lower unit oil change

[schmitty66]

Last weekend i put my '92 ChrisCraft, 3.0L OMC to bed for a long Canadian winter. While changing the l/u gear oil i thought of another 3 questions. So i took the dipstick out and opened the very bottom screw to drain the oil. Then i filled it through the next screw that is about 8inches above the first.
1-what are the 2 screws on the same side but near the top of the unit used for?
2-Why can't we just pour the oil in through the dipstick hole?
3-I noticed a tube right beside the engine dipstick that has what's looks like a brass 'male' garden hose adapter. Is this to pump out the engine oil?

thanks guys...

 

[NelsonQ]

Re: lower unit oil change

Removed content... Incorrect and misleading info... Sorry

 

[jerryjerry05]

Re: lower unit oil change

Nelson stick to outboards.The two screw on the side on the top are casting plugs and DON"T remove EVER!!!!
If it's a Cobra drive they MUST be filled from the right side above the drain plug if filled from the bottom or top you won't get oil in certain places and the first time you start it,it will be low on oil and you will ruin the gears in the top.
The dipstick hole is just that a dip stick hole.Don't use for anything else.
The brass fitting is an adaptor to hook up oil pumpers.
You sure you winterized this correct??
You loosen the drive to let excess water drain? How about drain plugs on the block??? Just wondering.Next ??? You have a manual??? If you buy a factory manual it covers this. SEloc and Clymer manuals suck.Jerry

 

[sea wolf]

Re: lower unit oil change

Last weekend i put my '92 ChrisCraft, 3.0L OMC to bed for a long Canadian winter. While changing the l/u gear oil i thought of another 3 questions. So i took the dipstick out and opened the very bottom screw to drain the oil. Then i filled it through the next screw that is about 8inches above the first.
1-what are the 2 screws on the same side but near the top of the unit used for?
2-Why can't we just pour the oil in through the dipstick hole?
3-I noticed a tube right beside the engine dipstick that has what's looks like a brass 'male' garden hose adapter. Is this to pump out the engine oil?

thanks guys...

The tube you are referring to is used to hook up a suction pump to remove the old engine oil when you change it. On a Cobra you do not fill the drive from the bottom hole as the other poster told you to do. You fill from the middle hole with a hand pump. If you fill from the bottom you're drive won't last for 10 minutes before dynamiting as the upper half won't have any oil in it. You can't fill the drive from the dipstick hole because the bottom half will run dry. By the way, did you remove the plug on the l/u port side to drain the pickup pump in the lower unit? If you didn't, the water in there will freeze. There are only 2 plugs on the starboard side of that drive that you have to deal with. The bottom plug is to drain it, the middle one is for filling the drive. Your drive will take 60 oz. to fill. Don't overfill it.

 

[schmitty66]

Re: lower unit oil change

hey guys.....i did drain the l/u on the port side using the plug that is quite high on the unit...not alot of water came out though...even after i tilted it up all the way. oh yeah.....none of the plugs had o'rings that i could see....are they black rubber? ....and the oil wasn't contaminated with water.

so...because i'm a asker of questions....the top hose on t-stat on the left side facing the back of the boat.....that leads down to a silver cannister then hoses go off from there....can you explain their function...cooling?

hey jerry...which manual do you suggest?

 

[jerryjerry05]

Re: lower unit oil change

Show a pic of the hose thingie you want identified. The factory manual is the only way to go.Try your local dealer.It's expensive but well worth it.
Jerry