Leaking lower seal is finally too bad to ignore.

[Elkins45]

The lower oil seal on my 22hp B&S V-Twin has been leaking for 3-4 years now. I've been parking it over a pan and topping off as needed but now it's leaking enough that it's noticeably smoking from oil being flung onto the muffler and manifold, and right after I shut it off it drips 2-3 ounces of hot oil before it cools down.

I have been told it's possible to stand the mower up vertically and replace the seal by running a couple of self-tapping screws into the old one and pulling it out. That would save both the trouble of removing the engine and also the cost of replacing the crankcase gasket.

Anybody here ever tried this? I think I'm willing to give it a go because if I screw it up I'm really no worse off than I would have been anyway.

 

[joegreen]

I have run drywall screws into seals before. Works most of the time. Just make sure you get the screws into the metal of the seal

 

[vw7674]

sounds like fun.
I'd go with one drywall/decking screw, & a vise grip to tug on it .

 

[mk378]

There are also hook style tools to remove seals from the outside:

https://www.amazon.com/Lisle-56750-Seal-Puller/dp/B0002SRCKG

You may still want to remove engine for better access. It's only 4 bolts from the bottom, the fuel hose the harness plug and the throttle cable.

 

[wag123]

The lower oil seal on my 22hp B&S V-Twin has been leaking for 3-4 years now. I've been parking it over a pan and topping off as needed but now it's leaking enough that it's noticeably smoking from oil being flung onto the muffler and manifold, and right after I shut it off it drips 2-3 ounces of hot oil before it cools down.

I have been told it's possible to stand the mower up vertically and replace the seal by running a couple of self-tapping screws into the old one and pulling it out. That would save both the trouble of removing the engine and also the cost of replacing the crankcase gasket.

Anybody here ever tried this? I think I'm willing to give it a go because if I screw it up I'm really no worse off than I would have been anyway.

Are you positive that it is the lower seal? I don't think so. If the lower seal was leaking it would leak ALL of the oil out over the course of a few days. Furthermore, the oil is leaking on top of the mower chassis, not below. B&S V-Twins are notorious for blowing the crankcase gasket adjacent to the cylinders. When this happens the leak will do as you describe, and it blows oil right at the exhaust when it is running. You are going to have to pull the motor to fix this, a little time consuming if you haven't done one of these repairs before, but not a big problem or rocket science (just a nuts & bolts repair). Cleaning up the mess that the oil made will take longer than the actual repair.

 

[tnt_motorsports]

On my Deere LT150 I can remove the deck and get under the mower and remove the crankshaft pulley. This would allow you to confirm the crank seal is leaking. My Kohler was leaking and it blew oil all over the bottom of the frame and engine. I changed it while the engine was out but IMO, I could have changed it in the mower.

Just my $0.02

 

[jeepman3071]

Definitely try the screw method, I've done a few of these using that and it works pretty well. Also check your head gaskets, Briggs engines are famous for blowing the head gasket which can cause a bunch of issues including pressurizing the crankcase.

 

[Elkins45]

Are you positive that it is the lower seal? I don't think so. If the lower seal was leaking it would leak ALL of the oil out over the course of a few days. Furthermore, the oil is leaking on top of the mower chassis, not below. B&S V-Twins are notorious for blowing the crankcase gasket adjacent to the cylinders. When this happens the leak will do as you describe, and it blows oil right at the exhaust when it is running. You are going to have to pull the motor to fix this, a little time consuming if you haven't done one of these repairs before, but not a big problem or rocket science (just a nuts & bolts repair). Cleaning up the mess that the oil made will take longer than the actual repair.

No, it’s the lower seal. The oil drips onto the pulley and gets flung everywhere when it spins.

 

[Lubener]

No, it’s the lower seal. The oil drips onto the pulley and gets flung everywhere when it spins.

I had the same issue with my B&S. Oil was dripping onto the pulley, ruining the belt. Sure looked like the seal leaking but it wasn't. You won't know for sure until the engine is completely degeased. Mine was leaking from the gasket which is between the sump and crankcase. I wouldn't have found it without a very small mirror. The case was warped.

 

[FowVay]

Be sure to take the battery out of the mower before flipping it up on its end. Chickanic had a video of a mower that was ruined when the customer flipped his Snapper onto the tail rails to access the blade and the battery leaked its contents all over the engine.

I've used screws, nail punches and even small screw drivers to pry and gouge old seals out of their seats. I never found the screw technique very rewarding. I like the small, flat blade screwdriver method. Just don't go crazy and scratch the crank or damage the housing.

 

[wag123]

I had the same issue with my B&S. Oil was dripping onto the pulley, ruining the belt. Sure looked like the seal leaking but it wasn't. You won't know for sure until the engine is completely degeased. Mine was leaking from the gasket which is between the sump and crankcase. I wouldn't have found it without a very small mirror. The case was warped.

This is what I was talking about.
I reiterate, if the lower crankshaft seal is leaking, all of the oil will leak out of the engine when it sits.

 

[Elkins45]

I had the same issue with my B&S. Oil was dripping onto the pulley, ruining the belt. Sure looked like the seal leaking but it wasn't. You won't know for sure until the engine is completely degeased. Mine was leaking from the gasket which is between the sump and crankcase. I wouldn't have found it without a very small mirror. The case was warped.

Well, I guess it's time to get some rags and a couple of cans of parts cleaner.

 

[repairman54]

I just had to replace an axle seal in a Tuftorq transaxle. Screw method doesn't work in seals without metal that goes into the seal flat around the lip. Had to pry out with screwdrivers. I guess a seal tool will be my next tool purchase.

 

[mk378]

customer flipped his Snapper onto the tail rails to access the blade and the battery leaked its contents all over the engine.

Snapper had a lot about that in the owner's manual. Tipping the mower up on its back end was a recommended practice. But they came with a special battery with the vents all the way on one side (which would be the top when stood on end) so that it would not spill.

 

[Elkins45]

I spent $123 on five gaskets and an oil seal today. It’s gonna suck if this thing doesn’t start after I install them.

 

[wag123]

I spent $123 on five gaskets and an oil seal today. It’s gonna suck if this thing doesn’t start after I install them.

There shouldn't be any reason why it won't start after you are done as long as you remove the air filter and drain the oil before you start, you are not going to be taking anything apart on the top of the engine. After removing the engine from the chassis, turn it upside down, remove the sump, replace the seal in the sump, make sure the gasket surfaces are clean and dry, install the new sump gasket (dry), and reinstall the sump. Torque the sump bolts to 200 in/lbs starting with the sump bolts below the cylinders. You can use loctite blue on the sump bolts but it is not required.

 

[Elkins45]

There shouldn't be any reason why it won't start after you are done as long as you remove the air filter and drain the oil before you start, you are not going to be taking anything apart on the top of the engine. After removing the engine from the chassis, turn it upside down, remove the sump, replace the seal in the sump, make sure the gasket surfaces are clean and dry, install the new sump gasket (dry), and reinstall the sump. Torque the sump bolts to 200 in/lbs starting with the sump bolts below the cylinders. You can use loctite blue on the sump bolts but it is not required.

I’ve done some reading and apparently a lot of the sump gasket failures on these motors is due to the crankcase being pressurized thru the valve galleys due to a leaky cylinder head gasket. So I bought two new head gaskets and figured I might as well do them at the same time. Which is probably just asking for trouble but it hardly makes sense to pull the engine and install a gasket only to blow it out 30 minutes after I start it.

A little Googling shows me there’s a company called Small Engine Warehouse that has a 20hp Briggs on sale for $499 right now. It struck me that my bag of gaskets cost 25% what a new engine would be. I think I’m going to spring for the new engine and then work on the old on at my convenience once the mowing season is over. Have a spare engine ready to swap isn’t the worse thing in the world. Neither would be picking up a cheap used mower with a blown engine and selling it at a profit.

 

[Elkins45]

Well, it’s supposed to freeze here soon and it hasn’t rained in weeks. I figured my mowing season is essentially over so I did the gasket swap this weekend. The worst part was scraping off the old gasket and cleaning up the pieces that fell into the crankcase. This engine has over 600 hours and I was amazed how clean it was inside. Other than the residual oil it looked like it just came out of a box of parts.

So far no leaks. I went ahead and adjusted the valves and now it even starts easier. There was enough play in one of the intake valves that apparently the compression release wasn’t engaging. It cranks a lot easier now.