Oil Leak

Mr Bob · #1 01-20-2019, 04:49 PM

Have another dumb question about oil level in a cub 149. Seems the engine I rebuilt has a very slow oil leak coming from the rear center of engine. It leaked a small amount after about 15 minutes of being parked and running. Put it back in garage and a couple days later noticed a couple drops of oil on the floor under back center of engine. Cleaned the drops of oil up and has not leaked while not being run. Now to my dumb question!!! Is the oil level above the place where oil pan meets bottom of engine and is the oil level inside engine high enough to reach bottom of crank shaft while on level pavement? This engine did not leak after being put together and ran for half hour before re-torquing head. All input will be greatly appreciated. Have a great day
Bob

dodge trucker · #2 01-20-2019, 07:13 PM

What are you considering the rear side of the engine? To me the flywheel side has always been the front.
On a 1200 that I rebuilt I chased an annoying oil leak, redid the breather, no dice. Redid the pan gasket, still no success. It wound up with a hairline crack in the pan right in the corner diagonally across a mount bolt that holds it to the block. After I redid the pan gasket the 1st go round, I left the engine hang from the cherry picker, and filled it to capacity with oil. Never started it during this time. And there it was. I had helicoiled the mount bolt holes that hold the engine to the tractor, it wasn't that, it was well inboard of the mount ear. PITA to find but I finally did.
The leaker was aluminum, I had a cast iron pan here that I was hoping to use on something else but wound up having to plop it on to that engine. No more leaks

Mr Bob · #3 01-20-2019, 07:43 PM

Thanks for the reply dodge trucker. To me the fly wheel end has always been the rear of the engine. To each his own. I put a cast iron oil pan on it when I rebuilt it. Sand papered it on glass before putting it on engine. It would have been better, imo, if IH would have used at least 6 pan bolts. I really feel it is the rear main seal leaking. The oil dripped down center of fly wheel side of engine. I was thinking that if the oil level was above bottom of rear seals, it should leak while parked and not just when running. I had the Kohler shop manual and went by the instructions, although I can't remember the instructions now. Maybe will learn more by tomorrow. Thanks again and have a great day.
Bob

PaulS · #4 01-20-2019, 10:21 PM

If you have oil leaking from the flywheel end of the engine my suggestion is to check the rear oil seal. That seal can leak while the engine is running but may or may not leak with the engine off. The drive shaft turns inside the oil seal but with the engine off the shaft stops turning and possibly the seal is still in good enough shape to stop leaking. The seal is not expensive so I would check it first.

sawdustdad · #5 01-20-2019, 10:58 PM

The oil level in the pan does not come up to the oil seal. So it would leak when running but not at rest (once any remnants drain down).

Oil seals can leak if the crank has a groove worn in it where the seal runs, or if the seal is not seated properly (square) to the shaft.

I've heard of a variety of solutions, not sure which ones would apply here--seat the seal so it does not hit a worn groove, sleeve the shaft so the groove is under a smooth sleeve, repair the shaft to remove the groove, or use a different seal geometry that puts the lip at a different point so it does not sit in the groove.

Replacing the seal is doable without tearing down the engine, but flywheel's got to come off.

Gompers · #6 01-21-2019, 12:11 AM

Quote:

Originally Posted by Mr Bob

Thanks for the reply dodge trucker. To me the fly wheel end has always been the rear of the engine. To each his own. I put a cast iron oil pan on it when I rebuilt it. Sand papered it on glass before putting it on engine. It would have been better, imo, if IH would have used at least 6 pan bolts. I really feel it is the rear main seal leaking. The oil dripped down center of fly wheel side of engine. I was thinking that if the oil level was above bottom of rear seals, it should leak while parked and not just when running. I had the Kohler shop manual and went by the instructions, although I can't remember the instructions now. Maybe will learn more by tomorrow. Thanks again and have a great day.
Bob

Well you can say that, but if you order a rear seal for a kohler engine, you'll get the wrong part. The front of the engine is the flywheel, and the rear of the engine is the PTO. The rear of the engine is the front of the tractor, and vice-versa.

I'd highly suspect the front seal (or rear seal as you refer to it) as well.

finsruskw · #7 01-21-2019, 08:42 AM

Cast iron pans will crack as well.
Got one from e-bay for the 149 loader project and it leaked all over the freshly restored rig.
Turned out to be a hairline crack by one of the bolts.
I suspect it had been run maybe w/only one bolt for a while in a previous life.

Mr Bob · #8 01-21-2019, 09:42 AM

First off, thanks for all the advise. Second, dodge trucker, you are correct as per the Kohler manual. The fly wheel end is the front. Back in the sixty's, on a 283 Chevrolet engine the fly wheel end was referred to as the rear of the engine. Now back to my problem. The Kohler manual states that the front seal goes in 1/2" from outer face. The rear seal goes in 1/8" from face. Hope I have that correct. I remember measuring the seals as I installed them. Is it possible to have the depth of the seals reversed? Guess I will pull the engine later on to possibly see the problem.Thanks again for all the help from the members of this awesome forum. Have a great day.
Bob

Gompers · #9 01-21-2019, 10:41 AM

Quote:

Originally Posted by Mr Bob

First off, thanks for all the advise. Second, dodge trucker, you are correct as per the Kohler manual. The fly wheel end is the front. Back in the sixty's, on a 283 Chevrolet engine the fly wheel end was referred to as the rear of the engine. Now back to my problem. The Kohler manual states that the front seal goes in 1/2" from outer face. The rear seal goes in 1/8" from face. Hope I have that correct. I remember measuring the seals as I installed them. Is it possible to have the depth of the seals reversed? Guess I will pull the engine later on to possibly see the problem.Thanks again for all the help from the members of this awesome forum. Have a great day.
Bob

I don't think those depths are super critical, as long as the seals are both still in contact with all the sealing surfaces, but it's certainly possible that you may not have the front one driven in far enough.

sawdustdad · #10 01-21-2019, 05:46 PM

Quote:

Originally Posted by Mr Bob

First off, thanks for all the advise. Second, dodge trucker, you are correct as per the Kohler manual. The fly wheel end is the front. Back in the sixty's, on a 283 Chevrolet engine the fly wheel end was referred to as the rear of the engine. Now back to my problem. The Kohler manual states that the front seal goes in 1/2" from outer face. The rear seal goes in 1/8" from face. Hope I have that correct. I remember measuring the seals as I installed them. Is it possible to have the depth of the seals reversed? Guess I will pull the engine later on to possibly see the problem.Thanks again for all the help from the members of this awesome forum. Have a great day.
Bob

I just put the seal in the bearing plate on a K241 earlier today. it was 1/8" in or so. The bearing plate would be the flywheel, or "front" of the engine. The rear seal goes in deeper, but I agree, it's not critical. It's more important that it's square to the crankshaft.

I don't think it's possible to put the front seal in 1/2 inch. There isn't that much room on the bearing plate bore. At least not on a K241 or any battery ignition K series.