10w40 in Outdrive

bhammer · May 12, 2010

So, I just got back about an hour ago helping a friend look at a 2004 21'CC with a Merc 5.0 and gen II drive that he wants to buy. The current owner kept amazing records for all the service and parts, most of it, he did himself. The only thing he had done by a shop was to replace the bellows.

Now, the only thing I found odd while looking through the records / receipts was that there was never any Merc Drive lube purchased, only penzoil 10w40 oil. I asked the owner about it and he said he uses it in the outdrive as well.

From someone who did great maintenance, even lubed all the fittings every year, I found this very strange.

Your thoughts on this? Should he pass on the boat based on this?

bhammer · May 12, 2010

Re: 10w40 in Outdrive

Oh, and unless I hear from you guys that it is a bad idea to proceed, we are set for a trial run this evening if weather holds.

HT32BSX115 · May 12, 2010

Re: 10w40 in Outdrive

I would pass!!

Now having said that, I would also drain a little oil from the drive and see if the oil has EVER been changed.

If it has been changed and some moron did put 10w40 in it (you would be able to tell.....it would run out like water!!)

I would then offer him your best price MINUS the cost of a NEW SEI drive!! And I would tell him that!!

Jeeze!!!!!

Rick

bomar76 · May 12, 2010

Re: 10w40 in Outdrive

Would you buy a car from a guy that told you he was using 10x40 motor oil in the differential for the last 6 years?

I hope not.

HT32BSX115 · May 12, 2010

Re: 10w40 in Outdrive

bomar76 said:
Would you buy a car from a guy that told you he was using 10x40 motor oil in the differential for the last 6 years?

I hope not.

craze1cars · May 12, 2010

Re: 10w40 in Outdrive

There are a good number of older drives, and outboard drives, that have spec'd 10W-30 or 10W-40 as recommended for lower unit oil.

Granted, not an Mercruiser Alpha 1....

BUT some old Volvos, Suzukis, and others recommend it. Here's a list of Volvo drives that recommend "same as engine oil" for outdrive lube:
http://www.marinepartsexpress.com/outdrives.shtml

I say if it's quiet and working well...this history wouldn't be the one thing that scares me away. I guess I'd rather have a 6 year old drive that has been changed annually with 10w-40 than one that has the factory fill and has never been changed...like many out there.

But I've been told by many people on this forum that I'm not normal...which is entirely true. To which I say there are an awful lot of "oil alarmists" on this site...

RL Gman · May 12, 2010

Re: 10w40 in Outdrive

HT32BSX115 said:
I would then offer him your best price MINUS the cost of a NEW SEI drive!! And I would tell him that!!

I like that idea...sounds like the rest of the maintainance was done correctly (if you did a thorough check!) so yeah, offer him minus the drive cost...If it works, you still get a good boat and get to put on a new SEI (which I would love to do myself).

bomar76 · May 12, 2010

Re: 10w40 in Outdrive

Wonder if he was using Vasoline as grease......

HT32BSX115 · May 12, 2010

Re: 10w40 in Outdrive

I guess I'd rather have a 6 year old drive that has been changed annually with 10w-40 than one that has the factory fill and has never been changed...like many out there.

With all due respect, You are entitled to your opinion of course......

(Except for certain Volvo Penta drives whch DID use automotive oil, )
I would NOT touch a Mercruiser drive that had automotive oil used in it in place (recommended) standard GL-x gear oil.

guyaverage · May 12, 2010

Re: 10w40 in Outdrive

craze1cars said:
I guess I'd rather have a 6 year old drive that has been changed annually with 10w-40 than one that has the factory fill and has never been changed.......

Hell, I wouldnt.

10w40 and a typical 80-90w gear oil are actually very similar in thickness (contrary to what the numbers suggest), but the difference between engine oil and gear oil is the additive pack. Motor oils contain antiwear additives and cleaners, while gear oils contain more extreme pressure and corrosion additives, and the ingredients that perform these tasks arent the same. This drive may very well be ok, on the other hand it might be garbage and need new bearings, races, and gears.

At a minimum I would tear this drive down and inspect it (or pay a pro to do it and let them know why), check backlash, gear face wear, etc. By the time you do that you could be halfway to the price of a new drive.

HT32BSX115 · May 12, 2010

Re: 10w40 in Outdrive

At a minimum I would tear this drive down and inspect it (or pay a pro to do it and let them know why), check backlash, gear face wear, etc. By the time you do that you could be halfway to the price of a new drive

Or, ALL the way PAST the price of a NEW SEI!!

bhammer · May 12, 2010

Re: 10w40 in Outdrive

Okay, I spoke with the Buyer and he has negotiated a price based on the boat. He will now discuss with the Seller to see if he will reduce the price by the cost of a new SEI drive. If not, he plans to walk from the deal.

I have not dropped any fluids yet as we will after we do lake trials. It is 10w40 in the lube monitor. Compressions are good, plugs were changed before last season and look good.

JaseBosto · May 12, 2010

Re: 10w40 in Outdrive

If it were me, I would negotiate the price down to $1600 less than asking price for the new SEI drive. Then I would change the fluids out and use it as is till the drive blew up. The worst is you might need a tow in and then replace the leg.

Who knows, you may get 10 years out of that drive. The only thing that would worry me, is if your going out into the ocean with it. Then again, I would have a kicker onboard if you were doing that anyways.

QC · May 12, 2010

Re: 10w40 in Outdrive

You wanna know what I think? We should all pitch in and buy this boat. We'll use it to test all of these stupid oils and additives and mouse milk and synthetic and vegetable oil. And when all of it works without a failure we can pretty much hang up all of these oil threads for good . . . That's what I think.

HT32BSX115 · May 12, 2010

Re: 10w40 in Outdrive

QC said:
You wanna know what I think? We should all pitch in and buy this boat. We'll use it to test all of these stupid oils and additives and mouse milk and synthetic and vegetable oil. And when all of it works without a failure we can pretty much hang up all of these oil threads for good . . . That's what I think.

Well,

Ordinarily, I would agree with you except where it comes to hypoid gear oil vs motor oil.....

I don't think there's a lot of argument with point made below.........

Motor oils contain antiwear additives and cleaners, while gear oils contain more extreme pressure and corrosion additives, and the ingredients that perform these tasks aren't the same.

Some truck transmissions made by ZF that is installed in many of our trucks actually use automatic transmission oil! But they're designed to use it.

If you told a Mercury engineer that you used motor oil in one their drives, I'll bet the reaction would be interesting to say the least.....

Here's a great short bit of reading on Gear lubricants. it's fairly clear to me that certain gear designs can use different lubricants.

http://www.api.org/certifications/engineoil/pubs/upload/1560.pdf

Cheers,

Outsider · May 12, 2010

Re: 10w40 in Outdrive

0w40 and a typical 80-90w gear oil are actually very similar in thickness

Wheel bearing grease and peanut butter are similar in thickness, too. What's that got to do with anything?

bhammer · May 12, 2010

Re: 10w40 in Outdrive

He is going to buy the Four Winns. They negotiated on the price a bit better, the Seller dropped the price by another $800. If the drive fails between now and 1 year, the Seller will pay the full price of an SEI outdrive. That will be in writing. The Buyer feels that if he, read me, changes the gear lube he should be fine.

The Seller must be an honest guy because he said that well, no sense in starting this all over again, because the next buyer will want to do the same thing and change out the drive. Heck, if it were me, I would change the drive lube to what it's supposed to be. If anyone were to ask, say I had a buddy give me a case of the drive lube.

Weather isn't the best for tonight so we will try first am for a sea trial.

xltier · May 12, 2010

Re: 10w40 in Outdrive

alot of trucks,such as chevy 3/4 ton 5 speeds r using 5 w 30 motor oil n the transmission.just rebuilt one for a guy and thats what chevy said to use.

fishrdan · May 12, 2010

Re: 10w40 in Outdrive

I'd pass, but it looks like it's all ready a done deal.

Heck, who knows, it might live... An old neighbor had a Merc (90-115?) tower-o-power that had a leaky LU. He told me he had been draining/filling the LU with ATF after every trip, until he could afford to fix the seals

QC · May 12, 2010

Re: 10w40 in Outdrive

HT32BSX115 said:
Ordinarily, I would agree with you except where it comes to hypoid gear oil vs motor oil.....

Stupid thing is I agree with you, but still think it wouldn't fail . . .

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