was felt is when more investigation should have taken place. There is four “indicators” that could have saved you from your current situation of distress. It may be “just an old tractor” but many parts of it were manufactured with a need for precision and to be assembled in a way that requires it to mirror a jigsaw puzzle. Only one way is the correct way for it to be assembled to provide a working unit in the end. Hope this helps.

 

[JMOR]

Ok, thanks for the response. I think I read about not doing that on a post a while back and then somehow still did it, really hurts to be dumb and stupid.

Not really dumb & stupid, but simply experience as Uses Red alludes to.

 

[That_guy]

Thanks for all the comments!
I'm pretty sure that when I took the governor off I was paying attention to where the rods connected and didn't think too much about the bolts. I simply removed them and set them aside. When reassembling I did notice some resistance with the top bolt and went back to look for another bolt thinking that it might be the wrong bolt, when I didn't find it I thought it must be the right one. Big mistake!

The other give away should have been when I tried to turn the engine over by hand and it didn't budge, I thought maybe it was just hard to turn or maybe some paint had gotten around the pulley and it would free up once started. Again, dumb move.

As they say in aviation, an accident isn't usually one bad decision but a chain of bad ones strung together. I didn't pay attention to the signs that something was wrong and just moved on thinking it was ok. Since I now get a chance to replace the gear and do it all over again, I will be paying much closer attention to what I remove and where it goes.

For those reading this post looking for info, please take my mistake as a warning about the bolts on the governor and triple check that you have the correct ones in place before you try to start the tractor.

 

[Dan]

I read and re-read this post to ensure it was not mentioned, but the only post I saw just said you used too long of a bolt. There are two bolts that hold on the governor to the housing. The top one is short as to not cause the issue you discovered, the bottom towards the outside is long and goes all the way through the cover to the other side. It is easy to mix these two up and I am always super observant when I put them back for that reason.

I always wondered why they didn't make one smaller or a different thread count to make it more apparent.

 

[That_guy]

I read and re-read this post to ensure it was not mentioned, but the only post I saw just said you used too long of a bolt. There are two bolts that hold on the governor to the housing. The top one is short as to not cause the issue you discovered, the bottom towards the outside is long and goes all the way through the cover to the other side. It is easy to mix these two up and I am always super observant when I put them back for that reason.

I always wondered why they didn't make one smaller or a different thread count to make it more apparent.

I agree, if I was engineering this part I would try to move that bolt and/or change the size/thread count to make it idiot proof.

I think this next time I'm going to engrave a "T" on the top bolt head, paint it a different color, or make it easily identifiable to ensure the correct one goes back in.

We're referring to items #26 and #27 depicted above, the top bolt (#26) is 3/8-16 x 1" and the bottom bolt (#27) is 3/8-16 x 1 3/4" according to the parts manual that I have. There shouldn't be a length issue with the bottom bolt, as Dan mentioned it goes straight through the governor mount and timing cover. I think you'll know if it is too short as it probably won't reach all the way through the hole in the timing cover. I had more than those two bolts set aside and so it wasn't a choice between "A" and "B", another bad idea.

 

[mhb@ufe]

I agree, if I was engineering this part I would try to move that bolt and/or change the size/thread count to make it idiot proof.

I think this next time I'm going to engrave a "T" on the top bolt head, paint it a different color, or make it easily identifiable to ensure the correct one goes back in.

View attachment 66004
We're referring to items #26 and #27 depicted above, the top bolt (#26) is 3/8-16 x 1" and the bottom bolt (#27) is 3/8-16 x 1 3/4" according to the parts manual that I have. There shouldn't be a length issue with the bottom bolt, as Dan mentioned it goes straight through the governor mount and timing cover. I think you'll know if it is too short as it probably won't reach all the way through the hole in the timing cover. I had more than those two bolts set aside and so it wasn't a choice between "A" and "B", another bad idea.

The early 9Ns had a stud on top instead of a bolt. If they had continued that through all of the flat head production it would have saved many cam gears and a lot of owner frustration.

 

[Robert (ID)]

You need to find the 75 tips that bruce has listed..... VERY USEFUL INFO...