Gravely gear trans noise

[daugen]

my beloved 8199G has only 800 original hours on it, but it seems, and I might just be imagining this, that the trans is getting noisier and noisier. Never quiet, but
never expected it to be.

Would adding a trans additive, say with something extra slippery in it, be helpful? I wonder about common oil supplies,and the slippery stuff getting where it shouldn't be. Clutches are
external, so no worry about that. Pto? is it dry?

I've used Tufoil and other friction reducers before, wonder if that would help this 1986 trans. Trans oil changed several times in recent years, so it's on spec.

 

[RichardTX]

The PTO clutch is a wet clutch. Adding anything to reduce friction will usually muck with the PTO clutch usually causing it to slip. Once it starts to slip then it quickly wears out. Changing a PTO clutch is no 5 minute job nor is it cheap. To put in a new PTO clutch requires about 8 hrs of work (for someone that has become good at it) and about $300 in parts.


To extend PTO clutch life, engage the pto while the tractor is at an idle.

I would suspect the direction clutch bearings first. Those bearings spin all the time when the tractor is moving.

Can you be more descriptive of the noise you are hearing? When does it occur? Is it any better in reverse, neutral, etc.?

It is a good idea to change the trans oil yearly or every other year if stored in a garage. While the oil does not get dirty luike the engine oil does, it does pick up contaminants like moisture. Around here, trans oil lasts about 18 months and then it starts getting milky from condensation.

 

[daugen]

Can you be more descriptive of the noise you are hearing? When does it occur? Is it any better in reverse, neutral, etc.?
The best way to describe it is as whirring and whining when in motion. Quiet at idle.
Almost wonder if putting in a thicker oil than 30W might calm things down but don't want two different oils in the tractor if I can avoid it.
I changed the trans oil when I got it and a year ago.
I'm not expecting this gear trans to be quiet. It doesn't need to be.
But if the increased noise is my canary in the mine, I'd like to pay attention if need be.
thanks

 

[RichardTX]

I would check the direction clutches and the direction clutch bearings. They should be removed and the splines greased yearly anyway.

 

[daugen]

I would check the direction clutches and the direction clutch bearings. They should be removed and the splines greased yearly anyway.

Richard,
I'm rereading this. Do I have to remove the clutches? I keep that spline greased/oiled a lot more often than yearly.
May I assume the direction clutch bearings are external, since the clutch is, and not crazy to get off/replace? Sounds like something I could do, but I'm not
getting inside that trans case, no way. Way over my ability. thanksDrew

These riders are not quiet machines. Most of the time the trans noise is masked, unless I'm just traveling somewhere with pto off. And yes, I engage at low rpm.
The gravely rarely stalls doing that. My JD lawn mower if not perfectly warmed up will stall very quickly if the rpm is not high enough when pto engaged electrically.
I sure like slowly but surely engaging the pto lever on the Gravely, one can "feel" whats going on. Seems analagous to popping the clutch in your car, for those who still have clutches,
at 5000 rpm and wondering why the clutch needs to be replaced after awhile. Those instant on electric pto clutches gives me the willies, and they are everywhere. Kind of a game seeing
how low an rpm I can go on my LX280, with a very nice Kawa 18 inside. The Gravely doesn't seem to care. and it's amazing all that gearing starts spinning around so easily.
I keep the thing well lubricated...

I can't imagine not having a Gravely rider. What a great machine, a bit crude but tough as nails. This is my second one, I bought a new 16G back in the mid 80's I think, and my friend just sent me a pic
he dug up of our using it at his cabin in the Catskills. Lots of rides for the kids; my friends four year old daughter is quite happily sitting in the trailer. I didn't keep one pic of that tractor, glad my friend kept this one.

I bought the first Gravely to use to mow the lawn on our farm, while I was living there, having come home after ten years of working outside of the area. 7 acres of lawn, huge job to mow and trim, and it took five years
of "helper" use of that mower, after I sold it back to the family when I moved out, to blow up the Kohler K engine in it. Or was it a Magnum? Regardless, we weren't aware of how easily those engine fins get clogged back then,
and I bet a combo of low oil and a hot engine just did it in. Sure can't blame the mower, which is usually the case. Hit a stump, pay the price, don't blame the machine...

pleased to report I've lost over fifty pounds from this pic. Sure was needed... And yes, the beard went too. My wife did not like the mountain man look, so ok.

hmm, after zooming in on this pic, seems the old rider was an 8163G, but that had a B&S, which is wrong, I definitely had a Kohler. How are your eyes? 1986 I believe. But the 16G came in 1988.
Hmmm, how did I get a Kohler on that?

 

[RichardTX]

Richard,
I'm rereading this. Do I have to remove the clutches? I keep that spline greased/oiled a lot more often than yearly.
May I assume the direction clutch bearings are external, since the clutch is, and not crazy to get off/replace? Sounds like something I could do, but I'm not
getting inside that trans case, no way. Way over my ability. thanksDrew

It isn't hard to remove the clutches. Remove one clevis pin, and two nuts and the assembly slides off. It is a little tricky getting it back on without dropping the 3 rollers but a little grease will hold them in place.

The PTO clutch is internal to the transmission but the direction clutches are external.

Replacing the bearings on the direction clutches is not difficult. A bench vise, 3 small C clamps and a pair of snap ring pliers is all that is really needed.

The bearing is a double sealed 6208 with snap ring.

Congrats on the weight loss. I also gained a bunch of weight a few years back and then decided to do something about it. It took a while but got rid of most of it. That last 10 lbs just never seems to go away no matter what I do.

The Gravely transmission has straight cut gears and that is why they are noisy. You might try changing the oil to a 20w50 oil. It might quiet it down a little.

The Magnum engines are OK but the parts prices are out of sight. $600 for a M18 crankshaft is just insane. It gets worse. A M20 crankshaft is $800. I am out of the Magnum business. I dumped all the Kohler engines on my 4 wheel Gravelys in favor of 24hp Onan engines. The engine swaps were not hard but some of the engines required a crankshaft swap. The two new crankshafts I bought for the Onan 24hp engines cost me $125.00 each.

Anyone who says Onan parts are high hasn't had to buy any parts for a Kohler Magnum.

 

[daugen]

I'm not sure, but I think they replaced the bearings when I had both the forward and reverse clutches replaced. Certainly would make sense to...
so maybe this noise is something else. I guess the only way to do this "scientifically" is to run the machine and record the sound, with what, I guess my camera.
I also have a sound meter.....hmmm.
I've never posted on YouTube, wish there was a way of posting small stuff here, but even for short movies I find I create humongous files. Likely a way to dial it down,
one of those mystery buttons...

 

[RichardTX]

The sound meter will likely be of no benefit. The sound of the engine usually overwhelms everything else.