John Deere LA125 Lawn tractor 21HP B&S single crankshaft Oil Seal needed.

[Rock Crawler]

Well. That **** show was defeated last weekend. It turns out that the fellow who sold it to me with the bad head gasket forgot to mention that he ignored the leaking gasket to the point of running it dry and destroying the crank and sump as they attempted to trade material back and forth. Now I need to turn the crank down and open the sump bearing surface up and then use a brass bushing to get back to where I need to be. And I'll end up needing to locate a seal that can bridge the gap as it ends up. Ignorant dude. I wish I knew it was run dry. View attachment 827012

 

[RandyT]

Rock Crawler. Low oil damage is very rare on the lower crankshaft bearing. should of seized and broke the rods at the crankshaft before that happened. Looks more like oil contamination or can also be caused by running a shorted electric pto clutch that causes arcing at the bearing surface.

 

[Rock Crawler]

Rock Crawler. Low oil damage is very rare on the lower crankshaft bearing. should of seized and broke the rods at the crankshaft before that happened. Looks more like oil contamination or can also be caused by running a shorted electric pto clutch that causes arcing at the bearing surface.

This is a super el-cheap-o JD LA series with a cable operated drive belt tensioner. It is a cable to a coil spring that you rotate a lever on the dash to pull the cable tight and apply the spring pressure to the once limp deck belt. So no electric PTO on the crank, just a solid fixed pully with a limp belt until you pull manual tension on the lever.

I guess it could have been abused oil service intervals or even no oil service, the previous owner admitted to not being mechanical at all. The cylinder bore looks really good with plainly visible cross hatching. I started removing parts to further pull the engine apart, this evening I will pull the upper flywheel and hope to get the crank in hand. Then to my buddy for some machining work.

I am getting sidelined a bit from this project by a 2010 Exmark Laser HD ZT that was given to me with a hydraulic issue. I will be bouncing back and forth on these as time permits. Mowing season is about ever, so I have months to play around.

 

[Rock Crawler]

I thought I would update what I did, since I kind of forgot about this. My buddy has a lathe, so he turned the lower sump case that I showed in the pics above, then he turned down a bronze sleeve and cemented it in with the oil feed hole still in play. He turned the crank down 0.005", so the bronze sleeve was adjusted for that, and the OEM seal was able to work perfectly with the slight undersized crank snout. I hauled that little green tractor to our camp and it has around 8 or 9 hours on it since, and it is leak free and running perfectly. I gave my buddy $50 for his help, and maybe spent $40 on gaskets and seals. So for under $100 dollars I did get the little single cylinder back running and happy. Now I'll keep it filled with clean high zinc air cooled engine oil and see how far she can go.