'86 L115 Lower Unit gear lube leak

[deerhuntre]

Uh oh...Trolled on Lake MI for a few hours last evening and everything seemed to run just fine. This evening I noticed a small puddle and lube running down the skeg (pardon the dings....it came that way). Does this mean I'm going to need to replace an oil seal at the prop-shaft? What else should I be looking at?

Please view the photo's:

http://www.thedubins.com/boat/IMG_7418.JPG

http://www.thedubins.com/boat/IMG_7419.JPG

http://www.thedubins.com/boat/IMG_7420.JPG

Thank you!!

 

[Bob_VT]

Re: '86 L115 Lower Unit gear lube leak

Yes, the seal is shot... is there any wobble in the prop? Hopefully the seal is just gone and the prop shaft is running true.

 

[deerhuntre]

Re: '86 L115 Lower Unit gear lube leak

No wobble at all. The prop is completely tight. So what is the repair like? How much has to come apart? I'm going to get my manual from the garage....

 

[deerhuntre]

Re: '86 L115 Lower Unit gear lube leak

...OK...I read the manual and it really doesn't look so hard at all. I may even have a suitable puller in my toolbox. Is there anything in particular I should look for when I have the thing apart?

Anyone have any suggestions for the 'cover nut', or must I find the special tool to remove and reinstall it?

Thank you!!

 

[diaric]

Re: '86 L115 Lower Unit gear lube leak

you have a 50/50 chance its the waterpump base.they leak more often. mine would leak out after i tipped the motor up for transport then dropped it when i got home. if i put the vent screw in after filling and gave it another pump or two, i would hear it leak in the top of the leg, not the bottom. and the lube would appear out the exhaust of the prop hours later, not right away.

 

[deerhuntre]

Re: '86 L115 Lower Unit gear lube leak

I didn't think of that. I recently rebuilt the water pump. I'll try your 'pressure' test with the vent plug in. Thanks for the suggestion.

 

[deerhuntre]

Re: '86 L115 Lower Unit gear lube leak

diaric, you have me thinking, which is dangerous!! I pulled off the prop et al and examined the seal. There is no evidence of any leakage at the prop shaft seal. However, the remaining water (the motor is trimmed up a bit for trailering--and supported) in the lower unit is mixed with the same oil thats in the photo's. Now I really am thinking you may be onto something regarding the water pump.

Wouldn't I see signs of leakage if the prop shaft seal was bad?


Thanks again!!

 

[diaric]

Re: '86 L115 Lower Unit gear lube leak

the prop shaft should give you a fairly steedy drip, till the level comes down. the waterpump should just leak out what came out while it was trimmed up then kinda stop till next time. if i dropped mine after a run on the lake, it dripped for a few hours then nothing. if i checked oil level, it was almost full of milky oil

 

[deerhuntre]

Re: '86 L115 Lower Unit gear lube leak

Cool! I had trimmed the motor way up because of launch conditions, so maybe the water pump leak is what is going on. I'll keep an eye on it and investigate further and fix it when I get a chance.

Thank you!

 

[Chris1956]

Re: '86 L115 Lower Unit gear lube leak

Deer, Are you sure it is gear lube? Gear Lube stinks, while 2 cycle oil does not. Those prop seals are pretty tough, but they do fail. If in doubt, fix the waterpump seals and gaskets first.

 

[diaric]

Re: '86 L115 Lower Unit gear lube leak

his pics look like contaminated gear lube. exhaust oil looks blacker

 

[deerhuntre]

Re: '86 L115 Lower Unit gear lube leak

I checked...it does smell like gear lube. And nothing further has leaked since yesterday.

 

[diaric]

Re: '86 L115 Lower Unit gear lube leak

most likely water pump. get a rebuild kit. the bases are sold seperatly, but they usually ok, unless cracked. the seals and o ring under it will need changing. and makesure no corrosion on driveshaft where it all rides. you should be ok, newer motors had stainless driveshafts or higher quality steel that didn't rust

 

[deerhuntre]

Re: '86 L115 Lower Unit gear lube leak

Is there any trick to getting the water pump base off the lower unit?

 

[Chris1956]

Re: '86 L115 Lower Unit gear lube leak

Deer, Usually you will need two large flat screwdrivers or tire irons to pry up the waterpump base. Pad the "fulcrum" area so you do not scratch up that area.

 

[diaric]

Re: '86 L115 Lower Unit gear lube leak

if it looks like there's corrosion around the studs, soak with some penetraring oil. they usually get plugged up with water minerals and metal oxides from steel contacting alluminium

 

[deerhuntre]

Re: '86 L115 Lower Unit gear lube leak

Awesome, thanks!! See, I did service the water pump this year but I didn't do anything to the pump base because I was afraid I'd cause damage when removing it. So I only replaced the impeller and related items in the pump cover. So now that I know how to get the lower unit on and off....good thing I had that practice! I guess I'll re-do the work again soon, but this time will do the complete job. By the way, I did find it quite a pain to align the copper tube correctly while also trying to line up the gear splines when inserting the lower unit. But I think I've go the hang of it, now.

Thanks for the advice.

 

[diaric]

Re: '86 L115 Lower Unit gear lube leak

a third hand comes in handy for that to help hold and align. i usually slip the prop back on and rotate slightly till drive shaft lines up(if done in gear). if you do break the base or find it cracked, i think this is your base. don't have your serial, so just a guess. http://www.iboats.com/mall/partfind...gd_poid=110982&gd_row=29&**********=537393921

 

[deerhuntre]

Re: '86 L115 Lower Unit gear lube leak

I've been looking in the service manual and I'm a bit confused about the 'shim' part of the reassembly. Could someone please explain how you 'shim' the waterpump base when installing it?

 

[Chris1956]

Re: '86 L115 Lower Unit gear lube leak

Deer, There maybe shims under the waterpump base. You should identify them and reinstall them with the new base.