What oil to use in an older 12 hp Kohler K301 S engine?

I've had several K series Kohler's over the years.
If they are pretty "fresh and tight" I run Amsoil small engine 10w30 or 10w30 hdeo (rotella or delo)
A couple I've had that had a little blow by I ran 15w40 in them and that worked well.
 
Hello,
I've just purchased a 5665 model Gravely walk-behind tractor, 1984 year. 12 hp Kohler K 301 S engine, single cylinder gas.
I would like advice on the best oil to use. No oil filter on this older engine. Air cooled.
Original manual says 30W above freezing, 10-30 below freezing, and an SG or SH classification, which are now obsolete.
Should I stay with those weights? I will change religiously at 25 hours maximum.
Any advice on the best brand, whether regular or synthetic, etc.

Thank you so much for your help, Peter

What location? weather?

With a 25hr interval, I'd use whatever heavy duty 10w30 was available locally. For example:

If it were mine, I'd use Delo, Rotella, or Delvac in 5w40 and thumb my nose at their ancient recommendation.
 
regarding oil for my 5665 Gravely with a Kohler K301 engine.
Lots of good recommendations here, thanks !
As I have gallons of Shell Rotella T4 15w-40 on hand already for my diesel trucks, I think I will go with this.
It also has a high zinc content.

Am I correct in assuming that this oil will also be OK in the transmission?

thanks, Peter
 
regarding oil for my 5665 Gravely with a Kohler K301 engine.
Lots of good recommendations here, thanks !
As I have gallons of Shell Rotella T4 15w-40 on hand already for my diesel trucks, I think I will go with this.
It also has a high zinc content.

Am I correct in assuming that this oil will also be OK in the transmission?

thanks, Peter
Yes that will work great in the transmission. It's what I currently have in the transmission of my Commercial 10A.
 
Hello,
I've just purchased a 5665 model Gravely walk-behind tractor, 1984 year. 12 hp Kohler K 301 S engine, single cylinder gas.
I would like advice on the best oil to use. No oil filter on this older engine. Air cooled.
Original manual says 30W above freezing, 10-30 below freezing, and an SG or SH classification, which are now obsolete.
Should I stay with those weights? I will change religiously at 25 hours maximum.
Any advice on the best brand, whether regular or synthetic, etc.

Thank you so much for your help, Peter
For the transmission oil in my 5665 Gravely, I think my Shell Rotella T4 15W-40 would be OK. It has a JASO MA/MA2 rating, so shouild be good with the wet clutches. I don't know much about JASO ratings, but understand that it is formulated for higher friction for motorcyle wet clutch applications.
thoughts?
 

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Yes, Rotella 15w40 is very popular in wet clutch applications like motorcycles or ATV transmissions. It should work great in the Gravely. I've been running it in the transmissions of my Gravely tractors for quite a few years now with all sorts of different tractors over the years, 1940's L models, Kohler powered tractors, etc.

One thing I've noticed on the Kohler powered Gravelys is since the transmission oil is not shared with the engine oil like the older L models (with oil filter), the transmission oil seems more likely to have moisture stay in the oil if it does not get up to temperature often.
IMG_3103.JPG
 
Yes, Rotella 15w40 is very popular in wet clutch applications like motorcycles or ATV transmissions. It should work great in the Gravely. I've been running it in the transmissions of my Gravely tractors for quite a few years now with all sorts of different tractors over the years, 1940's L models, Kohler powered tractors, etc.

One thing I've noticed on the Kohler powered Gravelys is since the transmission oil is not shared with the engine oil like the older L models (with oil filter), the transmission oil seems more likely to have moisture stay in the oil if it does not get up to temperature often.View attachment 143141
Thanks jeepman ! reassuring comments. It's interesting, but I have the orignal manual for this 1984 year 5665 tractor, and it says nothing about how often to change the transmission oil. Just says check the level every 100 hours and add oil if necessary.
What do you recommend?
 
Thanks jeepman ! reassuring comments. It's interesting, but I have the orignal manual for this 1984 year 5665 tractor, and it says nothing about how often to change the transmission oil. Just says check the level every 100 hours and add oil if necessary.
What do you recommend?
I would change it every 50-100 hours depending on use. Mine is run in dusty environments (brush mowing) and snow removal, so I usually do it every other year. I don't think the oil had ever been changed before I picked up this particular tractor 3 years ago, and there was some gear wear when I had it apart to rebuild the engine. I also use 15w40 in the Kohler.
 
I would change it every 50-100 hours depending on use. Mine is run in dusty environments (brush mowing) and snow removal, so I usually do it every other year. I don't think the oil had ever been changed before I picked up this particular tractor 3 years ago, and there was some gear wear when I had it apart to rebuild the engine. I also use 15w40 in the Kohler.
that interval is about what I was thinking. I still do find it strange that there is no mention of transmission oil change in the manual.
They even say to clean the battery at 100 hours...!
 
Hello,
I've just purchased a 5665 model Gravely walk-behind tractor, 1984 year. 12 hp Kohler K 301 S engine, single cylinder gas.
I would like advice on the best oil to use. No oil filter on this older engine. Air cooled.
Original manual says 30W above freezing, 10-30 below freezing, and an SG or SH classification, which are now obsolete.
Should I stay with those weights? I will change religiously at 25 hours maximum.
Any advice on the best brand, whether regular or synthetic, etc.

Thank you so much for your help, Peter
10W-30
 
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