MM G1000 Vista Oil Pan Leak

Jeremy L

Member
Recently we did some work on our 1967 MM G1000 Vista (Diesel) which required us to remove the oil pan. We changed the oil pan gasket before putting the oil pan back in place. Since doing this work, we fired the tractor up and noticed oil fairly steadily running out of the inspection plate at the bottom of the bell housing and around where the oil pan bolts to the bell housing. When we changed the gasket and were cleaning the old gasket off of the bottom of the engine I did notice that the rear engine seal retainer sat slightly higher up than the bottom of the engine casting where the oil pan mounts to (very little but it was a bit higher up and when scraping the old gasket there was a distinct lip/edge at the joint between the bottom of the retainer and the bottom of the crankcase. I have not removed the oil pan again yet but I believe the oil leak is coming from this area. Has anyone had this issue before and if so how did you fix the leak (gasket glue both sides of the new oil pan gasket OR make a thin piece of gasket to go in the recession at the bottom of the retainer, etc.)?

Thanks in advance for your assistance.
 
You changed the pan gasket but did you replace the rear oil seals around the crankshaft? If not, they can leak a lot of oil out into the bell housing where it will drip or even drizzle out when it gets warmed up and working. They will leak so bad that the clutch will slip to the point that you can't pull any load at all. It's a job to get the top one around the crank but it can be done with the right tool and by loosening the main caps some. You also will need to replace the small square pieces that slide into the channels that hold the lower half of the seal in place. When you fit the seal into the lower half just cut it a bit long and it will squash tightly against the upper half to make a good tight fit. If you do it right it will not leak at all.
 
The rear seal retainer is shimmed, and it should stick below the oil pan, I think .005. Also I don't believe that the gasket for the pan can allow oil into the bell housing.

I usually replace the cork sticks and the bottom half of the seal when I pull a pan, but I will never even again attempt to replace an upper seal without removing the crankshaft. For the time usually invested in replacing that top half of the seal I could have pulled the engine, removed the crankshaft put a seal and bearings into it and put it back together.
 
Your right, putting in that top seal is difficult to say the least but i have done two vista's and others too using a wire tool on one and them making my own out of some other wire. The hard part is getting them started without fraying the end, once they start you can roll the crank while pulling and they will come around with a little luck. Then I made a sharp tool to chop off the excess flush with the casting, it will sheer it off cleanly.
 


I got a kit years ago that had a Chinese finger puller as part of it. That seemed to work good while rolling the crank over. I don't remember what motor I bought it for.
 
I should add that this tractor was not leaking prior to taking the oil pan off so I believe the leak is related to the oil pan gasket for that reason.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top