Gear oil clarification

[planedick]

I have several posts about using "Gear oil" in the middle and final drives. I would like to let everyone know that these units both contain Hypoid gears. This means that the gears not only have contact points in the configuration, but they also have a sliding contact area. The specifications call for HYPOID gear oil and regular gear oil does not contain the needed compounds to keep the gears from wearing. Always use HYPOID gear oil in the middle and final drives.

[John]

I use Castrol 70w-90 Syntech synthetic in my middle and final drives. Have been for years. I have had no problems what so ever with it, other than it migrating past the threads of the fill, and drain plug, but a little pipe dope or teflon tape curses that.

[DiverRay]

I also use synthetic, but Red Line 75w90 gear oil. It meets ALL specs for the XS, and has given me plenty of life with little problems.( except water in the middle gear on the Solvang Ralley).
Ray

[Pat Kelly]

StaLube 80-90wt for "limited slip differentials". It's what I still have sitting around. Bought several cases long ago when I was 4-wheeling alot (crossing streams).

[prometheus578]

but a little pipe dope or teflon tape curses that.

I swear at my leaking fittings, too, but that doesn't seem to help.

[planedick]

With exceptions...

Seems we are using other types of oil that works just fine "except"..... Maybe the right oil won't boil over on long hard rides like DiverRay's on the Solvang ride or get hot and leak past threads. Maybe we should read the specifications in the manual and use the right stuff. Having engineering experience with hypoid gears, I sure will.

[DiverRay]

The boil over on mine was caused by water in the middle gear that I DIDN'T remove when I did the first oil change. The second time, I CLEANED the middle gear out, and my 85MPH at 118 degree run through the desert didn't do anything. Bike ran great the 7,200 miles this past summer, and the oil level was at the fill point when I changed it again.
Ray

[Crazcnuk]

If you check I think you will find all the oils mentioned above ARE hypoid oils.

[John]

The Castrol bottle doesn't say anywhere on it that it a Hypoid oil, but it is recommended in all automotive differentials, and most of them have hypoid gears. Don't they?

[oseaghdha]

hype oid?

Found this:

Oils with "EP" ratings (Extreme Pressure) such as EP90 are required.
Some brands describe themselves as "hypoid" instead, a term which is
synonymous with EP. GL-5 is a formal API standard for this type of oil
(comparable to MIL-L-2105B/C/D)

[planedick]

Auto's differental..

No, auto differantials are not hypoid. Hypoid gears are found in most outboard motor bottom gearing. Hypoid gears allow the drive gear to drive the driven gear at other than the center. It also allows for much more contact area so we can put the massive HP of the XS in such a small area.

[Crazcnuk]

The ring and pinion gears in most auto differentials is a hypoid gear set.

http://gemini.tntech.edu/~slc3675/me361/lecture/grnts4.html

[planedick]

Real clarification....

Well, the can of worms is now open. The original post was to clarify some post that said to use 90 WT gear oil when the manual says hypoid gear oil. The gear set is not really hypoid, but the pressure from the XS beast probably warrants the special rating. The gear set is really spiral bevel gears. I am amazed at how many people here have tried to change my mind about the proper oil by saying they have used XXXX for XXX yrs without problems. As I stated in the beginning, 90 WT gear oil is not what the manual specified. Period. I don't give a dam what you all use. I will continue to adhere to the manual because I want mine to last forever.

As you see, sometimes I can be a real ass. I get better at it with age.

[TopCatGr58]

Some more clarification

I am amazed at how many people here have tried to change my mind about the proper oil by saying they have used XXXX for XXX yrs without problems. As I stated in the beginning, 90 WT gear oil is not what the manual specified. Period. I don't give a dam what you all use. I will continue to adhere to the manual because I want mine to last forever.

Hey Dick,

As with other topics here, most folks are NOT trying to change your mind, or tell you what to do or not do! They are merely sharing their experiences with other techniques, similar products, etc. that worked just as well as the "officially recommended" products.

We welcome your expertise and knowledge, but others here are also knowledgeable, and have previous experiences that shouldn't necessarily be discounted. It's at their own choice and possible peril whether they heed any advice given here on XS11.com.
T.C.

[Crazcnuk]

Re: Real clarification....

Originally posted by planedick
Well, the can of worms is now open. The original post was to clarify some post that said to use 90 WT gear oil when the manual says hypoid gear oil. The gear set is not really hypoid, but the pressure from the XS beast probably warrants the special rating. The gear set is really spiral bevel gears. I am amazed at how many people here have tried to change my mind about the proper oil by saying they have used XXXX for XXX yrs without problems. As I stated in the beginning, 90 WT gear oil is not what the manual specified. Period. I don't give a dam what you all use. I will continue to adhere to the manual because I want mine to last forever.

As you see, sometimes I can be a real ass. I get better at it with age.

I think the point is that almost any automotive gear oil IS a high pressure, hypoid gear oil that will work in the XS gear case.

The only place in any car that requires gear oil, at all, is in the differential which is a high pressure hypoid gear set that will take far more torque and stress than anything in the XS1100.

Take my Monte for example 567ftlbs of torque x (2.48 1st gear ratio x 3.73) differential ratio = 567 x 9.176 = 5203ftlbs torque, at the rear axle! Then multiply that by the rear tire size.... (1.5"axle x 27" tire = 18:1 x 4266 =93,654ft lbs!)

I think what I am using will take anything the XS100 can dish out and I use an 85W/90 synthetic of the shelf from Canadian tire.

http://yarchive.net/car/hypoid_gear_oil.html

Your only real question is what weight to use for your climate and application.

So unless your talking about a 90wt gear oil that is some wierd mineral oil for spur gear cases or something like that, it should work, but as you said better off to use an oil you KNOW will work!