Different differential fluid fills? (pun intended)

[Alex D]

Does anyone know why the TXT rear end is supposed to be filled with "only" 12 oz. of lube and the RXV with 25+2 oz. of lube/additive? The dana housings seem to be the same in size and capacity, so why would one take twice the amount of lubricant than the other??

I am changing my fluid in my TXT and was going to dump 25 oz. of 80W-90 GL5 in there.

[Alex D]

Well, little "opinion" here. Lifting the rear of my golf cart with my high lift floor jack I was able to get 18.5 oz. 75W-90 gear oil into the diff via the fill/check hole before it ran out. That should do it.

[E-Z-come]

I just filled my marathon via the plug and only got 8oz in before ot was running out.

[Alex D]

Originally Posted by E-Z-come

I just filled my marathon via the plug and only got 8oz in before ot was running out.

I jacked the rear of the cart up with my long reach high rise floor jack ... probably a 25 degree angle and got 18.5 oz. in before it started running out.

[rib33024]

Your not doing it any good by over filling it

[Alex D]

Originally Posted by rib33024

Your not doing it any good by over filling it

It's not overfilled. THe TXT and RXv have exactly the same Dana housing, gears and pan. THE RXV has an LS diff mounted to the large gear. That's the only difference. The specs on the RXV are 25 oz. + 2 oz. friction modifier because the LS diff needs apparently more lube. So min. fill is 12 oz. and max fill is 27 oz. all are ok for TXT. For RXV you need 27 oz fill.

[E-Z-come]

I’m not sure why if the procedure for filling is via the plug I’m not sure why the required quantity would be more than could be put in, in the manner the manufacturer calls for

[JohnnieB]

Originally Posted by E-Z-come

I’m not sure why if the procedure for filling is via the plug I’m not sure why the required quantity would be more than could be put in, in the manner the manufacturer calls for

The limited slip differential used in RXV and other AC drive carts calls for 25oz of Mobile 424 lubricant, or equal.

Earlier versions didn't have a high mounted fill plug and you had to pull the driver side axle and run a filling tube through the axle housing into the gear housing, then pump in 25oz of lubricant. (See attached page from RXV service manual)

The open type differential used in non-AC drive EZGO carts from about 1988 to present, only calls for 10oz to 12oz of lubricant. The factory fills them with SAE 30 motor oil, but many of us prefer to use gear oil to lubricate gears. I have no idea why EZGO chose to use motor oil to lubricate gears.

Also attached is a drawing that shows a open style differential and contains some torque specs as well as the assembly being canted towards the front about 5° and specifies the volume of lubricant needed in text at lower right. The text is too small to read since the JPG is only 14.4% of the actual drawing size (10,660 x 4,660 pixels), so I included it full sized in PDF format for those who are interested.

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Personally, I don't think it hurts to run more than 10-12 ounces in the open style differential. The limiting factor being a level that will stay lower than the bottom of the axle tubes on the steepest hills you'll be encountering with your cart. Get lubricant in the axle tube and it'll eventually get on the brake shoes and you'll have to hit something to stop your cart.

[Alex D]

SO Johnnie this is where I struggle with the info ... Why would the fill level of 25 oz. be okay for the RXV Dana unit but not for the TXT unit when, regardless of fill plugs or not, these units are identical except the LS diff mounted to the large ring gear in the RXV unit vs an open diff mounted to the same ring gear in the TXT unit. This makes absolutely no sense to me. If the oil level is an issue in the TXT Dana, it is as well in the RXV Dana.

I get that the RXV call for gear oil plus additive because of the LS clutch pack and that 30 wt motor oil can be substituted for gear oil (probably being a much better lube because of the high-pressure additives in gear oil) in the TXT units.

But from a capacity perspective I see no reason why 25 oz would not work in a TXT Dana while they are spec'd for the RXV Dana

[JohnnieB]

Like I said, the max fill is limited to a level that won't get oil in the axle tubes.

I've got an eyebolt in the bag well and a chain fall in a shade tree. Hoisted rear of cart until there was room to get under it comfortably, putting the pan at an angle and pumped gear oil in until it came out of fill hole. Probably have someplace between 12 and 16 oz in it.