lower unit gear oil

ecs17a

Cadet
Joined
Nov 7, 2010
Messages
18
Hello all,
I just drained my lower unit 90 hp Merc 3 cyl.I see that 80w 90 is the viscosity for replacement.Ive got a Quart of 80w 85 Honda 2 stroke motorcycle trans/gear oil.Would this be ok to use?It is red in color unlike the yellowish black that came out .
Thanks
 

Timestep

Petty Officer 1st Class
Joined
Jul 17, 2002
Messages
204
Re: lower unit gear oil

All SAE 's are not created equal. Also the Marine oil will be more suitable for, well, err, a Marine enjoinment.

Don't risk it for a few bucks.

Regards

Dave
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: lower unit gear oil

Also, some of the LU lubes don't mix well. It might have had Merc HP lube in it. What color was the drained lube?
 

Moody Blue

Captain
Joined
May 24, 2004
Messages
3,136
Re: lower unit gear oil

Hello all,
I just drained my lower unit 90 hp Merc 3 cyl.I see that 80w 90 is the viscosity for replacement.Ive got a Quart of 80w 85 Honda 2 stroke motorcycle trans/gear oil.Would this be ok to use?It is red in color unlike the yellowish black that came out .
Thanks

I don't understand questions like this. How would we know if using a non-recommended TYPE of oil, in an application that it is NOT intended for, would be OK to use :confused:.

Use whatever you want in there, it's your motor. You know what is specified, you assume the consequences. What should be used is MARINE grade lower unit lube.

Would you put diesel in your gas tank because that's what you have laying around? 2 cycle oil instead of 4 cycle oil your car? Don't think so.
 

ecs17a

Cadet
Joined
Nov 7, 2010
Messages
18
Re: lower unit gear oil

Also, some of the LU lubes don't mix well. It might have had Merc HP lube in it. What color was the drained lube?

The drained lube was black/brown.I think Ill just get the Quicksilver and be done.I had a feeling I got bad advice from someone about using this oil in my motor , just thought I would run it by you guys(the experts).Thanks for the reply.Any other tips would help.

Thanks
 

ecs17a

Cadet
Joined
Nov 7, 2010
Messages
18
Re: lower unit gear oil

I don't understand questions like this. How would we know if using a non-recommended TYPE of oil, in an application that it is NOT specified for, would be OK to use :confused:.

Use whatever you want in there, it's your motor. You know what is specified, you assume the consequences. What should be used is MARINE grade lower unit lube.

Would you put diesel in your gas tank because that's what you have laying around? 2 cycle oil instead of 4 cycle oil your car? Don't think so.

Hey Moody Blue,
Maybe a simple answer like no would have been better.Telling me to "put it in if I want to"was lame.Do us all a favor and dont reply to any more stupid questions from us "Cadets"
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: lower unit gear oil

Hey Moody Blue,
Maybe a simple answer like no would have been better.Telling me to "put it in if I want to"was lame.Do us all a favor and dont reply to any more stupid questions from us "Cadets"

You just wound up on my "ignore" list.
 

chum1

Petty Officer 1st Class
Joined
Apr 15, 2010
Messages
359
Re: lower unit gear oil

Hey should i put valve lapping compound in my motor because i think it is too tight?
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: lower unit gear oil

well thats discouraging.I certainly meant no disrespect to you at all.

Moody blue, though he probably hasn't aced diplomacy 101, tried to point out to you the logical fallacy or mistaken reasoning that would make you seek approval for a non approved application from perfect strangers, and then you dissed him. Think about it.
 

ecs17a

Cadet
Joined
Nov 7, 2010
Messages
18
Re: lower unit gear oil

Hey Moody Blue,
Maybe a simple answer like no would have been better.Telling me to "put it in if I want to"was lame.Do us all a favor and dont reply to any more stupid questions from us "Cadets"

In refection,I guess my question was a bit unusual.Its just that I was told by a boat yard guy that it would work and I didn't trust him.My response to you was out of line and came before my first cup of coffee.So please accept my apology
thanks
 

ecs17a

Cadet
Joined
Nov 7, 2010
Messages
18
Re: lower unit gear oil

Moody blue, though he probably hasn't aced diplomacy 101, tried to point out to you the logical fallacy or mistaken reasoning that would make you seek approval for a non approved application from perfect strangers, and then you dissed him. Think about it.

Your right.My bad.I dont need any enemies here so my apology to you also.
 

Moody Blue

Captain
Joined
May 24, 2004
Messages
3,136
Re: lower unit gear oil

In refection,I guess my question was a bit unusual.Its just that I was told by a boat yard guy that it would work and I didn't trust him.My response to you was out of line and came before my first cup of coffee.So please accept my apology
thanks

No worries, I understand. My keyboard etiquette is a little rough sometimes. Didn't mean to come across so crass.

We're all in the same boat (so to speak) on these forums. We're learning as we go, and its better to ask a dumb question than it is to make a dumb mistake.
 

Dave1027

Lieutenant Junior Grade
Joined
May 25, 2010
Messages
1,080
Re: lower unit gear oil

Hello all,
I just drained my lower unit 90 hp Merc 3 cyl.I see that 80w 90 is the viscosity for replacement.Ive got a Quart of 80w 85 Honda 2 stroke motorcycle trans/gear oil.Would this be ok to use?It is red in color unlike the yellowish black that came out .
Thanks
I understand your reason for asking. You thought because both oils say 2 stroke they might be interchangeable. The factory manual states "Quicksilver outboard oil recommended". You may substitute a good quality "marine" gear oil. I use the Walmart brand marine gear oil.

The motorcycle stuff does not have the additives that counteract water intrusion and make it marine grade.
 

mercury713

Petty Officer 2nd Class
Joined
Aug 22, 2010
Messages
100
Re: lower unit gear oil

Its like car diff gears it will work.

Last time I looked a gear was a gear and a seal was a seal.
 

redjmp

Chief Petty Officer
Joined
Mar 16, 2005
Messages
536
Re: lower unit gear oil

It will work fine as long as your seals are not leaking. But when they do start to let water in, that lube doesn't have any emulsifiers to mix with the water and you have a much shorter window before serious damage is done. In a pinch it will do as long as you check it often and replace it with marine rated lube as soon as you detect any water. Mercruiser always recommends using their grossly overpriced maintainance products, but any marine rated lube will work. However when you do get signs of water in there, that would your cue to not only change the lube, but the seals as well.
 

ecs17a

Cadet
Joined
Nov 7, 2010
Messages
18
Re: lower unit gear oil

I understand your reason for asking. You thought because both oils say 2 stroke they might be interchangeable. The factory manual states "Quicksilver outboard oil recommended". You may substitute a good quality "marine" gear oil. I use the Walmart brand marine gear oil.

The motorcycle stuff does not have the additives that counteract water intrusion and make it marine grade.

Yea thanks,
this stuff seems to have everything you could want in a gear oil except the emulsifier for the water intrusion.Its HP 2 stroke racing trans/gear oil.Even though its not listed as an ingredient,I wonder if it has it.I was on a couple rooms where moto heads had talked about getting water in their gear cases.maybe they change this oil more frequently.I will use MARINE grade oil but for fun Im going to ask a Honda tech this question.

Thanks,
Eric
 
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