Yanmar 2gm Oil Leak Troubleshoot . . .

[Aotearoa]

My new 2gm with less than 100 hours has a small leak which seems to be coming from the bell housing gasket (where the gearbox connects to the block).

This is a seemingly minor leak, but it concerns me! as i am thinking the main bearing seal is leaking at the back of the motor, and that being the case it may be a huge job to replace it, and furthermore i will be the one doing the replacing!

Has anyone had this experience with a 2gm motor? Perhaps its not as bigger job as i think to get a new seal in there?? Any light that you may be able to shine on the subject would be much appreciated for my peace of mind....

thanks

Ross

[tropicalescape]

I have the same engine in a 32 ft . and its not a big deal to remove if one has basic skills and a block and takle and /or some one to help..never replaced a seal but should not be to much trouble.Do you have a manual?pm me if you need help ,maybe i can help ya .Good luck DVC

[jaredko]

I recently replaced my rear driveshaft seal on my 2gm as I suspected it was the source of a similar leak, turns out it wasn't from there. I still haven't stopped it, but I think it may be the valve cover gasket (should have started with the easy stuff!)

If you do replace the seal I'd be happy to answer any questions.

[mfeene01]

I also had such a leak on my 2gm20f. When I asked a Yanmar mechanic he said that there was an oil pipe that runs to the back of the motor which could be the problem. Otherwise it was probably the rear main seal.

Mine turned out to be the rear main seal. A friend of mine has the same leak with his 20gm20f.

Good luck


Mike....

[Chief Engineer]

Double check your oil level also

[toppozinim]

Originally Posted by jaredko

I recently replaced my rear driveshaft seal on my 2gm as I suspected it was the source of a similar leak, turns out it wasn't from there. I still haven't stopped it, but I think it may be the valve cover gasket (should have started with the easy stuff!)

If you do replace the seal I'd be happy to answer any questions.

Hi, I know this is liked to an old post but I have the same issue with my 2gm20f. My leak appears to be coming from the rear seal....do you have the steps involved in replacing the seal???
Thanks

[sailorchic34]

To replace the main seal on a Yanmar GM series engine.

Disconnect the transmission from the engine (you'll need about three inches of space to slide it back and lift it aside. You'll need to disconnect the prop shaft and slide it back too.

You'll need to brace the rear of the engine or support it from the block and tacke, before removing the transmission.

Remove the damper plate and the the HEAVY flywheel. You'll either need to remove the starter and have a helper use a big flat blade screwdriver to keep the flywheel from moving while you break the bolts loose. They are torqued to 60-70 foot pounds. Alternately if you have a 36mm socket your helper can hold the nut on the crank pulley while you break free the bolts. The crank pulley nut is torqued to a higher value (75 foot pounds I think).

Then just pry the old seal out and install the new seal.

Then just put it all back together. Probably will need to check prop alignment too. Easy pezy.

[Badsanta]

Sc you make this sound so easy. I am really impressed. You need to write a book.

[sailorchic34]

Compared to pulling an engine and rebuilding it on deck, replacing an engine seal is a piece of cake. Gee hardly more then a two day job.

I know, I know I've gotten jaded about what a big job is.

[Sailorman Ed]

My oil leak seems to be coming from the rear main seal (with SD20 saildrive).
So Sailorchick says it is easy but does anyone know the common seal number or do I have to get this from Yanmar?