RXV rear axle oil--how to install?

[cgtech]

The axle installed on the assembly line used only silicone sealant, so I use only silicone.

[localbar]

Originally Posted by cgtech

Ok, looked up the numbers, i was wrong. A few different fluids have been used by ezgo in the rxv (they are hesitant to admit it tho). The correct amount is 740cc or 25 oz. Of all the fluids they used, my pick is 75-90 gear oil (quietest operation). My pick for fluid (because it meets all requirements, already has friction modifier for Posi, and i always have it in stock) is actually a Yamaha product called "friction modified shaft drive gear lube". Its a 75-90 GL-5 with friction modifier (part number "ACC-SHAFT-LU-00"). I actually use my own concoction of Lucas oil stabilizer (roughly 50%), Yamalube (roughly 50%), and 2 additional oz of friction modifier (available at auto parts store) totalling 25oz. The reason for extra friction modifier, Some rxv posi units were a little noisy when cold, while turning, at low speeds (they will always find something for me to fix). The Lucas says its ok for Posi, but a little extra friction modifier for "insurance" has never caused me any trouble. You can go to the parts store and get 75-90 GL-5 and friction modifier. Just "yamalube" is fine for the lubrication and "posi" needs tho.

Is there a reason not to go with 80w140 which is what the owners manual states?
Or is there a better reason to go with 75w90?

I plan to use Royal Purple 80w140 and add another oz of posi trac as you suggested in this thread.

Can one over treat since Royal Purple already has this additive included?

[Alex D]

Originally Posted by localbar

Is there a reason not to go with 80w140 which is what the owners manual states?
Or is there a better reason to go with 75w90?

I plan to use Royal Purple 80w140 and add another oz of posi trac as you suggested in this thread.

Can one over treat since Royal Purple already has this additive included?

It probably makes no difference. EZ-GO is quite confusing about this. The TXT rear end which has the same gears and housing, just no limited-slip in the punkin is supposed to be filled with 12 oz. of 30 weight motor oil. 30 weight motor oil and GL-5 70W-90 gear oil have about the same viscosity. The RXV calls for 27 oz. of axle fill with 85W-140 GL-5 oil and limited-slip additive.

My opinion. These rear ends don't suffer the heat and high torque loads of truck diffs. so I think the 80W-90 is fine but I don't think you would hurt it with 85W-140. They are also slow-turning gears. i think GL-5 oils are better than motor oils because of specific high-pressure additives for hypoid gear lubrication.

[localbar]

My Amazon order for Royal Purple 85/140 that was suppose to be here for the weekend is now delayed and I was hoping to do the service this weekend (vacation home)

My options at Walmart are:

80/90 mineral oil
75/140 full synthetic (with Friction modifier)
85/140 mineral oil

I have posi trac friction modifier on hand.

I will say 85/140 and 80/90 feel about the same thickness (shake test)
And 75/140 full synt feels noticeable thinner (shake test)

I bought all three and will return what I don’t use.

Which one should I go with?