REAR AXLE LUBRICATION

[jgtibbs]

In trying to puzzle out the inner workings of an EZGO rear end: I removed the rubber plug on the bottom of the oil pan (underside of the gearbox) on my 2009 EZGO RXV...and out came about 16 oz of oil. I had hoped that little if any oil would come out, i.e. that this "opening" was actually an access hole to check the oil level in the gear/clutch(?) housing. In this expected case, the oil would fill the protruding cavity on the underside of the oil pan to provide the lubrication needed for the gears/clutches with the "access hole" allowing for a "finger" check of the oil level. So, time to regroup.

My guess is as follows: (Assuming the rear end had the proper amount of oil (27 oz. total, including 2 oz of friction modifier per EZGO), the 16 oz that poured out of what now appears to be a drain hole was, in effect, oil retained in the axle shaft housing to lubricate the axles...with the remaining 13 oz (give or take) held in the oil pan for gear/clutch lubrication.

Is my guess correct? I'd greatly appreciate some comments on this, since I am very new to gold carts and have found nothing yet that paints the complete picture of how this rear end assembly is designed to function. And, since there is no obvious Fill hole to complement the Drain hole, I'm guessing that the design guys, in this case, were smokin' left-handed cigarettes.

One ray of sunshine: The "vent" on top of the driver side rear axle can be used as a Fill hole; a little tug and out it comes - pop it back in after filling. And, if the design guys thought to put in a vent, wouldn't they think to put in a fill plug?...or at least identify and use the vent as a fill port?....is it possible that there is a good reason for this, other than cost? if so, please advise.

[Michael Eddie]

Hello jgtibbs,

I confirm that opening plugged with a rubber plug is indeed the oil check opening. If fluid ran out, it was overfilled. Though this hole was also meant to be a fill hole, using the vent hose hole instead or also would not damage anything I suppose, since it leads into the exact same chamber as the designated fill hole.

Dealer says this rear holds just a hair under 25 fluid ounces of gear oil. If using an additive, substitute additive for gear oil (I.E. 23 ounces of gear lube and 2 ounces of additive = Total 25 fluid ounces).

[jgtibbs]

Thanks Michael...what you say makes good sense to me. In fact, all common sense and good design practice virtually demands that the rubber "plug" on the underside of the oil pan be an access opening for checking oil level, and definitely not be either a drain hole or a fill hole. Even with negligible oil pressure, having a pop-in "rubber stopper" containing usable machine oil just isn't done in my experience.
However, I was somewhat "thrown off the scent," so to speak, by my conversation with a technical guy at EZ-GO in Augusta...are you ready? He said that the "plugged hole" was both a fill and drain hole. In order to "fill" the gearbox, one must jack up the rear end of the golf cart by about 30 inches in order to add oil without it flowing back out, and you can bet money that I wasn't going to do that. My guess is that this guy was having a little fun with a newbie golf cart owner. To add insult to injury, this gentleman added that the "vent" was just a vent and not to be used for adding oil. Yes, I know, but I couldn't make this kinda stuff up.

To put all this to the test I will remove the oil pan, clean it, reinstall it and then add 25 oz.(total) of oil and verify, or not, that oil does not pour out the "access" hole and that this hole functions as expected, i.e. an access port for checking oil level. I will report back on the result.

[Michael Eddie]

Thanks, keep us posted whatever the outcome