Final Drive Oil

I have watched a couple of videos showing how to change final drive oil. One mentioned hypoid gear oil. However, my factory shop manual says to use Honda GN-4 motor oil. There is a vast difference between 80-90W hypoid gear oil and motor oil. What is the consensus here about this?

Use the same oil you use in the engine.

Motor oil

This topic has been discussed here several times with no final resolution.I believe Honda has elected to use engine oil to keep things simple.Back in the early seventies when the catalytic converter
first arrived on the seen they found the oils that contained Zinc(used for high load area's) was clogging up the converters.
To eradicate this problem the engineers decided to replace the flat tappet camshafts and use roller camshafts. There was a very high degree of camshaft failure before the engines were re-engineered.
Hypoid gear oil still has Zinc in it and does not go by the same SAE
standards as regular engine oil.80/90 gear oil is about the same viscosity as SAE  30 weight engine oil. Most racing engines use Zinc
additives in there oil even though they use roller camshafts.
As they say, what ever floats your boat.    Howard

Hello fellow riders,
 In my 06 I mix 10W 40 with Lucus engine oil stabilizer, 1 part Lucus and 2 parts 10W 40,
It has to help as it is some slippery stuff. The only bad part is my thumb gets cramped up
pumping the oil can getting it in there.
   Lar

I like motor oil containing a bit of molybdenum. You really only need to add moly once after that the working surfaces have the stuff in the pores. Moly was what saved the Honda Goldwings. The early wings had early drive shaft spline failures. Honda tried adding a zerk fitting near the splines but that didn't solve the problem. The advent of Moly Paste, 60% molybdenum ended the problem. No more spline failures. While the SW doesn't have splines in the drive line it does more or less in the final connecting the gears. Moly really does help reduce wear in gears straight cut or hypoid which have a wiping action. I put motor weight AMSOIL synthetic with a bit of moly paste added for the finals on the two SWs I had. I'll add a bit in the chain case on my 650GT as well pretty soon. Amsoil gear oil keeps my K1100LT shifting smoothly, would have been nice to have in my GW if it had a dry clutch like the BMW.

Cosmic_Jumper wrote:

Use the same oil you use in the engine.

I second this! Usually do final drive oil every 2nd oil change!

Use engine oil as per Honda. As it is pain to change (bad design). Mine might get changed every belt change---Wal Mart 10-40, I think SilverWing has any history of gear train failure.

I agree with John but only to a point. It seems an easy procedure to me. I used JeffR pictorial and have no problems. So I do this every other oil change...

I don't believe one needs to change the final drive oil very often. Engine oil becomes contaminated with combustion byproducts including acids and moisture due to blow by in the cylinders. The final drive doesn't have much to cause break down or acids in the oil so should last quite a long time. If it looks good, not black or fudgy it's okay. How often does one change the oil in a car's manual transmission or differential?

john grinsel wrote:

Use engine oil as per Honda.   As it is pain to change (bad design).   Mine might get changed every belt change---Wal Mart 10-40,

I agree it's a pain to change, at least it was for me! Poor design. Seemed it got air locked easily due to the small orifice where the oil goes in. I had more oil on the floor than went into the hole! I used a small hose as per plan to squeeze the oil in. I changed it one time only, hopefully that will be good for a lifetime.

I changed mine last month using a 100ml syringe with a piece of plastic hose attatched, it was easy to do but still messy. Any overfill found it's way down between tthe filler hole and the casing and dripped down. It was good experience for next time but as the old oil that drained out was clean and clear I can't imagine me doing it too often.

Once again JeffR's pictorial was useful.

I doubt if mine was ever changed in the first 9 years until I changed it and it was clean and better yet no metallic shine seen. I used 85 W hypoid oil just as the G'wing did, probably the last time it will get changed. This different lube than OEM isn't anything new in bikes or even tractors I put 85 w in everything but the engine and hydraulic system when I changed fluids in my 45 year old International, they used hydraulic fluid in everything but the engine why ? as their forum stated because it was one fluid fits all convenience and it did the job, but hydraulic fluid in a steering gear box?? The good of that change was it shifted dramatically better after the change and now 13 years latter it's still better.

GHM-PM wrote:

I agree with John but only to a point.  It seems an easy procedure to me.  I used JeffR pictorial and have no problems.  So I do this every other oil change...

Hi Glenn,

Please send or forward the pictorial from JeffR regarding final drive lubrication.

Thanks,

TomG

P.S. Personally, I agree with Xavid about the need for frequent oil changes.

TomG here is the link:

Final Drive

GHM-PM wrote:

TomG  here is the link:

Final Drive

Glenn,

Thank You, Thank You, and Thanks. Excellent description.

I think 85 W is a little heavy as the bike is designed to use 10-40. Just my 2 cents worth. Dave

Update to an old topic. I used 10W-40 in mine 10K ago. Planning an extended trip in September so checked the final drive level. The oil looked pretty bad so to play it safe I drained it. As stated above it is easy but messy. This time I am going to try Castrol 80W-90 hypoid oil. See if this does any better. There were some particles in the oil when I drained it so I am glad I replaced it.

Hi Guru,

I replied earlier, but my computer ate the reply I think.

Isn't 80w-90 Hypoid a bit too viscous for the SWing final drive? And, what improvements do you expect with the heavier oil? Just curious about your thoughts on the subject.

Wow, an amazing discussion. Here, there, this, that.

Per the Ketchup (Catsup) advisory board I'm filling my picnic table ketchup bottle with the recommended engine motor oil, squirting it in there through some excess aquarium air tubing, and moving on. Great discussion. Love this place.

Ketchup...Ketchup....

Jon

Service manual recommends 10-40

Where exactly ? On pages 1-5, 3-11, and 4-1 the Service Manual recommends 10w-30. Both the Service Manual and Handbook say 10w-30 oil and both have a chart stating 10w-40 oil may also be used depending on the average temperature in your riding area.

I now realise I've posted this in the wrong topic! This is about final drive oil, not engine oil. It should have been in ’Need more info from and old post'.

You silly old git Meldrew!

Hypoid gears are beveled gears. I doubt there are beveled gears in SW drive as a change in drive direction is not required as with shaft drive.

The best place to find information on gear design,oils and the why-fores is Wikipedia.Being a gear head in the 1955 to 1990 and to much time on my hands I did disassemble the the final drive on my 06 S/W to take a look. Very basic and of decent design. It does have a input shaft a counter shaft to change rotation and a out put shaft which connects to the rear wheel. I believe the most important aspect on what type of oil to use is that it has oil.
In a previous post the merits of the types of oil used and the effects of some additives on Catalytic Converters and the result to changes in engine design. At GM Motors they went from W 80-90 to ATF with no problem with standard transmissions due to the type of oil used.
Howard

Reg wrote:

Hypoid gears are beveled gears. I doubt there are beveled gears in SW drive as a change in drive direction is not required as with shaft drive.

You are exactly "Right", and for the "Right" reason. Two rear wheel turn at different speeds, thus the term Differential. And, yes, a drive shaft is part of the equation too.

Hypoids are not only bevel gears they are Helical Bevel gears thus allowing more tooth engagement. Further, the hypoid pinion (drive member) is positioned off-center (lower) from the ring gear (driven member) for space saving purposes.

No need for Hypoids on two wheeled vehicles.

NWSSC wrote:

The best place to find information on gear design,oils and the why-fores is Wikipedia.Being a gear head in the 1955 to 1990 and to much time on my hands I did disassemble the the final drive on my 06 S/W to take a look. Very basic and of decent design. It does have a input shaft a counter shaft to change rotation and a out put shaft which connects to the rear wheel. I believe the most important aspect on what type of oil to use is that it has oil.
In a previous post the merits of the types of oil used and the effects of some additives on Catalytic Converters and the result to changes in engine design. At GM Motors they went from W 80-90 to ATF with no problem with standard transmissions due to the type of oil used.
Howard

Thanks, Howard.

I used some Redline 10W40 engine oil. Loaded with with good stuff. High in Anti-wear additives. Zink Phos.
Gear oil is thick when cold. Choose a engine oil over gear oil.

Ride on.

Most commercial oils have a minimal amount of zinc dialkyldithiophosphate as an anti-wear additive to protect contacting metal surfaces with zinc and other compounds in case of metal to metal contact. The quantity of zinc dialkyldithiophosphate is limited to minimize adverse effect on catalytic converters.

Redline is is high in Zinc Phos around 2000 Parts per million .
Newer car oil is 600-800 at best. PHOS is what destroys converters.

If auto makers could make engines that didn't use oil wouldn''''''''t be a concern.
Everything is only made to last so long. Price point, VS profit.
WARR is 8 years 80 thous on most emmision parts. USA.

I don't get it, how does the oil in the final drive effect the catalytic converter?

Well gremlin, Honda recommended there engine oil to be used in the
final drive to keep things simple. There oil like many other manufactures does not contain as much additives as they previously had and there fore it is not as good as it used to be for high load areas. Not saying it will not work,it is probably just a matter of
preference. Howard

I spoke with the Honda Dealer shop manager about the issue of gear lube vrs engine oil in the rear drive. Dan the manager said it doesn't make any difference what you use and only use a 75/90. The bearing run on plenty of oiling surface and using engine oil in the rear was Honda keeping everything straight forward. Use what you like it all is good.

Next time it is time to change that final oil, Use straight 30 wt motor oil, It is non foaming and try my method. While the final is draining after the removal of both plugs and the flush out with brake cleaner. Find that piece of clear vinyl tubing that fits in the lower drain hole, Fill that squeeze bottle that the 90wt. came in with the 30 wt. engine oil, Attach the other end of the vinyl tubing to the squeeze bottle, Apply pressure on the upside down squeeze bottle until the oil begins to come out the upper fill hole. Pull out the Vinyl tubing from the lower drain hole, Use a finger to stop the flow until you can install the drain plug. If any oil came out the top fill hole clean the area and install the upper plug. You are now an expert at changing Final oil with no mess. Happy Motoring lloyd 193.

Why not follow Honda recommendation on oil. Remember some people live where it is cool/cold.

lloyd193 wrote:

Next time it is time to change that final oil, Use straight 30 wt motor oil, It is non foaming and try my method. While the final is draining after the removal of both plugs and the flush out with brake cleaner. Find that piece of clear vinyl tubing that fits in the lower drain hole, Fill that squeeze bottle that the 90wt. came in with the 30 wt. engine oil, Attach the other end of the vinyl tubing to the squeeze bottle, Apply pressure on the upside down squeeze bottle until the oil begins to come out the upper fill hole. Pull out the Vinyl tubing from the lower drain hole, Use a finger to stop the flow until you can install the drain plug. If any oil came out the top fill hole clean the area and install the upper plug. You are now an expert at changing Final oil with no mess. Happy Motoring lloyd 193.

Basically the method used to change stern drive oil in a boat!  You can even buy a pump at Walmart etc. to make job easier.

https://www.walmart.com/ip/Attwood-Gear-Lube-Pump/16351021

john grinsel wrote:

Why not follow Honda recommendation on oil.   Remember some people live where it is cool/cold.

John Grinsel, the Multiple viscosity oils are usually High detergent oils and create foam which will exit the Final case at high operating RPMs, By using a non Hi Detergent oil this problem is solved. If you want a thinner oil in your cold climate, Use a lower Viscosity oil like 10 Weight. Happy motoring lloyd 193.

I filled mine with SuperTech 75W-90 synthetic blend gear oil at 9100 miles, now at 16k miles and do not anticipate any issues. I ran the same fluid in my '03 Burgman 400 for 60k miles.

As to viscosity, 75W-90 "weight" gear oil has approximately the same viscosity as 30W engine oil, and is specifically formulated for gear drives, not engines...


The SAE J300 "grade" system was first developed in 1911 and though it has been updated continuously--the last update being in May of 2015--The various "grades" are now much better defined however they are still only loosely connected to viscosity, and are more "rule-of-thumb" labeling standards for vehicle maintenance and consumer information.

A strong argument could be made that they should be abandoned as for many manufacturer's recommendations of same have become immaculate proclamations never to be strayed from or questioned...

Some gear oils are not compatible with yellow metals. I'm not sure if there are any yellow metals in the sw final drive but if there are there could be problems ahead.
I think I'll just stick with Honda's recommendations.

Honda just says the same 10 w 40 you put in the engine.

steve_h80 wrote:

Some gear oils are not compatible with yellow metals. I'm not sure if there are any yellow metals in the sw final drive but if there are there could be problems ahead.
I think I'll just stick with Honda's recommendations.

There are none in the SWing final drive, it's all anti-friction stuff.

I haven't seen any in years even in automotive applications--some tranny synchro rings in the 60s and 70s were bronze. I had a '68 Fiat 124 Spider that had phosphor-bronze thrust rings in the LSD, it was last thing I owned with "yellow metal" in a tranny or rear-end...

DaveR wrote:

Honda just says the same 10 w 40 you put in the engine.

Hi Dave, A straight 30 weight non detergent oil is better in that final, It will not foam and blow out like the Hi Detergent oils will and it is easier on your seals and gaskets, Happy motoring lloyd 193.

gremlin wrote:

I don't get it, how does the oil in the final drive effect the catalytic converter?

It does not of course; however introduction of irrelevant "facts" is a vital component of disseminating FUD (Fear, Uncertainty, and Doubt), especially when you have nothing concrete to add to a conversation. Sort of like the "yellow metal" possible/maybe/who-knows? concern asserted earlier...

The yellow metals bit came about when I was researching final drive oils for my Tenere. Kind of irrelevant now someone has confirmed no yellow metals in ths sw final drive.

steve_h80 wrote:

The yellow metals bit came about when I was researching final drive oils for my Tenere. Kind of irrelevant now someone has confirmed no yellow metals in ths sw final drive.

I had to google "Tenere". That is a big-ass in-line twin, what components in the final drive are brass/bronze? I thought that sort of thing went away years ago.

Had a V-Max years ago; it was one of just two vehicles I have owned where I ran out of balls before it did...

I changed mine yesterday. As far as I know it is the first change. Very low miles on a 2007. It didn't look gooey and in hindsight could have gone longer. But I found the drain bolt came off too easy !!! probably not torqued too well. I replaced with gear oil, simply because I have a bottle of it on hand; I used it in my 2005, and noted a somewhat quieter drive.
I used a pliable drinking straw and strapped it with duck tape to a small funnel. Took me about 20 minutes waiting for gravity to do its bit. I stopped filling when it started oozing out of the hole.
I did refer to the pictorials on the site and Thank You Jeff for those clear instructions.
Jay.

cotetoi wrote:

I changed mine yesterday. As far as I know it is the first change. Very low miles on a 2007. It didn't look gooey and in hindsight could have gone longer. But I found the drain bolt came off too easy !!! probably not torqued too well. I replaced with gear oil, simply because I have a bottle of it on hand; I used it in my 2005, and noted a somewhat quieter drive.
I used a pliable drinking straw and strapped it with duck tape to a small funnel. Took me about 20 minutes waiting for gravity to do its bit. I stopped filling when it started oozing out of the hole.
I did refer to the pictorials on the site and Thank You Jeff for those clear instructions.
Jay.

I too found using gear oil made the final drive quieter--which is a good thing of course as something has to vibrate and use energy to make noise--reduced noise = less vibration and ∴ less misdirected energy...