Tips on cleaning 1969 L-46 fan clutch

[Kevin S.]

Good Morning,
Wondering if there is a best way to clean the cast aluminum fins and parts of a 1969 L-46 350/350 fan clutch. I'm not mechanically inclined enough to take it all apart and break it down.

I have been considering taping the shaft where it enters the internal bearing area and just using my gravity fed media blaster with 70 grit aluminum oxide to clean it up from a distance of about a foot. A far enough distance away to clean the surface and crevices of the fins without cutting too much. Did not want to get too close, or risk getting any media into the internal portion of the clutch where it would do damage. Clutch runs and works perfect now so I don't want to turn a cleaning project into a rebuild or replacement project. I also have Eagle One aluminum wheel cleaner. I've considered using that too and again being careful not to get any of the chemical inside the clutch where it could do damage and just use a toothbrush to clean the fins and crevices, hard to reach areas. I have Simple Green too and could just use that with soft brushes.

I like the way things turn out with my hand-held gravity feed media blaster but I'm smart enough to ask for adult supervision before I do something I will regret later so I am posting this Q&A.

Thanks in advance for the help.

Kevin

[Gary B.]

Richard Jones

505-897-6906

richardljones@comcast.net

Gary

[Rocco S.]

Re: Tips on cleaning 1969 L-46 fan clutch

Kevin,

I have had good success cleaning aluminim alternator housings using glass beads in my blast cabinet using a low, 40 psi, air pressure.You must degrease the part first to remove heavy dirt and grease before blasting. Otherwise you will just smear the grease.

You can buy glass beads at Harbor freight. Maybe you could construct some sort of box to reclaim the beads when using a gravity feed blast gun. Do not use aluminum oxide as it will "cut" too much and leave the aluminum surface frosty. I would also try to protect the seal. I use duct tape to mask areas as it holds up well to the air pressure and can be removed easily. Use solvent to remove any adhesive that remains after removing the tape.

Good luck and post photos when done.

[James G.]

Re: Tips on cleaning 1969 L-46 fan clutch

If you are anywhere that you could get something dryice blasted or vapor blasted it would nicely freshen up the housing without degrading the aluminum or destroying the surface finish.

The other suggestion of using glass beads at low pressure is also a very good suggestion too.

Do you know if the seal and bearing is good?

Reason I ask, if the unit needs to be rebuilt, Kirkconnel who rebuilds the Schwitzer Clutches nicely restores the housing when he does them.
FWIW the fan should not make more than one rotation after shutting the engine off.
After having mine rebuilt it moves air like a tornado.

[Joseph W.]

Re: Tips on cleaning 1969 L-46 fan clutch

Before I bought a media blast cabinet, I took mine to a carburetor shop. They glass bead stuff all the time.

[Kevin S.]

Re: Tips on cleaning 1969 L-46 fan clutch

Thank you, Gary. I will give him a call.

Kevin

[Kevin S.]

Re: Tips on cleaning 1969 L-46 fan clutch

Hi Rocco,
I have glass beads. I used those to clean a 1100 825 alternator case about a month ago. I saw your note on the 40 psi, I'll give it a try since I have everything I need and I have a good cleaner / degreaser too. I have a home-made working area behind my garage where I can capture the media and reuse it. I'll protect the seal with duct tape and clean the shaft area by hand with a green pad and dawn dishwashing soap. I have acetone for removing the duct tape residue if there is any.

Thanks for the tips.

Kevin

[Kevin S.]

Re: Tips on cleaning 1969 L-46 fan clutch

Hi James,
I do not know of anyone in my area that does dry ice or vapor blasting. I'm sure there are some, I leave near Charlotte Motor Speedway so there has got to be those services in this area. I've just never used it or explored dry ice or vapor blastiing.

I believe the seal and bearing are good. Fan clutch works perfectly. When I shut the car off, the 5-blade fan turns about 1 - 1.5 times and stops. Car has 56,000 miles and I believe it is original and has never been rebuilt.

Thanks for the suggestions.

Kevin

[Patrick H.]

Re: Tips on cleaning 1969 L-46 fan clutch

Hi Rocco,
I have glass beads. I used those to clean a 1100 825 alternator case about a month ago. I saw your note on the 40 psi, I'll give it a try since I have everything I need and I have a good cleaner / degreaser too. I have a home-made working area behind my garage where I can capture the media and reuse it. I'll protect the seal with duct tape and clean the shaft area by hand with a green pad and dawn dishwashing soap. I have acetone for removing the duct tape residue if there is any.

Thanks for the tips.

Kevin

I would first see if you can find anyone local who does the dry ice blasting.
For such a small item I think the cost would be reasonable, and it's a much less damaging process than any abrasive. In fact, it doesn't damage at all.

[Kevin S.]

Re: Tips on cleaning 1969 L-46 fan clutch

Hi Joseph,
I wished I had a blast cabinet. They are not that expensive at Harbour Freight. I just do not have the room for it inside my 2-car detached garage. You did give me an idea though. I know a guy (Jerry McCall) who restores alternators and he has a blast cabinet in his shop. I'll give him a call to see what kind of media he is using. He might be using glass media?

Thanks for the idea.

Kevin

[Jeffrey S.]

Re: Tips on cleaning 1969 L-46 fan clutch

I have used soda media in my blast cabinet to clean the surface of carburetor bodies and it does a nice job. The good thing about soda is that if it gets somewhere where sand or others will damage moving parts, the soda is harmless and can be washed away easily with water. On carbs, if it gets into a passage, the gas will simply dissolve it. It is a very mile abrasive. It can also be purchased at Harbor Freight. Just a thought.
Jeff

[Kevin S.]

Re: Tips on cleaning 1969 L-46 fan clutch

Hey Patrick,
I have a local sandblaster who I have used for leaf springs, rear stut supports, recently on my spare tire tub v-strap. They might know someone who does dry ice. I'll check with them.

Kevin

[Kevin S.]

Re: Tips on cleaning 1969 L-46 fan clutch

Hi Jeff,
Might have to check out the soda media option too. Harbour Freight is only about 10-miles from my house.

[James G.]

Re: Tips on cleaning 1969 L-46 fan clutch

There is at least one place in Charlotte that dry ice blasts...
Couple of Porsche guys I know took their cars from Greenville SC to CLT to have them done.

[Kevin S.]

Re: Tips on cleaning 1969 L-46 fan clutch

Group update,

- completed scubbing and degreasing the exterior of the fan clutch with dawn dishwashing liquid, then blow dry
- completed media blasting with glass beads after sealing and protecting the shaft where is enters the clutch
- found a 10-16-68 embossed stamp on the collar of the shaft, nice surprise after glass bead blasting. Car's build date is 10-31-68
- used dawn dishwashing liquid again after glass bead blasting to get clutch clean of dust, then blow dry again
- used a light coat of Very High Temp (VHT) satin clear to protect the fan clutch after blasting
- fan blades were media blasted 70 grit aluminum oxide, 2-coats of self etching primer, 2-coats of semi-gloss black
- bolts and lock washers were media blasted, (black) phosphate parkerized, and coated with Rust Prevention Magic (RPM)
- fan attached to clutch with bolts and lock washers, thread locker blue applied to threads, torqued to 110 inch lbs (per AIM)

Project turned out really nice. I appreciate everyone's input and suggestions, including phone contact for Richard Jones.

Kevin
KS69Coupe