Gear Shift Lube

[Simon Wootton]

I have recently bought a boat with a 4.3LX Mercruiser Alpha 1 unit (1996). Having previously had outboards I have no experience of which oils / lubricants are best used.<br />On top of the engine is a small reservoir that appears to be the supply for the gear shift(?). This is tricky to access on my boat and even trickier to see if there is a reference to what oil should be used! I can see the oil is below the "fill to" level.<br /><br />Which oil should I use and am I right in saying this is the gear shift lube reservoir?<br /><br />Can anyone help please. <br /><br />Thanks!

 

[DJ]

Re: Gear Shift Lube

Simon,<br /><br />I would bet that reservoir is for power steering fluid.

 

[Simon Wootton]

Re: Gear Shift Lube

Thanks - I should have said that my steering reservoir is right on the front of the engine, this has a small dipstick in it to check the level - Simon

 

[DJ]

Re: Gear Shift Lube

Simon,<br /><br />Second guess is a remote reservoir for the lower unit lube.<br /><br />Unless, this set up has hydraulic (not cable) gear and throttle controls??

 

[Simon Wootton]

Re: Gear Shift Lube

I reckon that it is the reservoir for the lower unit. If it is do I use the same sort of lubricant as in the gearbox of an outboard?

 

[DestinyEscape]

Re: Gear Shift Lube

Simon,<br /><br />Congratulations on the new boat. From what it sounds like I have an identical setup in a boat that I bought at the end of last season. I have just gone through getting it ready for this year and had all of the same questions you do.<br /><br />First, I would highly reccommend the Clymer Shop Manual for that motor ($24.95 at Boater's World). If the reservoir you are speaking of is on the starboard side of the motor, at the top in the front, then it is the reservoir for your drive oil (lower unit). I used what the shop manual reccommended: Quiksilver High Performance Gear Lube (Quiksilver is Merc's factory brand). I would reccommend changing the oil in the drive unit if you are not sure when it was last done. My book reccommends once per season or every hundred hours.<br /><br />To change it, you have to loosen a screw on the stern drive unit labeled "vent" near the top of the unit on the port side. The screw on mine was very visible because it is stainless steel on a black unit. After loosening this screw to allow air into the unit, loosen the drain screw. You should find this on the very bottom at the front of the prop shaft housing. This is the torpedo shaped piece that the prop comes out of. You may have to lay down under the unit or feel for it with your fingers. I overlooked it several times while searching. Set an oil container underneath the unit and remove the screw. It will take a good while for the lube to drain, as it is very thick. After it drains, use a hand pump to empty the reservoir you mentioned that is attached to the engine. To add fresh lube back into the unit, you must purchase an inexpensive lower unit lube pump ($9.95 at Boater's World) and screw it into the drain screw hole. Pump the lube into the unit until it spurts from the vent hole. It should take 1.5 to 2 containers of oil. After completing all of this, don't forget to add lube back into the emergency reservoir. <br /><br />Just as a sidenote, should this reservoir need constant refilling you may have a problem with the drive unit. It should not be burning up or leaking the oil. This reservoir will only feed the unit when it is low. However, you may have to add to the reservoir after you run the machine for the first time.<br /><br />Hope this helps.<br /><br />CP

 

[Simon Wootton]

Re: Gear Shift Lube

Thanks for your detailed answer CP. It sounds straight forward enough now.<br /><br />Simon

 

[Doug Durako]

Re: Gear Shift Lube

Simon---if you run your boat as hard as we do, I would change the drive oil every 40 hours or so. I start with new oil at the beginning of our season and usually change before July 4 (heavy boating weekend here). Many people pop the plug at the end of the season to make sure there is not water in the drive unit----it will drain out first and you will know immediately.<br /><br />Can't have much water in there or it will crack something if stored where it freezes.<br /><br />That gives you the chance to look at the oil, check for any signs of water and/or noticeable metal shavings.<br /><br />Caution: fill the unit slowly and do NOT overfill. Read the manual carefully until you get the hang of it.