Final Gear Oil

[Jerry W]

I am needing some help on which final gear oil to use. My owners manual says to use GL-4, but I am not having any luck finding it. All I can find is GL-5 and by what I can find on the internet, that is not compatable with GL-4 service. I have heard that it is ok to use GL-5 if it is a synthetic, however I can't find that on any manufactures web sites.

 

Do any of you know about this? I would appreciate the benefit of any research you have done. Thanks.

[Freebird]

This is what I use.

 

http://www.mobil1.com/USA-English/MotorOil/Other_Products/Mobil_1_Fully_Synthetic_Gear_Lube_75W-90LS.aspx

[Jerry W]

Thanks, their product data sheet states that it can be used when GL-4 is recommended. I appreciate your help. I will be buying some Mobile 1 tomorrow.

[Rick Butler]

Guys,

 

Just something else to consider. AMSOIL came out with their severe gear extreme pressure lube just this past year. And they have it in 3 grades (75-90,-110 and -140) and they all are GL-5 and GL-4 compatable.

 

http://www.amsoil.com/storefront/svo.aspx

 

Rick

[dray]

Guys,

 

Just something else to consider. AMSOIL came out with their severe gear extreme pressure lube just this past year. And they have it in 3 grades (75-90,-110 and -140) and they all are GL-5 and GL-4 compatable.

 

http://www.amsoil.com/storefront/svo.aspx

 

Rick

i use the 75 90 amsoil GL 5 GL 4 good stuff:thumbsup2:

been out longer than that i been using it in my boat lower unit for at least 5 years the 75 90 that is it dont foam so its good for boats to wont build perisher in lower units

[Locomotive]

Jerry, any Wal-Mart or auto parts store will have the gl-5 rated differential fluid you seek. Generally 80/90 wt is a gl-5, and some that are more expensive will have an additive for limited slip diffs' which will not cause any issues. Just read the back of the label and it will say gl-5 rated suitable for use in Hypoid gear apps, etc. Most pick ups use gl-5. Good luck:322:

[V7Goose]

I, too, jumped through hops to find GL-4 when I did the first service on my RSV. I had lots of GL-5 on the shelf (needed for the limited slip diff in my truck), but the manual called for GL-4. I also knew that GL-5 was not compatible with some metals used in certain transmissions, although the details now escape me.

 

Anyway, after I finally found the GL-4, I was re-reading the user's manual and found a note that specifically stated GL-5 was acceptable. Not sure exactly where that was now, but it is in there!

Goose

[83 decked out]

same here I changed the fluid using rotella 80w90 from walmart says gl5 but manual says ok I believe to use any 80 weight oil when hypoid gl4 isn't available. Afterwards I found gl4 hypoid at a bike shop for 13.00 a quart i think i like rotella 4.00 quart:322:

[heatonmt]

Freebird could you tell me how long you have been running the Mobil 1 75w-90ls. Has it had clean drains when you changed it. thanks

[Freebird]

I've been running it for about 5 or 6 years and usually change it once per year. It's dirty when I change it but I've seen no shavings or anything.

[windrider1983]

Does the above recommendations apply to the 1st Gens? I have an 83 and preparing to do the rear wheel maintenance as noted in the forums. It was changed about 6 or 7 years ago by a bike shop when I had the tire replaced, but don't know what they put in it. I did not see any reference to GL4 on the Mobil1 spec sheet at this time.

[cowpuc]

Yeppers..