Gray Oli in Transmision case

Hi, Im Cory Kiger I have a 03 CRF 450. Im 15 race in 250B, 4 stroke,And open B/C in District 5. I use honda red transmission oil in my tranmission but after raceing/riding hard it steams and drips out grayish oil from the transmission overflow, and i was wontering what is turning the red transmission oil gray??


Don't you just hate it, when it's your first post, and you type in "oli" instead of "oil" as the SUBJECT??

I wouldn't worry about it too long, however, because you can probably whup my butt, and several others here, on the track.

Hey, welcome to TT. I hope others have a better technical answer than I just did. I've had my CRF450R for 6 months, and haven't had any problems with the tranny oil. I change it about every 5 to 6 rides.

Mine was greyish OIL :) too. No big deal, it's just break in.


If your talking about that hose that has a plug in it, that's normal for some muck in there. I flipped out at 1st when I saw this, but you have to drain this every once in a while. If that's what your talking about. :)

Cory, so a search on the subject. There were a few threads about this topic in the past 6 mo that may be of some help.

Good luck!

It could be the clutch basket dampers. If your clutch gets real hot once (or more times) it breaks down the rubber that honda uses and they start to disentegrate. Best way to check is to pull the basket out and feel for radial play between the ring gear and the basket. This is a pain to do, you have to remove the whole right side engine cover.

This problem was supposed to be fixed in the '03s but I've heard of at least one '03 with the problem.

Look for rubbery chunks in your oil. If your seeing those, this is almost certainly your problem.

I just bought my 03crf 450. My buds ride yz250f's so I have learned from them what not to do. If you look in the owners manual it will tell you about differant oils to use in your bike and the make up of the mixing between the crank side and trans. side. this mix if you are using two differant oils may be your prob. I used the chart and found that I can use the same oil that I use in my Ducati. I use syntex 5w-30 for both. make sure you get the red top. If you read your book it will tell you about the stamps on the back of the oil bottles and gives you an example of the stamps not to use. I change my oil when it gets dark enough that I cant see the holes in the sight glass. It works out to be about 3 rides (This is also the number you will get in the book) some times two. I know what you are talking about when it comes to grey oil all to well. So far I have not ran into that problem yet. Also when I picked up my bike from the Honda shop it had an out the door servic done on it. Well first time out it chattered real bad in the gear box. I put about 8hrs on it and changed the oil (after reading the book). the chatter is gone. I hope this helps but like I keep saying read the book. This bike is picky about things and for once Honda put out a manual that covers most it with out buying a shop manual to go along with it. I hope this helps.

Will water in your trans will make it look gray?

The grayish oil is normal. Mine still does it after about 15 hours of riding time. It's slowly fading back to what oil should look like.

That's cool that you're 15 and on a CRF450. My son is 14 and a little scared of my 450, but I keep telling him he can handle it. Welcome to TT. JED

yes, water and oil mixed will turn grey.

Keep a close eye on your coolant both for level and cross contamination from oil. If it's clean and the level doesn't change, then don't worry about grey oil. If you notice crap floating on the top of your coolant and/or the level is going down, then it is very likely you have a bad water pump seal.


Its aluminum from your clutch drive plates. Change your oil sooner!


The cluthc plates in the CRF450 are steel and not aluminum like in the CR250's. I would look to see if maybe you have a leak in your cooling system. If it is milky, it is most likely water mixing into the oil.

I meant to say the clutch plate separators. Oops?!?

Is it possible for water to get inside the transmission during washing or creek crossings?

Two friends of mine w/ CRF's found gray oil (or water in it).

Seems I remember a post on this before, but a search didn't turn up anything.

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