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Posted by: Tdskip Jan 18 2018, 07:35 AM

Good morning. The 901 on my project has already been removed from the car. I need to open it up to replace the 2nd gear synchro and it obviously needs to be clear clean clean before I do that.

Is it safe to pressure wash the exterior case so long as I don’t spray where the input shaft is?

And been there / cleaned that tips to share?

Thanks!

Posted by: Front yard mechanic Jan 18 2018, 08:02 AM

Oven cleaner

Posted by: sdoolin Jan 18 2018, 08:04 AM

If you are careful around the seals, and tape the breather well, pressure washer will work. I did this a little over a year ago (pressure washer), with no ill effect. I was VERY careful.

Posted by: 914Sixer Jan 18 2018, 08:21 AM

Start out with a small putty knife and clean all that you can that way. It will make the overall cleaning go better

Posted by: rhodyguy Jan 18 2018, 08:28 AM

+ brake cleaner and a piece of 6mil plastic to work over. Multiple cans. Stinks to high heaven and puts you on the moon.

Posted by: cuddyk Jan 18 2018, 09:06 AM

First drain all the gear oil. I got a wood movers dolly and screwed some 2 x 4s across it narrower than the bellhousing (using long wood screws through the bolt holes to secure) so the transmission could stand vertically and be easily rotated to get at all the nooks and crannies.

Remove the speedo drive and block the hole. Tape up the vent well and put a tarp under the dolly/transmission as you work. it's a greasy mess. Like 914sixer said, use a putty knife to get all the thick junk. Then I used 4 cans of brake cleaner to loosen it all up. More expensive than oven cleaner, but it seems to work quicker. Then I removed the stub axles to get at the tight spots and used a steam cleaner to do the final cleaning (HF has em for under a hundred bucks and it's my new favorite tool).

Finally I painted with Alumi-blast and it turned out great. There's some disagreement as to how much paint (especially silver) contains heat, but I figure it isn't significant and protecting the box from the elements is probably better net-net.

If breaking the whole tranny down, I might consider having it dipped to save myself the greasy mess and my wife complaining about stains on the driveway;)

Posted by: Bartlett 914 Jan 18 2018, 09:08 AM

I use mineral spirits or naphtha and a small tray. I use a small bristle brush with the bristles cut short. Putty knife and small scrapers to get into cracks. I don't use brake cleaner in spray cans as much because I hate the spray coming back in my face. It also drys a little too fast. It works good as a last cleaner

Posted by: Tdskip Jan 18 2018, 09:20 AM

Thanks for the discussion.

Posted by: Tomgayer Jan 18 2018, 09:26 AM

QUOTE(cuddyk @ Jan 18 2018, 09:06 AM)

First drain all the gear oil. I got a wood movers dolly and screwed some 2 x 4s across it narrower than the bellhousing (using long wood screws through the bolt holes to secure) so the transmission could stand vertically and be easily rotated to get at all the nooks and crannies.

Remove the speedo drive and block the hole. Tape up the vent well and put a tarp under the dolly/transmission as you work. it's a greasy mess. Like 914sixer said, use a putty knife to get all the thick junk. Then I used 4 cans of brake fluid to loosen it all up. More expensive than oven cleaner, but it seems to work quicker. Then I removed the stub axles to get at the tight spots and used a steam cleaner to do the final cleaning (HF has em for under a hundred bucks and it's my new favorite tool).

Finally I painted with Alumi-blast and it turned out great. There's some disagreement as to how much paint (especially silver) contains heat, but I figure it isn't significant and protecting the box from the elements is probably better net-net.

If breaking the whole tranny down, I might consider having it dipped to save myself the greasy mess and my wife complaining about stains on the driveway;)

Posted by: cuddyk Jan 18 2018, 09:45 AM

good catch. I used cleaner. F'in auto correct! Will edit.

Posted by: mepstein Jan 18 2018, 09:54 AM

Steam pressure washer. 5 minutes and done.

Posted by: Perry Kiehl Jan 18 2018, 09:57 AM

Steam cleaner. 210* hot water melts a lot of gunk off. Alternately you can use a pressure washer or take it to a DIY spray car wash. As others have said, tape up the seals and breather, I use aluminum duct tape.

After that foaming engine cleaner with an assortment of scrapers, then brake cleaner.

Then re-tape and media blast with walnut shells.

For a coating I use Dupli-Color spray hi-temp clear

Posted by: Dr Evil Jan 18 2018, 10:01 AM

Pressure washing is a mixed bag. I have seen corrosion from that technique. If you are pulling the stack anyway, just take the case and have it cleaned at a machine shop in a hot tank. If you are pulling the shafts from the intermediate plate, take that and the tail cone, too. Oven cleaner works best with pressure washer. Pre soak. I have someone else do it, I hate cleaning these things. I have found that acetone works wonders for cleaning up the old varnishy, baked on gunk inside and out.

Posted by: Justinp71 Jan 18 2018, 10:23 AM

QUOTE(sdoolin @ Jan 18 2018, 06:04 AM)

Posted by: Bartlett 914 Jan 18 2018, 10:26 AM

QUOTE(cuddyk @ Jan 18 2018, 09:06 AM)

First drain all the gear oil. I got a wood movers dolly and screwed some 2 x 4s across it narrower than the bellhousing (using long wood screws through the bolt holes to secure) so the transmission could stand vertically and be easily rotated to get at all the nooks and crannies.

Remove the speedo drive and block the hole. Tape up the vent well and put a tarp under the dolly/transmission as you work. it's a greasy mess. Like 914sixer said, use a putty knife to get all the thick junk. Then I used 4 cans of brake cleaner to loosen it all up. More expensive than oven cleaner, but it seems to work quicker. Then I removed the stub axles to get at the tight spots and used a steam cleaner to do the final cleaning (HF has em for under a hundred bucks and it's my new favorite tool).

Finally I painted with Alumi-blast and it turned out great. There's some disagreement as to how much paint (especially silver) contains heat, but I figure it isn't significant and protecting the box from the elements is probably better net-net.

If breaking the whole tranny down, I might consider having it dipped to save myself the greasy mess and my wife complaining about stains on the driveway;)

Posted by: 914 7T3 Jan 18 2018, 10:52 AM

Pressure wash, remove internals and then media blast in a tumbler.

No paint or spray coatings of any kind will be required on the finished product. The magnesium pores will close and the case will darken again over time as when it was new.




FWIW Ian's case looks great, but I'm into originality so its all a matter of preference.

Posted by: 914 RZ-1 Jan 18 2018, 10:55 AM

I used this stuff:

https://www.lowes.com/pd/Crown-128-fl-oz-Semi-Paste-Multi-Surface-Paint-Remover/3024382

I brushed it on, let it soak and then pressure-washed the outside. It took me 6 times before I got everything off.

I also chipped off the heavy deposits with a chisel, used a wire brush (hand and on a drill) and got in the nooks and crannies with a pick.

I did mine in a dirt area in my backyard. Then I scooped up the dirty dirt and put it in the trash.

Posted by: Vacca Rabite Jan 18 2018, 11:13 AM

Don't do what I did and soak it in a big metal farm tank sealed up with butyl using kerosene as a cleaning agent.

Oh, the case got clean. But the Kero ate the butyl sealing up the tank and stripped a layer of asphalt down my driveway. It was bad. It was also the day before I was supposed to fly to Cancun for a week. My driveway looked like ass for a few months till the sun bleached the asphalt all the same color again.

Zach

Posted by: NeunEinVier Jan 18 2018, 12:47 PM

Never tried oven cleaner, but Gunk Engine Cleaner stuff works pretty good, especially if you do it on a hot day in the sun. Spray it on and let it sit for 15 minutes then use a stiff plastic brush and a tub of really hot water to loosen and much grime as possible, and hose it off.

Wish there was a good way to catch the oil and grime. Can't be good for the environment rinsing that stuff into the lawn or storm drain. Going to a professional steam rack is probably the most environmentally friendly plan.

Posted by: Mblizzard Jan 18 2018, 02:37 PM

While your choice of clearer/solvent is up to the individual, as others have noted heat works wonders.

I set my trans in front of just a standard electric heater for several hours prior to soaking with a non-toxic citrus based clearer. Let soak about 20-min and used a nylon brush to work it in.

After it is clean, use a fine brass wire wheel brush to do a final clean

The results are astounding.

Posted by: mepstein Jan 18 2018, 02:51 PM

QUOTE(Mblizzard @ Jan 18 2018, 03:37 PM)

Posted by: 914forme Jan 19 2018, 05:55 PM

If you want it to darken a bit quicker.

Eagle One Mag Etch Wheel cleaner. Spray it on good and even, let it sit a few minutes, and spray off with water, dry it in an oven if you can for an hour. If not let them sit in the sun if you can and dry for 24 hours.

After this you can coat with Gibbs, which will darken it a bit more, or shot it with a graphite spray , wipe it down, and it will be nice and dark. And then seal with Gibbs to protect it.

The true way to paint Mag takes a lot of steps.

Clean
Oven Heat - outgas
Steam clean
(optional Weld pitting - then clean again, outgas again)
Prep with Alodine
Use an Acid primer, to get your bite, let cure
2K Prime cure (optional is to fill imperfections, then re 2K prime let cure a long time - 72 hours to a week, unless you can bake them)
Paint cure
Clear cure
Done

Old guy in Cincinnati that did Ferrari and Alpha magnesium wheel restorations taught me this method. Works very well very durable. He is gone now, but not forgotten. And no his name was not Johnny Rotten. https://stevekouracos.com/restoration/tips-and-tricks/aluminum-magnesium-wheel-restoration/ This guy mounts the tires before he does the top and clear coats. Oh course he is dealing with the Alpha and Ferrari crowd, so

Rattle caning VHT on it works, but it will start flacking off over time. I have one in my shop right now that looks like a snake shedding it skin.

Posted by: Tdskip Jan 19 2018, 06:28 PM

Thanks, good discussion

Posted by: NeunEinVier Jan 19 2018, 06:40 PM

QUOTE(Mblizzard @ Jan 18 2018, 03:37 PM)