I thought My 1998 Simplicity 16HP Broadmor Tractor Had Bent A Crank – The Real Problem Was A Surprise!!

We bought our Simplicty 16HP Broadmor tractor back in 1998 mainly because my dad had a Simplicity that he kept running for almost 30 years. So here are in on 2019 and the tractor is starting to show its age plus the dealership is long gone so a lot of self-service and tinkering happens now.

I was mowing leaves a few weeks back on out acre and a half property when I had to turn the tractor off to pick up branches and move stuff around. I went to start it up and immediately heard thud, thud , thud, thud … so I turned the tractor off. Oh crap … the last time I heard a sound like this a car had bent a rod. I immediately checked the oil and it was almost empty.

Now I was really pissed off at myself. I knew it was burning oil but why had I let it get so low? I thought it had a low oil level protection device to stop it running … Needless to say,I was mad and I knew the fault was all mine. It was the worst possible time also – we simply could not afford to replace the tractor.

So, I filled the oil and figured I would run it until it failed. I had to get the leaves done and that’s just what I did. I ran it for another hour and put the tractor away while feeling like an idiot the whole time.

A week later we had a ton more leaves on the ground so I went to get the tractor out of the shed fully expecting it not to start. Much to my surprise, it did start and I made it half way through the yard when I had to turn it off to eat lunch with my wife.

When I went back out I started it up and it was really clanging away and the tractor was really vibrating but the engine sounded good. I turned the engine off and thought about it. I assumed it was a rod because of the low oil but what if that was not the problem?

The exhaust was tight and not rusted out. The oil level was good. So I started it with the top open and put my hand on the engine to feel for vibrations and the thudding stopped …. Holy Crap???? I took my hand off and it started thudding. Put it on and it stopped. I turned the ignition off and found that I could move the engine on the frame!!

I looked under the frame and one motor mount screw was in the hole but loose. Another was cocked in the hole ready to fall out and the other two werre missing. As luck would have it, I found one screw in the yard. Looking at it jogged my memory of a screw I found a few weeks earlier and couldn’t figure out where it came from. To this day I am not sure if I threw the screw out or tossed it somewhere in my shop – I thinkI threw it out.

So, after almost 21 years, the motor mount screws came loose. It never occured to me to check them. Now, here’s what I want to share with you – the screws are M8 diameter x 1.25 pitch x 30mm long. You can find them at hardware stores, etc. The original bolts also have a washer and lockwasher. I bought the replacement and was good to go.

Say hello to Mr. replacement bolt, washer and lock washer. After torquing things down, the tractor was running smooth again. Duh.

The torque spec is 40 foot pounds and if you want to never deal with them again, put a bit of blue loctite on the screws. Note, I would highly recommend that if the engine is hot, let the engine cool down before torquing on aluminum. I’ve watched threads strip on hot aluminum way too many times and have learned to be patient although a floor fan pointing at the engine will help it cool down a lot faster.

When I started the tractor again after replacing the bolt and torquing down all the bolts it was a huge relief to see and hear the tractor operating normally. I figured it was a good story to share.

Moral of the story – don’t assume and check before you jump to a conclusion. I did make a big assumption based on the sound and freaked myself out before I started the process of elimination that I should have started with. I hope this helps you out.


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