CrownEE

My old (1977) Austria made Puch has served me for many years but now has what sounds like grit in the freewheel asm. I removed and I am trying to "wash" it out with fuel oil. I was advised that taking it apart is a bad idea. So what is the best method of cleaning these?

Thanks

MichaelW

If its not worn out, then flushing is a good way to clean.
I place the freewheel large cog facing up over a small plastic margarine container.
Locate the gap between rotating parts and drizzel solvent in. I use WD40 but kerosene also works. Fuel oil is too heavy.
Rotate a few time, Leave to drain then drizzel bike oil in.

cny-bikeman

Any solvent that you would use for chain cleaning works. I think WD-40 could get expensive if there's much to clean out. I would soak it first, then flush. I'm not sure why the previous poster suggested large cog facing up. The path is usually more direct for contaminants to exit through the rear, so I have always flushed from the small cog side.

furballi

I use gasoline and an old toothbrush. Be sure to stay at least 50 ft from any open flame.

MichaelW

I feel a endian war coming on.

cny-bikeman

Well, gasoline will ignite from a spark, even static electricity, and could do so wherever you dispose of it. A toothbrush is not going to clean the exterior, so this might not be the best advice to follow.

CrownEE

After I get it cleaned out, what would be good to lube it with? I thought maybe some spray lithium grease but I'm not sure it will penetrate.

Suggestions?

cny-bikeman

I like Phil Tenacious oil or some other high viscosity waterproof oil. I prefer to avoid grease for a variety of reasons.

canopus 

Funny, I've used this method for 30 years without issue.

+1 on the Phil Tenacious oil.

Asi

for a quick job i remove the freewheel, and submerge it in gasoline/diesel (or alcohol, but gasoline or diesel works better), after that I let it drip and clean it with a rag, and then install the freewheel on the wheel, put the wheel on the bike, and spin the rear wheel and while coasting you can pour into the small ring, some thick mineral oil (like 75W90). Trough capillary action the oil would be sucked up into the mechanism. It is advised to lean the bike on the non-drive so the oil won't spill.

Otherwise I usually dismantle it to check for wear also.

BCRider

Mineral spirits or Varsol cleaning solvent is a lower ignition point product that is safer than gasoline. Also the fumes are not as hazardous as with gasoline. Something to think about for long term exposure. In any event any time you're washing parts in solvent it's smart to wear solvent resistant gloves and avoid skin contact as much as practical. There's short and long term medical issues associated with excess solvent skin contact.

Definetly do not squirt grease of any sort into the freewheel. It'll gum up the freewheel ratcheting pawls and give you fits. A medium to thick body oil is the only thing to use. I prefer something like the 75W90 (think really thick like mollases) thinned with a bit of the mineral spirits or even a dollop of lacquer thinner. Thinning it allows it to flush through and and drain to leave a nice light coating on everything without any excess to drool out of the freewheel over the next few rides and onto your pants, floor or bike. And after the solvent evaporates away to leave the thin oil coating the use of the thicker oil should produce a nice quiet sound.

If after all the solvent flushing and oil wash it's still gritty feeling then it got rust into it and the bearings are damaged. At that point it's time for a new freewheel.

TassR700

Another option for lube is Quicksilver synthetic lube for boat lower units. It is the right viscosity and water resistant. It has worked well in free hubs and free wheels for me. I always have some around due to my boat.

chandltp

Don't you want a higher ignition point?

BCRider

Just checking to see if anyone was awake...

Of course you're right. My bad.

CrownEE

I'm surprised that Quicksilver or 75-90W is used. I guess I would have thought it would be too thick and would mess up the freewheel action. Some day I'll have to open one of those to see what makes them "tick" (pun intended).

Excellent ideas, thanks to all.
Tonight I'll see if I can get it cleaned out and lubed so I can get out and ride this weekend.

JohnDThompson 

Spray grease is unlikely to penetrate deeeply enough to properly lubricate the mechanism. There is a tool to assist with this:
https://www.velobase.com/ViewSingleTo...a-cee9ac8683e8

cny-bikeman

One note I would make is that some freewheels have black plastic shields that must be carefully pried off in order to allow proper flushing.

CrownEE

Mine did not have a plastic cover and was reasonably easy to flush. It just took some time and a pint of mineral spirits. After that I used Quicksilver boat lower end lube that I had left over from helping my bro with his boat. Let it soak in, spin it around, soak in some more and voila it works like new. Put it all back together and it works like a charm. Now on to the next ......

Thanks for all the help

dedhed

I like to do a spray of brake cleaner after the solvents to get it all out. The brake cleaner evaporates and won't dilute the lube.