Sportmaster on 2004 Mercury 225X ProMax - too much oil?

**bb21xd** · 03-01-2014, 08:06 PM

I change the oil in my Sportmaster lower unit by draining it out, pump it in the lower hole until it comes out the vent (upper hole) then put the plugs in with new gaskets.
If I run the engine fast there is some lube that leaks out of the relief hole in the side of the lower unit. Evidently this oil is being pushed out of the shift shaft seal. So, thinking there maybe an issue with the shift shaft seal I replace it. Now, after fishing last Saturday there is a puddle of gear oil on the floor and it is coming from the prop shaft seal, it is pushed out. Am I over filling the gear case? If so, how?

Engine has 120 hours on it, never any prop damage.

**dagodiver** · 03-01-2014, 08:13 PM

I just had the same issue. I replaced the waterpump base
and the shift shaft seal all good now.
My bearing was walking the seals out om my carrier so I turned
a groove and installed a snap ring. Green lock tight on the bearing
also.
Your sportmaster should have the clip already.
Dago

**bb21xd** · 03-01-2014, 08:16 PM

I put a new water pump base in about 6-8 engine hours ago because I figured water was getting in the gear case. I've checked all the oil drained out each time, never any water.

**Euroski** · 03-01-2014, 10:30 PM

Level the drive and leave to top plug out overnight until the extra drips out? Had the same problem on my 280 when I first time changed the oil.

**TEXAS20225** · 03-01-2014, 11:03 PM

case MUST BE LEVEL

**bb21xd** · 03-02-2014, 06:10 AM

I use a level on the cavitation plate and she's dead nuts level. Should I trim it so the vent is slightly lower so the oil level would be lower?

In the mean time, I've got to find someone in the North Georgia, SE Tenn area to stick new prop shaft seals in it this week. Recommendations?

**pkstv** · 03-02-2014, 10:34 AM

Oil expands when hot and will blow seals . Fill to top then take your time putting in drain plugs most mod vp racers ran units a little low to allow expansion of oil about 1/3 cup low

**bb21xd** · 03-02-2014, 11:42 AM

Good idea! The Mercury service manual says 22.5 oz so 1/3 cup would be right at 20 oz.

THANKS!

**njj502** · 03-02-2014, 06:22 PM

I had the same problem. When I fill it now I'm sure it's level and fill till it comes out the vent. Remove fill tube, put in bottom plug & then put the vent plug in. This allows a little bit to leak out giving you some expansion room.

**vnemous** · 03-02-2014, 07:15 PM

Nothing to do with your problem, I think, but the blue fiber washer do a much better job of sealing than the yellow washers JMO

**Onetime** · 03-02-2014, 08:10 PM

After filling put the top plug in and leave the bottom one out. Let about a shot glass drain out the bottom plug. Might have to crack the top one to let it drain, which is a good sign your gearcase is sealed well.
You want to have a couple of ounces drain out so when the oil expands it has some place to go. Air compresses oil doesn't.

**ActivatedSludge** · 03-03-2014, 06:36 AM

Originally Posted by Onetime

After filling put the top plug in and leave the bottom one out. Let about a shot glass drain out the bottom plug. Might have to crack the top one to let it drain, which is a good sign your gearcase is sealed well.
You want to have a couple of ounces drain out so when the oil expands it has some place to go. Air compresses oil doesn't.

That's how I do mine.