Another Differential Question

[whitetaco02]

Okay, I am a newbie here and have a question. I have a Beast48 buggy and have noticed that I am getting a few drips on the concrete from the rear differential.

I just found the model and it says TXTPDS with a year of F0308 so I am assuming it is an EZ GO cart made in 08, correct?

I saw where most people dropped the rear diff pan, cleaned up the housing, used RTV blue gasket goop, added 10 ounces of SAE30 oil, jacked up both front and back to even it out and then bolted the rear diff housing back torqueing the bolts between 18-25 ft/lbs. As well as letting it sit and cure for 24 hours before driving it again.

Is that pretty much it?

I don't do stuff like this normally but it looks pretty easy.

Reason I ask is I have read some threads where some people used gear oil and I don't want to mess anything up. I have smelled the oil dripping from my diff and it smells nothing like gear oil but wanted to be sure.

Any preferences on the type/brand of oil.

Thanks again and awesome forum ya'll have here!

[usgicollector]

I don't use SAE30 oil. I use Valvoline Full Synthetic Gear Oil 75w90. I also use RTV made for gear oil.

[whitetaco02]

That's my dilemma. I am hearing too many mixed opinions on what oil to use back there.

[Dave Box]

There are two areas of confusion with regards to differential oil.

The first is that the SAE specs for engine oil and gear oil are different. This has led people to the erroneous conclusion that SAE 30 engine oil is less viscous (thinner) that SAE 75 gear oil and is therefore better suited to light applications such as a golf cart. The truth is that they are, as near as makes no difference, the same viscosity.

The second problem is that EZGO (and possibly others) use SAE 30 engine oil in their differentials. I believe that this is simply a cost cutting method which streamlines their purchasing and adds to the bottom line.

Engine oil and gear oil are formulated for different tasks. Engine oil has detergent in it while gear oil has additives to compensate for shear stresses. Multigrade oils become more viscous as they become hot. This heating does not happen in a differential so using for example a 5W-30 Multigrade would certainly be incorrect.

I guess looking at the big picture it is only a golf cart and you could probably use mayonnaise if you really wanted to (ok just kidding here). You should do what you think is right for you or simply follow the instructions in your manual. I will always use gear oil in gear boxes because it is the right thing to do, others may have a different opinion.

The only exception that I am aware of is if you have a limited slip differential which requires special additives and then follow the manual to the letter.

Dave

[Gregorio]

I'm with Dave. All oils lubricate moving parts but they do it differently. Engine oils have modifiers and detergents to combat combustion byproducts and raw fuels. Gears oils contain specific modifiers that prevent boundary lubrication problems. This is created by power transmission between two moving gears in gearboxes and differentials. The extreme pressure wipes the lubricating film completely off the metal. The sliding action of helical and hypoid gear sets are always wiping their mated surfaces clean. One of the biggest difference between the two kinds of oil is that 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. Most engine oils do not have anti-foaming agents or enough of them. Because bubbles are not oil, there is less lubrication of the friction surfaces. Oils rated GL4 are the current minimum requirement for gearboxes but GL5 are much better.

[cgtech]

Use gear oil, i would go with GL5. If the motor is oily, or the area just below it, that would indicate a input shaft seal leak. I like to use Yamahas "problem solver" kit on all dana electric axles (part number "99999-JU200"). It includes a o-ring seal, a new sealed bearing, and a oil slinger to keep the oil off the sealed bearing, where it serves no purpose except to invite oil leaks.

[whitetaco02]

It is definitely coming from the seal of the differential cover. I did what was recommended and used straight 30 weight oil since I called Beast and they confirmed it with me. My problem is it is still leaking but when I put the cover back on I leaked a little on the RTV so I feel like that hurt me. It is definitely coming from that area it leaked when reinstalling the cover. Looks like I am about to do it all over again. This is frustrating!

[Gr8hntr]

Just run a good line between the bolt holes and around each bolt hole with the RTV .. if the RTV runs on you let the cover sit for a few minutes to get a little firmer
good luck

[whitetaco02]

Okay, I just dropped the pan, got everything cleaned up, resealed it with RTV and then re-torqued all bolts to 22 ft/lbs.

I will put the oil in tomorrow once the RTV has had time to cure.

Here is my question: When I looked in the bottom of the pan it looked as if there was glitter in the bottom due to the shavings. There were no big chunks at all and everything looked okay in there from what I could tell. It drove fine before I drained it as well with no unusual noises.

Does this mean I should have used gear oil? I used straight 30 weight oil as recommended by many on here as well as from the mechanic at Beast Buggy. There is no oil in there right now so I am in a perfect position to add what I need and right now I am leaning more towards gear oil. Can somebody please point me in the right direction?

[whitetaco02]

Originally Posted by Dave Box

There are two areas of confusion with regards to differential oil.

The first is that the SAE specs for engine oil and gear oil are different. This has led people to the erroneous conclusion that SAE 30 engine oil is less viscous (thinner) that SAE 75 gear oil and is therefore better suited to light applications such as a golf cart. The truth is that they are, as near as makes no difference, the same viscosity.

The second problem is that EZGO (and possibly others) use SAE 30 engine oil in their differentials. I believe that this is simply a cost cutting method which streamlines their purchasing and adds to the bottom line.

Engine oil and gear oil are formulated for different tasks. Engine oil has detergent in it while gear oil has additives to compensate for shear stresses. Multigrade oils become more viscous as they become hot. This heating does not happen in a differential so using for example a 5W-30 Multigrade would certainly be incorrect.

I guess looking at the big picture it is only a golf cart and you could probably use mayonnaise if you really wanted to (ok just kidding here). You should do what you think is right for you or simply follow the instructions in your manual. I will always use gear oil in gear boxes because it is the right thing to do, others may have a different opinion.

The only exception that I am aware of is if you have a limited slip differential which requires special additives and then follow the manual to the letter.

Dave

How do you know if you have a LSD?