Automatic transmission "Stop Leak" in lower unit

[pecheux]

good day, My 15 hp Force OB's lower unit does take in approx 1 soup spoon full of water per season. I have decided to change the LU oil twice per season since a pressure test did not show any leak. In the meantime the OB is in storage for the winter months and as preventive maintenance I have added a mixture (50/50) or LU oil with automotive 'transmission stop leak" additive hoping the seal may swollen a bit during the winter season, then I plan to change the LU oil again in the spring prior to using the motor. Question is: was that a good idea ? Or should I dump the mixture and replace with 100% LU oil right now ?

Thank you.

 

[gustafsonerik]

Re: Automatic transmission "Stop Leak" in lower unit

i used lucas power steering stop leak and it actually work very well that was two seasons ago..my friend had a 1971 mercury 650 that water was getting into the cylinders because of a bad gasket..he used one of those head gasket repairs in a bottle steal seal,perma seal etc and it worked..he filled a trash can with water so the water would recylle itself and get hot enough to work..so i would try it if i was use but use lucas there the best

 

[pecheux]

Re: Automatic transmission "Stop Leak" in lower unit

gustafsonerik: tx for your feedback. I actualy used automatic transmission stop leak additive, but I can understand power stearing stop leak would perform the same.

Did you use the product 100% pure or did you mix it with LU oil ? Also did you run the OB with that product in the LU ?

In my case the 50/50 LU oil/stop leak was pumped in the LU for the coming winter storage months, with the intention of dumping it in the spring and replacing the oil with 100% pure LU type oil.

Let me know what you did, Tx

 

[steelespike]

Re: Automatic transmission "Stop Leak" in lower unit

That transmission treatment reminded me of of many years ago early 60s
I worked for an excellent though not too honest mechanic.(pumped gas ,oil changes etc.The 50s Oldsmobiles were sensitve to poor oil maintenance valves would clatter terribly.He would add transmission treatment and let them idle for a half hour or so.It was amazing,perfectly quiet, change oil and filter and charge for a valve job.I soon found a better job and he kept moving.

 

[pecheux]

Re: Automatic transmission "Stop Leak" in lower unit

Back in the 50's my father operated a car repair shop in a small northern town. Yes valves was a problem with most cars back then. My father used a product additive from al called Valves & Lifters. He would pour half the can in the carburator opening at high trottle creating a cloud of smoke ... then changed oil and added the other half to the crankcase and would let the car idle for 10 minutes or so .. did miracles ... but he charged the customer for the product and his time only ... LOL

 

[gustafsonerik]

Re: Automatic transmission "Stop Leak" in lower unit

use straight lucas for a bad lower unit seal..if you have a bad gasket..this is going back a few years but he used a trash can filled it with minumum water..enough to run the motor without over heating it and directed the telltale back to the can...anyway he used that block sealer i think its made by crs or prestone

 

[bchoate]

Re: Automatic transmission "Stop Leak" in lower unit

Since it is "WINTER" You might just have the time to pull the lower unit apart and inspect it for any water damage and replace ALL of the seals and may as well do water pump too while its off. Its alot easier to get a towtruck on the road but try that in the middle of the lake. Get a good manual.
"DO IT RIGHT THE FIRST TIME"

 

[gustafsonerik]

Re: Automatic transmission "Stop Leak" in lower unit

talking to someone more about this subject, i learned alot more... that i thought i'd share with you...theres a guy,i work with who is close to 88 years old so hes seen alot of outboard/mechanical works in his life..he's retired auto mechanic..he told me back in the 40's a guy brought in a 38 johnson 18hp that was leaking around one of the inside seals..ran sloppy but you could see alot of white smoke coming out of the exhaust and it would skip a few beats.since they lived on a farm he hadn't alot of ways to get new gaskets..His father(the 80yr old guys dad) told him to get a 12 eggs and get the yoke out of the eggs and put the rest of the eggs(the clear part) in a can and start the motor in the trash can..it sealed the leak totally.I asked him about this story a few times and he swears it worked..now i'm not saying do this to your motor,but its easy to say hes full of **** but thinking about it more..when a egg cooks you do get that black part around the edges which is hard..and i could see where something like that could hold..now how long it lasted or was it really good i couldn't tell you but i thought it was interesting and wanted to share it with you..

 

[freddyray21]

Re: Automatic transmission "Stop Leak" in lower unit

many of these fixes will work . . . temporarily. The stop leak products work on the rubber in the seals swelling them and make them seal. For awhile. There is no substitute for putting in a new seal kit and doing it right.

 

[pecheux]

Re: Automatic transmission "Stop Leak" in lower unit

Since it is "WINTER" You might just have the time to pull the lower unit apart and inspect it for any water damage and replace ALL of the seals and may as well do water pump too while its off. Its alot easier to get a towtruck on the road but try that in the middle of the lake. Get a good manual.
"DO IT RIGHT THE FIRST TIME"

I had the LU pressure checked and mecanic told me it was perfect, so I hate to fix something that aint broken or fix the wrong problem. Nevertheless I still get a spoonfull of water in the LU at every oil change. Been told by same mecanic (I trust him & he is reputable) that this was an unsolved issue with many Force OB's. He even refused to change the seals on my OB by saying the problem will probably still be there with new seals.