Dye For Oil


Jul 15, 2009
New Mexico USA
Is there a reasonably inexpensive commercially available (like available for retail purchase) dye that can be added to oil without diminishing the characteristics of the oil or interfering with its function?

I have a motorcycle transmission that leaks enough such that the oil is always clean, I will not be fixing the leak any time soon, and it's really tough to see the clean oil on the dipstick.

I will not be running any of the boutique transmission fluids that have dye in them already. They are sticky, they make a mess, they are not good for the secondary drive belt, they are expensive, and they don't work any better than regular motorcycle oil or HDEO.

Just looking for a dye I can add to the oil every now and then, 20w-50 in winter and SAE 50 in the summer.
The only dyes I know of I don't think add much if any color to the oil they're UV reactive for leak tracing, Valvoline VR1 is dyed blue but I think they recommend against it for wet clutch motorcycles.
Just found this --

it's a dye for hydraulic oil. Seems like it might work great, and a drop or two in a bike transmission should do it. Not looking for a leak, don't want to use a UV light, I just want to see the oil on the dipstick.

Doesn't seem like it could hurt motor oil in any way if it doesn't hurt hydraulic oil.
You could just rough up the dip stick where the oil level indicators are.
OR dye the end with Dykem Blue. It generally resists oil wash off.

My 2`¢
O’Reilly sells a full range of leakfinder dyes for ac systems, oil systems, etc. look for it near the ac stuff. If you don’t like oreilly im sure AutoZone, advance, etc. do as well. Just add a little each time. Cheap and easy.
Use a clean piece of paper towel as a blotter and lay the dipstick down on it without wiping, if you can picture that. Then compare the length of the oily spot on the paper against the dipstick hash marks.
I ran 70/90 weight gear oil in mine, and never had any type of leak. I never had to add any oil during 10k changes. And that's with nothing special gear oil from the auto parts store. Some friends of mine had more of a weep than a actual leak, running 20/50 oil.,,
... and it's really tough to see the clean oil on the dipstick.
In situations like that, I look at the dipstick under a light at an angle where I can see light reflect off the oil film.
Go to a hobby store like Michael's or Hobby Lobby and locate candle wax dye's, an oil soluble dye in small quantities. They come in at least four colors.
Thank you!

And not just for this, but all of your informed, well-educated, reliable, and eminently practical participation here.

But for this in particular, yes. This is what I was looking for. A simple, inexpensive, practical solution and an answer to the question I was asking.