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Grinding... Throw Out Bearing?

Posted: Wed Jul 03, 2013 5:52 pm
by AgTires4295
This thread stems from another thread that I had started. I wanted to break away and keep from contaminating the Rough Idle thread.

On the '54 Cub, I have some moderate to severe grinding while in motion. I knew about it before but now it's been brought to my attention in another video and it's eating at me a little. I can turn the Cub on and hear faintly at a low idle the grind. When I engage the clutch, it slows and stops. When the clutch is released, it starts again. It was hard to tell where exactly it was coming from. Ray (Smokeycub) had mentioned in the other thread about the throw out bearing (I had no clue what this was). After combing other threads, I got the idea and went out to see what I could see. I popped open the bell housing cover and there was the zerk. Fitted and filled with grease, no problem while keeping my fingers crossed. I made another vid (https://www.youtube.com/watch?v=fx3RMG- ... ata_player) and its only better in neutral, SO I think greasing the TOB was a great idea anyway since it needed to be done.

When placed in gear (any gear), as soon as the clutch is released, the grinding starts and becomes more pronounced with any increase in speed and/or resistance (for example the resistance of driving up the small hill).

I became increasingly aware of the grinding and while I didnt move from my seat, I believe it is coming from the gear box. This blows my mind because last year I flushed and replaced the trans oil in hopes that it would cure the grind. Any ideas?

Re: Grinding... Throw Out Bearing?

Posted: Wed Jul 03, 2013 7:00 pm
by Bill Hudson
Grinding in any gear, coming from the transmission sounds like either, or both, of the input and output bearings are toast. Best approach is to park it -- now. Other, more knowledgeable, people will be along soon to offer expert advice.

Bill

Re: Grinding... Throw Out Bearing?

Posted: Wed Jul 03, 2013 7:20 pm
by tst
sounds like trans bearings are toast, needs to come apart!
Tim

Re: Grinding... Throw Out Bearing?

Posted: Wed Jul 03, 2013 8:22 pm
by AgTires4295
Great... :?

Re: Grinding... Throw Out Bearing?

Posted: Fri Jul 05, 2013 10:29 am
by Smokeycub
It's really hard to differentiate in the video. Like I mentioned in your other post, driveline. i.e. trans bearings or final drives. Whichever it is (or combination there of), it sounds dry.

Re: Grinding... Throw Out Bearing?

Posted: Fri Jul 05, 2013 12:10 pm
by Matt Kirsch
If it were the throwout bearing, greasing it would only have a temporary effect at best.

The throwout bearing would be grinding because it was making constant contact with the clutch release fingers on the pressure plate. That's bad. It means the clutch pedal free travel is completely gone, or worse, the throwout bearing is actually pushing down on the pressure plate fingers and causing the clutch to be partially released all the time.

You would be able to see the throwout bearing making contact with the clutch fingers through the access hole if this were the case.

Two reasons for this:
1. Pressure plate and/or clutch disk shot.
2. Really poorly adjusted clutch pedal free travel.

Re: Grinding... Throw Out Bearing?

Posted: Fri Jul 05, 2013 12:55 pm
by Smokeycub
Matt Kirsch wrote:If it were the throwout bearing
In his video it seems to only make the noises while in gear and the clutch out. No noise with the clutch depressed, or in neutral with the clutch out. It really sounds to me (hard to differentiate) like trans bearings or the final drive(s). ...and again something sounds dry and badly needs gear oil at the least. Like the other said, could be teardown and replacement time.
AgTires4295 wrote:last year I flushed and replaced the trans oil in hopes that it would cure the grind. Any ideas?

Did you check the final drives for gear oil?

Re: Grinding... Throw Out Bearing?

Posted: Fri Jul 05, 2013 6:08 pm
by AgTires4295
Ive checked the oil for the trans. Maybe I missed something with the final drive. When I did the trans oil 2 years ago, I added a little too much and it began to leak through the seals and drip at the brake housing. Before and after, its been the same grinding sound. I just did a short clip https://www.youtube.com/watch?v=UwbX6eF ... ata_player) where I slightly push the PTO pully with my hand and it make the grinding noise. Not sure if it's related or not but it may be another symptom that may help somebody to diagnose my problem.

Re: Grinding... Throw Out Bearing?

Posted: Sun Jul 07, 2013 10:43 am
by Smokeycub
There are two final drives, one on each side of the transmission/differential. The finals gear oil is separated from the brake housings by seals on each side. If the trans seal(s) are bad the excess gear oil from the trans will leak down to one or both of the brake housings depending on the condition of the seal(s) causing the leak you noticed on the one side.
AgTires4295 wrote: it began to leak through the seals and drip at the brake housing

You can check the finals from underneath, just above the finals oil pans. The fill/level plug is the square drive plug just below the #2 in the diagram below. It will be behind the mule drive on one side and behind a mower bracket on the other, so you'll need to remove those items to check the oil level. You don't need to remove the pans unless you want to clean and inspect them for debris/grindings.
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The brake housing should be dry (no oil) and is sealed off from the trans/differential and the finals.

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Check it out and let us know what you find. Hope that takes care of it for you.

Re: Grinding... Throw Out Bearing?

Posted: Sun Jul 07, 2013 3:46 pm
by John *.?-!.* cub owner
I have one similar though not as bad (my loader cub), that I believe is either the reverse idler or bearing on the pinion shaft (bottom shaft in the transmission). Jack both rear wheels up, and turn them one at a time, and also together. If it only makes noise when both wheels are turning the same way, that means it is only making noise when the pinion shaft is turning, which also turns the reverse idler any time the pinion shaft turns.

Re: Grinding... Throw Out Bearing?

Posted: Sun Jul 07, 2013 10:47 pm
by AgTires4295
Thanks Ray--will hopefully be able to dig into that tomorrow. Keping my fingers crossed that those are the troubled spots. If in fact low, is it the same oil as the gear box?

Re: Grinding... Throw Out Bearing?

Posted: Mon Jul 08, 2013 7:53 am
by Smokeycub
Yes - the manuals call for 90wt gear oil.

Re: Grinding... Throw Out Bearing?

Posted: Thu Jul 11, 2013 8:19 pm
by AgTires4295
Spent about 2 hours disassembling and cleaning to get to the rear axle housing. It was indeed needing attention. Both sides had almost nothing in them! I was hoping this was the cure but after putting it all back together, it wasnt. I am starting to think it's PTO related in that it makes the grind with the PTO engaged while in neutral also. I think I'm going to drain the trans oil and start again with that in hopes that I have been running incorrect levels and the oil isn't getting thrown around like it should be.

On a positive note, I rotated the rear tires around and flipped them to give me a wider stance for cutting grass on the hills. Now I need to tackle the front but that looks like it's going to he a headache. I gave it 5 minutes and went inside.

Re: Grinding... Throw Out Bearing?

Posted: Fri Jul 12, 2013 8:30 am
by Smokeycub
Sorry to hear the gear oil in the finals wasn't the problem. Sounds like they needed the attention anyway and now you know that's not the problem. Did you try what John suggested while you had the tractor jacked up?
John *.?-!.* cub owner wrote: Jack both rear wheels up, and turn them one at a time, and also together. If it only makes noise when both wheels are turning the same way, that means it is only making noise when the pinion shaft is turning, which also turns the reverse idler any time the pinion shaft turns.

The reverse idler is inside the transmission. Sadly, in any event it seems the noise has now been isolated to the trans and requires a teardown.