brucekellett

This is the second engine that's having this problem. It looks like the oil leaks--after the engine has warmed up--at the seam between the sump and crankcase engine block. Right below the cylinder, oil filter side. First engine started this after 100hrs, this one after 70 hrs. What's going on? I change the oil, filter, air cleaner regularly. It looks like that the crankcase base is only $80, but I would need to remove the engine from the tractor. How hard is this? I've worked on old vw engines. Can I try tapping up the seam, to get me through to the winter?

K-B

It could be caused by improperly torqued sump cover bolts. (Possibly from the factory). Were both engines on the same machine?
You don't need to replace the crankcase base unless it's cracked or damaged, just buy a new gasket. You will need to remove the engine from the tractor, and this process can vary greatly in the degree of difficulty, depending on a lot of factors, from the brand of tractor to how long it's been on the machine.

brucekellett

Yea, its the same tractor, Sears DYT 4000. My guess is that the engine is bolted too tightly to the frame and the difference in thermal expansion between the engine and sump pan is causing the strain. Aluminum block/sump and steel frame also would also create strains. Maybe rubber footing between the engine and frame would help? Alternately maybe its the oil pump/strainer is clogged and somehow causing this leak. This engine also has a air filter system that doesn't close properly. But thats another problem.

For this job cracking the sump pan off the crankcase might be a difficult task too. First time, my guess this job is going to take 6hrs minimum.

Thanks for the reply

K-B

I doubt that the problem is the engine bolted too tightly. There's thousands and thousands of lawn tractors out there with the engines bolted directly to the frame. One thing that can back bolts out is excessive vibration, though.

Separating the cover from the crankcase is not usually too difficult, (I've done quite a few) Usually all it takes is some gentle persuasion with a rubber mallet, although you may have to use a puller if it is too tight. Make sure you clean up the crankshaft well with a fine emory cloth or steel wool, so the cover slides off smoothly.

brucekellett

Well the engine came off easier then expected. Also the sump engine came off fairly easy. The bolts were not on very tight at all. Is that normal? I discovered from the engine code that this is a rebuilt engine.

The sump engine is fine, but the gasket was broken. So I've ordered the engine gasket kit, as it looks like I'm going to remove the oil pump. Now putting it back together should I first remove the oil pump? The shaft pump looks like it would be difficult to line up when sliding the whole thing back together. Also I left the governor linkage plate connected as this didn't look like it was easy to remove.

K-B

Perhaps the bolts were not torqued properly when it was rebuilt. If you need the torque specs, post the model number.