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vibration


buckdan

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Hello,

Once again I am experiencing vibration on my DA 1920,1691020.

What variables come into play? Driveshaft or motor mounts? I am also hearing a squealing sound coming from the front pto clutch not engaged, when I engage front pto, sound disappears. Do I have a bad bearing causing the vibration? Don't know what else to do, keep tightening the motor mounts or take apart the the front pto clutch? I hope I can omit the step on removing the driveshaft.

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Try to isolate where the sound is coming from and its frequency. Is it at motor RPM? Then could be a bearing or even just something touching a shaft or motor or loose hood. Does the whole machine shake with the vibration? Is it the same when in neutral or does it change when in gear? Does it change or increase/decrease in amplitute/sound with engine speed? If it is directly tied to the engine and its speed, it sounds like something is out of balance or misaligned or a cylinder on one side is not firing regularly. Hope you find the source and that it's an easy fix.

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Universal joints seem fine, although there is some play when I move it side to side.

When I change into gear vibration is not as bad. Steering wheel has some vibration. I have noticed the front wheels vibrating at low idle. Short story, when I put a load on it, engage the mower, vibration is less noticeable.

Now I am stressed, I hope it is not a cylinder firing irregularly!

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It's hard for me to try to help without seeing or hearing your tractor - and maybe I couldn't if I did. It's like a doctor getting a call that "my kid has a rash, what should I do?" I'm not sure if you have a vibration of the sheet metal or, more likely. a shaking of the engine making the whole machine or parts of it move. Does it still have full power or is a cylinder misfiring, maybe because of a bad spark plug. Can you see the engine shake at idle? Did you try removing the plug wires or shorting them out alternately one at a time to see the effect on engine operation and possibly see which side has a problem?

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I know its hard to tell from me explaining the symptoms. I could try taking a video with sound, thats if I can upload to this site.

What I am thinking I have shaking of the drive shaft. Or the bearing at the front pto clutch, is that possible? I do have full power, it revs to about 3400 at full throttle and seems to be running smooth. I have taken the compression readings about month ago showing 100 psi at the #1 cylinder and about 98 psi on #2. Also about 3 months ago I had to pull the engine and repair the flywheel, all the magnets were broken to fix the charging system. Bought a used flywheel, replaced all the motor mounts. Fired her up and noticed a lot of vibration and took a look at the driveshaft and it was wobbling, immediately I shut her down. So what i did was loosen the motor mounts and push the engine as far as it would go to the rear of the mounting plate. tighened the bolts down again. Fired her up she was running very smooth and no vibration, problem solved so I thought. Began using the tractor months later and vibration is back.

Did I not tighten the motor mount bolts tight enough? should I retighten with full torque? Or did something else come into play here that I am not aware of?

My apolgies for the lenghty explanation, hopes this helps anyone here to understand this Deutz Allis's lashing out at me.

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Take a video and post it to YouTube. Then share the link here on this thread and we can see and hear the symptoms.

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Since it was OK before the engine was pulled and the engine seems smooth now and you had it all running smoothly once after reinstalling, it sounds possible the mounts didn't hold the engine/driveshaft alignment in place or the driveshaft is wobbling because of loose bearings/joints. Have you tried loosenig the mounts again, make sure it all lines up and turns well and then torqueing to specs?

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I have had lots of trouble with vibration in my M20 in my 1920. I just take out the rubber mounts now, line up the front pulleys and bolt the engine in direct. Haven't had a problem since.

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Interesting solution.

But my thinking is the motor mounts job is to isolate vibration, am I correct? Or is it to align the engine in the correct position with the front pulleys and drive shaft to the transmission.

I'll try loosening the mounts again. I am torqueing 25 ft.lb's.

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Yes, That's what they're supposed to do, the main concern is the belt alignment. When they started putting Command engines in these machines, they quit mounting them on the rubbers. In my opinion, the Magnum engines don't vibrate enough to warrant the rubber mounts, I cant notice a difference without them except ironically, the vibration is gone.

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Maxtorman, thanks for your info on motor mounts. Next time I have to pull the motor I'll try intalling without rubber mounts.

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It sounds like you have pulled the motor before. When did the vibration start before or after you pulled the motor. Could it be that something is not lined up corrected, or the drive shaft is too long or set net correctly?

Think about when the vibration started and what type of repair / maintenance you did last.

Rick.....

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I have pulled the motor before. When I bought it, it was missing a rubber mount and was vibrating. The main reason I pulled it was to reinstall the stator, the conductors coming off the stator were severed completley off at the flywheel.

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