Lower unit seems hot

[Bradg]

I have a 1982 70 hp Johnson Model# J70TLCNB<br /><br />The lower unit seemed to be very hot the last time<br />out. Was pulling water tubes with kids on them for<br />about 1 hour. Is this normal or do I have a start of a problem?<br /><br />Also what lower unit gear oil is need for this engine? Is synthetic oil available?

 

[roscoe]

Re: Lower unit seems hot

Check your lower unit lube for water contamination and metal shavings.<br /><br />Change the lube with "lower unit oil" made specically for marine use. It is available at any outboard dealer, and most auto parts stores, hardware stores, etc.<br /><br />Put new seals (gaskets) on the drain and vent screws when you change the lube.<br /><br />If you are low on oil or have water contanination, some of the seals have gone bad.

 

[Bradg]

Re: Lower unit seems hot

The lower unit oil was checked for contamination when boat was in the shop for spark problem just a few weeks ago. They said no water in oil.<br /><br />I will check the oil again to be sure.<br /><br />I seen some posts that have said that type "c" oil is needed. Does this engine use this oil or regular<br />marine gear oil?

 

[ledgefinder]

Re: Lower unit seems hot

Do you mean lower unit, or is it the midsection that's hot?

 

[Bradg]

Re: Lower unit seems hot

Sorry, new too boating.<br /><br />Yes it is the midsection that is getting hot.

 

[voodoo]

Re: Lower unit seems hot

that is also known as the exhaust tube.... define hot.

 

[rickdb1boat]

Re: Lower unit seems hot

Regular high viscocity lower unit lube is the right thing to use. And yes, they do make synthetic lower unit lube if you prefer that..

 

[ledgefinder]

Re: Lower unit seems hot

OK, the midsection (or exhaust housing) contains an exhaust pipe in the middle, surrounded by an outer housing that is mostly filled with water. The problem is (maybe) your midsection isn't staying filled. <br /><br />Sometimes this'll happen when the junction between the midsection and lower unit is unusually leaky. That junction usually leaks some. There is no seal or gasket on the midsection/lower unit junction, it is just two metal surfaces abuting each other. It's good practice to put a little gasket sealer on the surfaces.<br /><br />Has the lower unit been off recently? You might check to see if the bolts are loose, or whether there are any big leaks at the junction.

 

[Bradg]

Re: Lower unit seems hot

Thanks for the help.