Oil in sealed Shimano 600EX freewheel
 

I had to really clean to get rid of significant grime on the cogs and every nook and cranny it seems. Rust was less of an issue.

Once clean, I use 3 in 1 oil like I usually do with freewheels, but with the seals, it doesn't seem to be seeping in. Would prefer not to take apart a freewheel if I can avoid it, but eek, the noise... if cleaning it removed the gunk inside, it would seem I could replace it with some new gunk...

My freewheel...well not my freewheel, but the model...

https://cimg7.ibsrv.net/gimg/bikefor...3b4f17a897.jpg
Add some decay and it is mine...

I was messing with one of these last week. I got to use a Stein freewheel injector for the first time. I was easily able to flood the mechanism with Phil's oil. A lot of crap came out with the over flow of oil. So I'm going to re flush with mineral spirits.

https://cimg6.ibsrv.net/gimg/bikefor...5df171078.jpeg

If it is making a great deal of noise, it is probably really gunky on the inside. Take it apart and give it a proper cleaning, grease the races, and add a few drops of oil on the pawl pivots.

Any suggestions on how to get the plastic cover ring off with out destroying it?

NOOOOOOooooooooo.......

I know you are the freewheel yogi, but any shorter cut to get it lubricated?

:innocent:

The "cover" comes right off, it's reverse-threaded.

Just remove the cover, put in 30 drops of oil and spin it a few times as the oil works it's way down to the last ball bearing race.
Then just leave it in a warm location to drain out overnight on a rag, there is no seal to prevent oil from draining out from the back side.
I use motor oil.

Sometimes I whirl the freewheel to get the excess oil through in a hurry, stresses my arm though.

I really like these Shimano Uniglide freewheels. Very reliable and easy to maintain, plus they give the very best friction-shifting experience for spirited riding imo.

If you decide to paint your house, would it be acceptable to paint prior to proper cleaning and preparation of the surfaces to be painted?

You can ignore what you can't see (the internals of a freewheel) but can apparently hear. You can slop oil into it on top of rust, other contaminants, and possibly something even worse (a broken pawl or bearing) or---- :innocent:

Just my two cents worth of advice given with all sincerity and a great deal of experience having serviced 1000s of freewheels. YMMV.

Those freewheels have an oil port on the body, so you could flush solvent through that port and maybe avoid the need to open the body. Access to the oil port is done by removing the sprockets:

Thank you @JohnDThompson and @pastorbobnlnh

Darn, no matter how you slice it, I have to open it up. Ugh...

The locking cog is reverse threaded, right? Have to find a pin spanner online I guess....

The lockring should be reverse threaded. The smallest cog should be forwards threaded.

If this were not for the Clunker Challenge, I'd be putting this in the "to-do Box of procrastinate repairs)"...time to count ball bearings I guess...

It's not a lock ring, the part that you can see, thoughg there is a lock ring with a bearing cone machined into it's back side underneath the plastic cover/shield.

I've seen shielded "600" freewheels where the actual lock ring had "Z" stamped into it, as if the actual core/body of a 600 freewheel is an ordinary (but none-the-less excellent) Z freewheel.

Both the shield and the lock ring are reverse-threaded. The plastic shield takes little torque to remove (can be removed with a nail and a small hammer) and should not be tightened heavily at all or will strip.

I prefer a lighter spin so use 10W-30 oil in all my freewheels. No problems to report, though I have had cheap Sunrace freewheels and later-year very cheap Suntour freewheels that would develop a creak when the oil in the races eventually went missing because of the "flow-through" ventilation afforded by large clearance openings on each end of the freewheel body (some later-years, inexpensive freewheels can even trap water and dirt under their cog retention ring due to poor design, and which then acts as a "hopper" to force-feed the elements through the freewheel body!!!).

No need to count bearings.

To Clean: Spill them into plastic bowl or dish (my favorite is a left-over yogurt cup). Include the pawls, the spring, and any shims. Be careful with the shims, Shimano uses some extremely thin ones (almost foil like). Spray with WD-40. Swish. Blot with paper towels to soak up the excess WD-40. Add a generous amount of Dawn Dish Detergent and a small amount of extremely hot water. Swish. Swish more. Swish a third time. Strain the soapy water from the bearings (I like to use a loose tea strainer). Rinse in lots of hot water. Place in over at 200F to dry.

Re-Installing Bearings: Add a thin layer of grease to the top (chain stay side) race on the outer body and a thin layer of grease on the bottom (spoke side) race on the inner body. Place the bearings and fill each race until no more bearings can fit. Add a couple of drops of high-grade machine oil to the pawl pivots and rub the ratchet teeth with oil. Reassemble.