Oil Pan Failure

[Ron Hill]

Figured it was time to post this topic again.  Here are some of the most common causes of having to replace the oil pan on a marine engine:

1.  Leak from the salt water pump (especially in salt water)!!  The seal that holds the water in the raw water cooling pump starts to fail and leaks water.  The water comes out thru the weep hole and runs down the front of the engine and onto the oil pan/engine mount.  Over time the pan flakes off it's paint and rusts thru from the outside.
2.  Short runs of the engine when it doesn't get up to operating temperature.  Water condenses on the inside of the oil pan.  Water being heavier than oil goes to the bottom of the oil pan and rust it out from the inside.  

Biggest cause of an oil pan gasket leak -- An owner tightening (over torquing) just a few of the bolts - and breaking the oil pan seal.  Usually in the front, thinking an oil leak from the raw water pump is an oil pan leak.  

[SeaFever]

Ron,

What is the tightening torque for the oil pan bolts? I just cannot find that information in any of the manuals I have including the Kubota wokshop manual.

I am hoping you have the information.

Thanks,

Mahendra

[Stu Jackson]

Is it buried somewhere in Dave Sanner's great writeup?  http://www.c34.org/wiki/index.php?title=Rebuilding_the_M25-XP

[Ron Hill]

Mahendra : The reason that you couldn't find the torque specs for the oil pan bolts is because they are not a bolt that has a special torque value!  This means that the torque is by the size of the bolt and it's grade.
I'll guess (don't remember for sure) that the oil pan bolt is an M8 size and grade #4.  Those bolts should be torqued to between 13.0 and 15.2 ft-lb .  The most important thing about the tightening of the oil pan bolts (and other multiple bolts ie. head bolts) is not the exact torque, but that they are all tightened to the same torque.  Also make sure that you tighten them in a diagonal manner.

I recommend that you talk to your local Kubota dealer and ask them the torque for the oil pan bolts on a D950 engine/ B7200 tractor (M25XPA engine).  I found it best to go in to the dealer and talk to one of the mechanics, rather than a telephone call - you'll learn much more!  

A thought.  Hope this helps.  

[Ron Hill]

Mahendra: I just re looked at your post and saw that you have hull# 17__ something.  If that's is correct you must have a M35XPB engine.

I just looked up and find that your oil pan bolts are an M6 capscrew so that torque would be
5.8 to 6.9 ft-lb.  Disregard the D950 and B7200 tractor as your's is a differant model, but I'll guess that the oil pan data is still the same. 
If in doubt, visit the Kobuta dealer and talk to one of their mechanics.

Anytime you ask a question, please list your Hull # and in your question the engine that you have!! 
Hope this helps.

[SeaFever]

Thanks Ron and Stu.

It definitely helps. I will have to use the torque based on the size of the bolt. The manual does provide that information of all of the non-specialized bolts.

BTW, the reason, I did not mention my hull number etc is that I have a Pearson 10M Hull #43. My 10M currently has a A4, however, I have acquired a M25 (Kubota D850) and am tinkering with it in my garage. I have learned a lot with the few projects/upgrades I have done on it so far. The information on this forum is really great  Thanks to you all!

I might just replace the oil pan gasket before I put it in. Just for peace of mind. I will have to do the suggested harness upgrade. I am not yet decided on 'moving the oil drain to the back of the pan'. I also am planning to make a mold of the engine bottom to help me make the changes to the stringers and the installation easy. Wish me luck with that. I am still figuring out the best/easiest/cheapest way to make the mold. Wish me luck...

Cheers,

Mahendra