SAE 90 Gear Oil

[wh5208spee]

I have a older garden tractor (Wheel Horse) that has a gear drive transmission. The manual calls for a straight SAE 90 (GL-5). I have done a lot of searching and it is very difficult to find. If I went with the standard gear oils (85w-140 or 80w-90 or 75w-110), GL-5, which alternative would you use? What would be the downside to not staying with the SAE 90?

 

[Jimmy_Russells]

80w90 is the modern equivalent. It is just a bit thinner than straight 90 when it is cold (which is a good thing).

 

[Jetronic]

Can you find out which sae90 oil was recommended exactly? sae 90 has been split into sae90 and sae110 in recent years, so if they recommended a thick sae90 you could consider sae110 and be in spec.

 

[MolaKule]

I used to have a Wheelhorse and used a synthetic 75W110, a good wide temperature gear lube.

 

[mattwithcats]

Amazon.com: Honda 08739-90W Oil (90W Gl-5) : Automotive

Buy Honda 08739-90W Oil (90W Gl-5): Motor Oils - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[mattwithcats]

https://www.blauparts.com/ravenol-gear-oil-epx-90w-gl-5-1l.html

 

[mattwithcats]

This would be my choice…

PdsDetailsPage

Mobil Delvac 1 Gear Oil 75W-90 is a fully synthetic drivetrain lubricant engineered to meet very demanding extended drain and warranty requirements.

www.mobil.com

 

[wh5208spee]

Can you find out which sae90 oil was recommended exactly? sae 90 has been split into sae90 and sae110 in recent years, so if they recommended a thick sae90 you could consider sae110 and be in spec.

Here is the gear oil spec from the manual. In some of Wheel Horse's older tractors (but basically the same transmission), they use to recommend 90-140 GL-5. Not sure what caused them to change to the SAE 90.

 

[930.engineering]

80w90 is the modern equivalent. It is just a bit thinner than straight 90 when it is cold (which is a good thing).

80W-90 GL-5 not necessarily has same viscosity when hot compared
to older straight 90 GL-5 but I'd use 80W-90 GL-5 regardless. I'd also
use a 75W-110 GL-5 with confidence. Another 80W-90:

RAVENOL Getriebeoel SLG SAE 80W-90

RAVENOL Getriebeoel SLG SAE 80W-90 is high quality multifunction gear oil, bases on high quality solvent refined base oils and special EP-additives. Due t...

www.ravenol.de

 

[swampdodo]

Believe it or not, my '08 Sorento specifies straight 90W GL-5 oil. I called the local Kia dealership about this...they knew nothing of it (of course), and said to use 75w-90.

Although not available in my local area, it is **** near unobtainium...overseas.

 

[swampdodo]

90W gear oil is common, apparently, in the marine application...see below...but not sure of the GL ratings if any...

https://www.amazon.com/Star-Brite-Hypoid-Lower-Unit/dp/B002IV6IVO/ref=sr_1_1_sspa?keywords=sae%2B90%2Bhypoid%2Bgear%2Boil%2Bgl-5&qid=1644607034&sr=8-1-spons&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUE5REFDVTkySEg4QUImZW5jcnlwdGVkSWQ9QTA5MzEyNDAxUUlQOEcwUk8xOUZIJmVuY3J5cHRlZEFkSWQ9QTA0OTY3MTkyRUk0NEk1UzJIQ0dDJndpZGdldE5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ&th=1