How do i check/add gear oil?

[whizzo]

A lot of people are under the misconception that thicker oil lubricates better.

Unfortulatrely that is not necessarily so.

Thinner oil will often flow into parts and places better and do other things better than the thicker oil.

Lots of applications are tending to run thinner oils these days..the old favorates 80-90 and 85-140 are rapidly being replaced by better engineered thinner oils even in fairly high load applications

85-140...hell that is slow heavy oil.

This whole SAE30 recommendation may be quite old too.

In times past ( long past for the young folk) SAE30 was more or less the standard oil for many things, everything from mixing with fuel for two stroke, used in engines, gearboxes and auto transmissions...the oil of the time was very low low tech and pretty well straight oil with no performance enhansing additives.

These days we have better oils for almost every application where it would have been spec'ed in the past.
Nobody in their right mind would be running SAE30 at 10:1 in their two stroke, the first dextron specification was a major leap forward in auto transmissions, purpose made gear oils came along and the modern multigrade engine oils are just so far ahead they make simple old SAE30 look inadequate.

So one of the modern light viscosity gear oils would be a good choice...if ya realy want to throw money at it one of the modern full synthetics would do the job very well.

But hell its a half tonne golf cart that even significanly modified will be maxing out at 20 Hp....more likley about 5 Hp continuous. AND its not like they run long and fast like full sized vehicle with similar sized diffs do.

So its hardly a highly stressed gear train handing a couple of hundred horses.

Almost any reasonable oil you put in there will work.....probably more important that the oil is clean and at the right level.

cheers

[JohnnieB]

I've been striving to eliminate misconceptions from my knowledge base for 70+ years.

In my opinion, SAE30 motor oil is not an adequate lubricant for the gears in my electric golf cart's differential, so I'm experimenting.

If Lucas 85W-140 gear oil reduces the top speed or decreases range, or other detrimental factor, I'll probably try 80W-90 or 75W-90 Synthetic, or other petrochemical brew.

It is a work in progress, so I have no idea where my experimentation will take me, but I'll enjoy the ride.

[catmcaw]

A few years back Harley started putting the same 20-50 engine oil in the trans and primary/clutch. They seem to think thinner is ok.
I guess I'm old and hardheaded and thin just don't cut it for gear oil.
One more thing that has me confused (it don't take much) , I'll use Red Line Oil 75W250 as an example. I think they make the best oil money can buy but heres how they describe it. "Film thickness greater than SAE 75W250 yet low fluid friction like 75W90". Kinda like sayin its thick but not really.

[JohnnieB]

Originally Posted by catmcaw

A few years back Harley started putting the same 20-50 engine oil in the trans and primary/clutch. They seem to think thinner is ok.
I guess I'm old and hardheaded and thin just don't cut it for gear oil.
One more thing that has me confused (it don't take much) , I'll use Red Line Oil 75W250 as an example. I think they make the best oil money can buy but heres how they describe it. "Film thickness greater than SAE 75W250 yet low fluid friction like 75W90". Kinda like sayin its thick but not really.

The devil is in the details.

Between SAE (Society of Automotive Engineers), API (American Petroleum Institute), ILSAC (International Lubricants Standardization and Approval Committee) and others, there are dozens of Types, Categories, Grades and Ratings for the performance properties of lubricants. And there is a lot of overlapping and grey areas in the mix.

One tricky part is that the viscosity of Motor oil and Gear oil are measured by different yardsticks. The viscosity of 75W-90 Gear oil is roughly the same as 10W-40 Motor oil, so 20W-50 motor oil will have about the same viscosity as 80W-120 Gear oil. If the 20W-50 motor oil meets the requirements for an API GL-4 rating, it should work fine in a Harley-Davidson transmission.

Many Motor oils have GL ratings, as well as GF (Passanger car), Sx (Gasoline) and Cx (Diesel) ratings, so read the labels closely.

[whizzo]

The other thing is...viscosity is not everything, and it is not as simple as it appears in gear oil.

Back in my youth, when you went into the auto shop or garrage to buy gear oil.....it was 80/90 or 90/140 and that was it, for diff or gearbox....if you had a new fangled japanese 5 speed you either ran the factory branded gear oil or engine oil.
These days there are at least 10 different gear oil types on the shelf at my local auto shop and the two old favorites don't sell all that well.

AND if you look at the quoted viscosities alone..there does not seem to be much in the way of difference.....get em out of the bottle and they do look a lot different.....get the wrong on in a modern vehicle and it may object in no uncertain terms.
I don't know how many posts I have seen about people putting the wrong oil in their gearbox and thinking its broken.

The engineering tolerances in the modern vehicles is much finer, and in some of them we are pushing a hell of a lot of power thru the transmissions.
The modern 4 cylinders are making more power than the small V8s of the seventies...and the larger motors proportionally more.

I recon any GL4 rated oil would be a safe choice and a better option than straight simple SAE30.

HELL where would you buy a simple SAE30 these days without paying way to much for an inferiour oil.

cheers

[yurtle]

A Golf Cart runs at WAY more "Slower" RPMs. Also, cars today last 200k Miles, while previous crap USA cars did lucky to last 100k, so the oils seem to be doing their jobs.

I'm not as old as JohnnyB, but have a few years of Japanese engine/oil experience, not to mention my industrial experience.

[smokey tennis shoe]

Before this turned into a technical class on oil viscosity, I wanted to be able to check the oil in a 2003 ezgo western rear end.

There is no plug of any kind, other than the one directly on the bottom of the pan. I would consider this a drain plug, but Johnny said it is also the place where you put oil in.

From the shape and design of the pan, it doesn't appear that I will be able to put much oil in this thing, but I will try.

I bought one of those transfer pumps ( JohhnyB) and will attempt to add some oil.

I did successfully replace the axle bearings on both sides. I looked inside the axle tube, and saw very little traces of oil in there.

I am hoping the oil is the problem, since the new bearings did not quiet the noise at all.

[rib33024]

if you want to change the oil and make sure everything is ok in there, this is how to do it



click on the link - pics and all you need to know

http://www.buggiesgonewild.com/elect...l-service.html

[smokey tennis shoe]

ok I will check that out. Thanks a lot for your help and time

[firenfix]

You can pull the pan, inspect and clean and then fill the lower recessed portion with oil and carefully reinstall with the oil in the pan, that's how I did mine and it was very easy. You can also pump the oil through the fill plug as the amount needed will fill the recessed part of the pan where the gear will pick up the oil. Either way will work fine for filling, however, you need to remove the pan to get the old oil out.