Lower end seals on 300 promax

[Screaming Pete]

It seems that everone i know with a 300 has water intrusion from the uppper seals or is it just me feeling sorry for my self , second lower end 1 yr old and need s seal al ready

[TOBTEK]

THATS A BUMMER! WHAT DO I NEED TO BE LOOKING FOR?

[Screaming Pete]

Originally posted by TOBTEK
THATS A BUMMER! WHAT DO I NEED TO BE LOOKING FOR?
Take off your prop and there is a screw you take out to drain your oil in the lower end, thier is also a screw on the upper right of the lower end thke that one out and it will let the oil drain from the bottom. if thier is water in the lower it will come out first. Oil flotes on top of water. alittle is just condinsation alot is a seal leak at the prop seal or (most likely) top seals, oil comming out the vent holes is also a dead giveaway.

[OH-ZONE]

I too have had this problem. I've got an 01 300x. Seems I'm told almost every season that the prop shaft bearing has more play in it than it should and it requires replacing. Always wondered if this is a way for the shop to make some $$$. 1St year it was under Merc's warrantee so no problem. Since then its been under the extended warr. but now its eating into my total coverage $20K amount. Last season the upper seal went due to corrosion of the upper drive shaft (which had to be replaced) with about 130 hours on the motor. Seems that the shaft is hardened steel to hold up to the HP but can't hold up to the elements, even with mainly fresh water use and regular flushing when in salt. Again not a cheap repair... the shaft is expensive. Merc was nice enough to warrantee it under their corrosion warrantee. Next time which I'm sure is not far away, I'll be sporting the tab. I can hardley wait!

[randy77zt]

i change my lower unit oil about every 3 times i use the boat.if you catch the water before it really thins out the oil it will save parts.maybe have the bottem of the shaft chrome plated or heat treated or hard faced where the seal runs?

[DCB]

Call Lakeland in Havasu, they have their own aftermarket seals for the lower unit that hold up much better than the stock ones.
I had to replace mine under warranty, then it happened again, so I had Lakeland put there's on, and have been trouble free since.
Good luck

[Screaming Pete]

Thanks for your input, I think Merc should just rent us the motors for 20K and fix all these reaccuring problems on thier dime

[pussy cat]

I too have had this problem! I have a 30 ft. spectre with twin 300 pro max's. Lakeland believes most of the water is coming from the shift shaft seals. Lakeland has there own billet shift shaft housing with seals. This seemed to help me a lot. Also you should change the lower unit oil as much as possible being that there is only one quart down there! cheep insurance! See ya on the water!