Too much metal fragments in final drive oil

Savago

Savago

Joined
Mar 7, 2017
Messages
131
Location
California
Bike
ST1300@2009
Dear friends

Today while changing the faulty K&N filter in my ST1300@2009, I decided to also change the final drive oil.

About the bike: I bought it with 8K miles and it has now about 12K miles.

The final drive oil looked relatively clean, no signs of contamination *but* I noticed a lot of metal fragments (more like a fine metal dust really) on it as also in the drain plug magnet.

Is it expected?

Photos:
IMG_20171126_132852.jpgIMG_20171126_131001.jpgIMG_20171126_131414.jpg
 
Probably just break-in wear , that's what magnet is there for as a filter ....

When the rear end has a grinding noise going on constantly , that is when you know you have something worthless , like my new BMW R1200RT had , besides some more serious problems
, at less than 6K miles !
 
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I would think not, but I've read here that you can expect some of that in the first oil change of the final drive, and never again. I'd change it, ride the bike for a month or two and change it again and inspect the oil.

My FD had no such metal in the oil but it did have excessive clearance (aka gear lash) and caused a clunk when shifting. I bought a used one on ebay for $100, so they are not expensive. Mine was not the cheapest one available, but I needed one with the ABS sensor bracket. Since this thousand dollar part is so inexpensively available used, I'd not worry about it more than keeping an eye on it.
 
I can tell you that the FD oil I drained out on Friday was black as night and shimmering from the microscopic size metal from wear.

It was the oil the PO said was only 2000 kms old however I do not believe that.
I'm going to change it again in another 1000 kms. For the few ounces of oil it's cheap to make sure it's fresh.


Sent from my iPhone using Tapatalk
 
The final drive parts are very likely assembled with a moly assembly lube. That is the black part. As the parts wear in, there will be some very fine material as well, perhaps shiny. After some mileage, this will taper off to near zero as the gears are now bedded in to each other. Your first oil change will get rid of a lot of the darkness, some residual will be there until the next time which is not a problem. Anyhow, normal, get some sleep and ride well.
 
Savago said:
About the bike: I bought it with 8K miles and it has now about 12K miles.
Click to expand...

The inspection interval for the final drive oil is 8K with replacement at 24K. Your bike probably had the lube that was put in it at the factory which will, as Ray covered, have the assembly lube and shavings from the initial wear-in. Nothing to worry about.

Or if you want to panic, I'm fine with that, too. :)

--Mark
 
Like mentioned... changes are easy ( always loosen top first :) no need to over tighten as they have an oring , must have had a lot of left over 750 honda valve covers ) then oil will be cleaner after a couple of changes due to moly.
 
Given the mileage and history of the bike this is probably the first change and everything is normal. If you are concerned just ride the bike until it at normal temp and change out the gear lube again. Time and cost to do this is minimal. This will flush out any remaining fine particles from the break in and you'll see in future that oil is lighter in colour and that the magnetic drain plug has a relatively small amount of sludge on it.
 
Guys

Thanks you all for the feedback, I feel much better knowing that it is normal.
:)
 
After you get that original oil and bits out of there it will stay a lot cleaner with a good quality gear oil. I change mine every oil change as it is only a little oil to fill it.
 
Honda uses some kind of molybdenum assembly grease in the original assembly, so the lube always looks dark at the first fluid change. Molybdenum is a metal particulate material and can reflect light. I think this moly additive is often mistaken for metal shavings. Finally if manufacturers didn't expect some wear debris as normal, they wouldn't use magnetic drain plugs.
 
With my '95 model, I had changed the final drive fluid 4 times over 75,000 Km. and always found some metallic "goop" stuck on the magnet each time. I was using Castrol Hypoy C 80W-90. At that point I switched to a synthetic gear oil (Castrol Syntec 75W-90) and on the very next oil change, I was quite surprised to find the magnet clean upon removal. Proved the value of synthetic to me right then and there.
 
Bush said:
With my '95 model, I had changed the final drive fluid 4 times over 75,000 Km. and always found some metallic "goop" stuck on the magnet each time. I was using Castrol Hypoy C 80W-90. At that point I switched to a synthetic gear oil (Castrol Syntec 75W-90) and on the very next oil change, I was quite surprised to find the magnet clean upon removal. Proved the value of synthetic to me right then and there.
Click to expand...

When I changed mine the first time, at about 30k miles, I talked to the owner of Maxima oils. He said use a synthetic oil, change it once and forget it. Told him I was planning on putting 100k+ miles on the bike, he said so what, change it once and forget it. Maybe 10-12 years later with close to 100k miles on the bike I decided to change it again, just in case. As I recall there was just a very tiny bit of metallic goop on the plug.
 
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