Rear differential oil change

[teecro]

Originally Posted by theboss20

What about synthetic? Should you use a 30W in a synthetic ?

30W synthetic motor oil in the rear end of a golf cart? Without question....

Off Topic but I used a 15W50 synthetic motor oil in the gearbox of a Russian Ural Motorcycle for years... The factory spec as for 10W40 same as the engine.... I found that the Mobil 1 oil improved the shift quality greatly over the dino oil.... A lot of owners used an appropriate weight of gear oil without issue...

[bsa_bob]

Originally Posted by Gregorio

Motor oils are not the same as gear oils in composition and performance even at similar viscosity grades.

no no 30wt totaly different .

[Gregorio]

Originally Posted by teecro

Ok so what would you do then? The recomended oil is an SAE 30 API SG or higher...

Not sure why anyone especially the manufacturer would recommend an inappropriate lubricant. SG is a totally obsolete engine oil classification but I still would not use current (SN, SM or SL, IIRC) oils in a gear application. All oils lubricate but they do so differently. Engine oils need to combat combustion byproducts and raw fuels so they contain specific modifiers and detergents to do so. Gears oils contain specific modifiers that help combat something called boundary lubrication created by power transmission between two moving metal gears in gearboxes and differentials. The extreme pressure wipes the lubricating film completely off the mated friction surfaces. The sliding action of helical and hypoid gear sets have an even greater propensity to wipe the the surface clean. Most importantly, engines have oil pumps that eliminate the need for the oil to cling to the moving parts for dispersal. Gearboxes rely on some of the moving parts to be directly in the oil bath which can create a lot of foam. The bubbles reduce the amount of oil that is in contact with the friction surfaces. Oils rated GL4 are the current minimum requirement for gearboxes but GL5 are much better.

[theboss20]

So...I am still confused...Mobil 1 30w....o.k.?

[carguy]

5 or 6 years ago I installed high speed gears in our '05 Precedent. I refilled the rear end with Royal Purple straight 30W. Few month's ago I drained the lube & refilled with Royal Purple 30W. The drained oil did not have any metal pieces, chunks, and it was only very slightly gray looking, still easy to tell it was Royal Purple.

I run the car at 25 - 30 MPH all the time. If the car is rolling, the throttle is on the floor.

I will continue to use the Royal Purple. Other golf car owners are free to put what ever they want in their rear ends.

Have fun, Dave

[lockman1]

Originally Posted by theboss20

So...I am still confused...Mobil 1 30w....o.k.?

Yes!

[Gregorio]

Originally Posted by theboss20

So...I am still confused...Mobil 1 30w....o.k.?

Yes, it is just that, OK.

[geonjay]

Originally Posted by Gregorio

Not sure why anyone especially the manufacturer would recommend an inappropriate lubricant. SG is a totally obsolete engine oil classification but I still would not use current (SN, SM or SL, IIRC) oils in a gear application. All oils lubricate but they do so differently. Engine oils need to combat combustion byproducts and raw fuels so they contain specific modifiers and detergents to do so. Gears oils contain specific modifiers that help combat something called boundary lubrication created by power transmission between two moving metal gears in gearboxes and differentials. The extreme pressure wipes the lubricating film completely off the mated friction surfaces. The sliding action of helical and hypoid gear sets have an even greater propensity to wipe the the surface clean. Most importantly, engines have oil pumps that eliminate the need for the oil to cling to the moving parts for dispersal. Gearboxes rely on some of the moving parts to be directly in the oil bath which can create a lot of foam. The bubbles reduce the amount of oil that is in contact with the friction surfaces. Oils rated GL4 are the current minimum requirement for gearboxes but GL5 are much better.

What brand and type of oil do you put into the carts that you work on? It's time for me to change my diff oil...and I was getting ready to grab the Royal Purple...but I've learned the hard way to listen to YOUR advice in particular

[Gregorio]

I decided to use Redline MTL mostly because I had a ton on hand, it met the viscosity specifications and the needs of hypoid gears. Going on 2 years. Probably have a look later this summer.