Jump to content

SAE80-90 GL4 gear oil

Recommended Posts

Trying to ID best options available in NZ for saildrive and specifically if they are API rating GL4 or GL5. I want GL4.

I think Volvo 80-90 is GL5 but I can’t work out if Quicksilver is GL4 or 5.

Any advice on SAE80-90 GL4 gear oils in NZ?


Link to post
Share on other sites

The link I posted above is a long thread with some great info but here are a couple of example comments from others' experiences (and why I'm seriously considering ignoring Yanmar's ambiguous advice that GL4 or GL5 oil is OK):

"My own experience with our SD-50 was a unit that failed in just 2 years when using their recommended synthetic GL-5 oil. The replacement [GL4 spec] is still working just fine 11 years and thousands of hours and a second owner later.
It just needed the correct oil."

"[Yanmar] They actually specify either a Gl4 or a Gl-5 oil. 500 hours is about what we got using Gl-5.
Never had another issue once we switched [to GL4]. I’d pull the cone at 600 hours and couldn’t tell it from a new one once we switched.
It was not my first time finding this Gl-4/Gl-5 confusion by a major manufacturer. I was in the automotive industry and a lot of major manufacturers had the same issue. It appears to be pretty well understood these days."

"You are correct if you have an SD-50T, that sail drive uses a cone that is coated with a sintered finish that protects it from the GL-5.
My guess is that in the case of the larger engine/higher torque output they are concerned with wear in the gears in the lower unit. The GL-5 would be of benefit there.
If the cone is not a coated cone, don’t even think about the GL-5.
Our SD-50 had a sticker that was obviously attached during its manufacture that specified GL-4/GL-5."

Link to post
Share on other sites

Not related to the Saildrive, but in Vehicles, GL5 was not recommended for gearboxes. Diffs only. GL5 is heavily loaded with Sulphur/Phosphorus additives. Ruffly 2x more than a GL4. This additive destroys Bronze components in Gearboxes.
However, when it comes to Diffs, that is different again. As I found out the hardway with one of my commodores and the LSD. I did not realise at the time that Holden called for a specific Diff oil to be used, in which there was a special additive pack to suit that particular diff. I just used a good Diff oil made for LSD's. Not very long down the track and the Diff chewed itself to bits. I found that Penrite made a Diff oil with that specific additive pack in it and I have never had a problem again. It was researching the specs of Penrite Oils that I became so impressed with what oils they made and changed from Amzoil to Penrite, with the later being much easier and cheaper to get.
The SD gearbox is a lot more like a Diff than a gearbox. The cones have to be able to grip, yet slip just enough hen engaging a gear, that they don't create too much shock to the gearbox. Having too high an EP strength meant that the cones slipped too much.

Related to the type of oil used, the other very important point to ensure is the correct level of oil in any gear box. Over filling even just a little causes no end of issues.

Link to post
Share on other sites

I’ve now discovered that the most widely used by happy Yanmar SF owners seems to be Quicksilver but they do 2 versions of their 80-90 oil, GL4 and GL5. I’m now trying to source the GL4 version:



Link to post
Share on other sites

What I like about Penrite is it's online oil selection tool, you specify the vehicle and it defines the correct premium oil and then suitable alternatives. The range is very specific and applies to Australian and NZ models. This tool doesn't apply to marine units unfortunately.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...