Servicing Dura Ace Freewheel

I have this MF-7400 freewheel - very nice. It kind of stuck the other
day, didn't want to freewheel, and was turning the cogs when rolling
the wheel forward. It came loose and started ratcheting again when I
put a foot on the pedal and rolled the wheel, but it had been stuck
pretty good and didn't want to come loose with gentle hand cranking.

Today I got two chain-whips together and removed the cogs. There are
two holes, 180 degrees apart, in the freewheel body, which I think are
for injecting oil. I'm thinking I can use one of those little plastic
syringes to put the oil in the hole.

The freewheel seems to be in good shape, and has some oil in it, but
feels and sounds a little dry and gritty. It's been running in the
rain quite a bit lately.

Question: Do I want to soak or flush it first with like mineral
spirits, then let it dry and *then* squirt motor oil into those
holes? Or do I just start putting oil into it and flush it with that?

Oh yeah, one other question: I imagine I should grease in between the
cogs and splines and spacers and threads and all that when I put it
back together?

On Feb 28, 7:47 pm, Dan O wrote:
Question: Do I want to soak or flush it first with like mineral
spirits, then let it dry and *then* squirt motor oil into those
holes?
Yes. I would also warm it up once dry prior to adding oil. It will
help it flow into the nooks and crevices better, and might even flush
out a little more dirt.

Oh yeah, one other question: I imagine I should grease in between the
cogs and splines and spacers and threads and all that when I put it
back together?
It makes taking it apart again much easier, but it's not required. I
would though.

Chris

On Feb 28, 8:47*pm, Dan O wrote:
I have this MF-7400 freewheel - very nice. *It kind of stuck the other
day, didn't want to freewheel, and was turning the cogs when rolling
the wheel forward. *It came loose and started ratcheting again when I
put a foot on the pedal and rolled the wheel, but it had been stuck
pretty good and didn't want to come loose with gentle hand cranking.

Today I got two chain-whips together and removed the cogs. *There are
two holes, 180 degrees apart, in the freewheel body, which I think are
for injecting oil. *I'm thinking I can use one of those little plastic
syringes to put the oil in the hole.

The freewheel seems to be in good shape, and has some oil in it, but
feels and sounds a little dry and gritty. *It's been running in the
rain quite a bit lately.

Question: *Do I want to soak or flush it first with like mineral
spirits, then let it dry and *then* squirt motor oil into those
holes? *Or do I just start putting oil into it and flush it with that?

Flush it, let it dry, add oil. I use Mobil One auto synthetic oil.
Cheap and it doesn't get thick in the cold.

Oh yeah, one other question: *I imagine I should grease in between the
cogs and splines and spacers and threads and all that when I put it
back together?

Wouldn't hurt, may prevent some creaking.

Dan O wrote:
I have this MF-7400 freewheel - very nice. It kind of stuck the other
day, didn't want to freewheel, and was turning the cogs when rolling
the wheel forward. It came loose and started ratcheting again when I
put a foot on the pedal and rolled the wheel, but it had been stuck
pretty good and didn't want to come loose with gentle hand cranking.

Today I got two chain-whips together and removed the cogs. There are
two holes, 180 degrees apart, in the freewheel body, which I think are
for injecting oil. I'm thinking I can use one of those little plastic
syringes to put the oil in the hole.

The freewheel seems to be in good shape, and has some oil in it, but
feels and sounds a little dry and gritty. It's been running in the
rain quite a bit lately.

Question: Do I want to soak or flush it first with like mineral
spirits, then let it dry and *then* squirt motor oil into those
holes? Or do I just start putting oil into it and flush it with that?

Oh yeah, one other question: I imagine I should grease in between the
cogs and splines and spacers and threads and all that when I put it
back together?

Yes, use real oil. Yes, through the oil ports is the fastest way on that
one. Continue oiling and spinning in your hand until no more
crud/rust/swarf flows out.

No, do not use a volatile solvent. It will remove any remaining
corrosion protection from the pawl springs.

Yes, do lubricate cogs during assembly if you want to get it apart later!
--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Feb 28, 9:47 pm, Dan O wrote:
I have this MF-7400 freewheel - very nice. It kind of stuck the other
day, didn't want to freewheel, and was turning the cogs when rolling
the wheel forward. It came loose and started ratcheting again when I
put a foot on the pedal and rolled the wheel, but it had been stuck
pretty good and didn't want to come loose with gentle hand cranking.

Today I got two chain-whips together and removed the cogs. There are
two holes, 180 degrees apart, in the freewheel body, which I think are
for injecting oil. I'm thinking I can use one of those little plastic
syringes to put the oil in the hole.

The freewheel seems to be in good shape, and has some oil in it, but
feels and sounds a little dry and gritty. It's been running in the
rain quite a bit lately.

Question: Do I want to soak or flush it first with like mineral
spirits, then let it dry and *then* squirt motor oil into those
holes? Or do I just start putting oil into it and flush it with that?


I've always just dripped oil through them while spinning. Motor oil
has some detergents in it and will get the gunk out. Get whichever one
you like the smell of best. I'm a Castrol kinda guy.

Oh yeah, one other question: I imagine I should grease in between the
cogs and splines and spacers and threads and all that when I put it
back together?

Always good to do. Again, make sure to use a grease that compliments
your natural fragrance. I like the burly man smell of black grease.

On Mar 1, 7:34 pm, landotter wrote:
On Feb 28, 9:47 pm, Dan O wrote:



I have this MF-7400 freewheel - very nice. It kind of stuck the other
day, didn't want to freewheel, and was turning the cogs when rolling
the wheel forward. It came loose and started ratcheting again when I
put a foot on the pedal and rolled the wheel, but it had been stuck
pretty good and didn't want to come loose with gentle hand cranking.

Today I got two chain-whips together and removed the cogs. There are
two holes, 180 degrees apart, in the freewheel body, which I think are
for injecting oil. I'm thinking I can use one of those little plastic
syringes to put the oil in the hole.

The freewheel seems to be in good shape, and has some oil in it, but
feels and sounds a little dry and gritty. It's been running in the
rain quite a bit lately.

Question: Do I want to soak or flush it first with like mineral
spirits, then let it dry and *then* squirt motor oil into those
holes? Or do I just start putting oil into it and flush it with that?

I've always just dripped oil through them while spinning. Motor oil
has some detergents in it and will get the gunk out. Get whichever one
you like the smell of best. I'm a Castrol kinda guy.


I used Castrol 20-50 - that's what I had laying around.

Oh yeah, one other question: I imagine I should grease in between the
cogs and splines and spacers and threads and all that when I put it
back together?

Always good to do. Again, make sure to use a grease that compliments
your natural fragrance. I like the burly man smell of black grease.

I am still working on that tube of Lubri-Matic Marine Corrosion
Control and Trailer Wheel Bearing Grease.

Thanks a bunch to all for the excellent advice! (I'll go tomorrow to
the LBS and look for that "Shimano TL-PD40 SPD Clipless Pedal Axle
Removal Tool".)

Forecast is rain, rain, and more rain.