I was wondering if it would be safe to soda, bead or walnut shell blast my transmission whole if I taped off the vent and perhaps the part lines in the case as to not hit the seals? I have a newly rebuilt transmission I'd like to clean up without tearing back down again.

Kev

Soda would be the only thing I would even consider shooting at a running transmission. But I strongly lean toward it being a bad idea in any case. I've seen first hand how amazingly effective blasting is a sneaking into 'taped off' passages. Before I saw it myself, I didn't believe people who told me tape was never enough.

Tape is never enough.

no.

Kev -

Maybe just some POR Marine Clean away from the openings for oil/grease & crud, possibly corrosion with a fine wire brush or 000/0000 steel or brass wool.

Someone else asked about a protective coating, so maybe use a HT clear on it when done, after full prep of the surface.

Harbor Freight sells a spray bottle that attaches to your air hose. Put in straight Purple Cleaner from the FLAPS and spray away. It eats up crud in a hurry, but BE SURE to protect your eyes, and all painted surfaces, and use the garden hose to rinse everything down in just a few minutes. Then in the honor of 914's , fill the bottle with fresh 20w50 and give it a new clean coating.

Truth be told, the DACO (Dumb Ass Current Owner) that'd be me rattle canned it. Instead of waiting for it to flake and drip off on my garage floor I'd like to undue the damage before it goes back into my car. I did use high temp paint...

Whadda Bonehead!

Try Acetone - apply - wait a few to soften paint - tooth brush in crevices & scrub brush - repeat as necessary!

DAPO &/or DACO did that with paint on my used Fuchs 2L (former), & on body plates & labels on past repaints (both) on mine!

Brake cleaner usually takes off rattle can paint RIGHT NOW!

While I understand the apprehension to condone full soda blasting of a newly rebuilt transmission, can we not agree that 90% of the unit could safely be blasted without risking soda being introduced into the internals? And even if some of it did make it inside, would it cause much damage, given the tiny size of the crystals? If you saw what was clinging to the magnetic drain plug of the tranny I just rebuilt at the Dr's clinic, Soda would not worry you in the least.

I plan on soda blasting mine, coating it with whatever the consensus is on the other current thread and changing the oil twice in the first 2000 miles. If it fails after that, I will make an appointment with Dr. Evil and bring my tranny into his exam room for advice. The flimsy paper that they roll over the table might not absorb all of the oil, but that will be his problem.

I agree that soda is probably safe. I won't be doing it to any of mine, but I'm not against it.

I'd just stick it in and the 914 automatic corrosion prevention system (engine leaks) will do the rest.

....Use as mcmark suggested- brake cleaner- first,... then finish up with pump spray bottle of MAG WHEEL cleaner., watch it foam off the last of the oil and put a shine/original look back to the tranny....got to be careful tho-certain mag wheel cleaners will DARKEN if left on too long.....start at 5 minutes and judge results., flush with lots of water when done...........................M.M.

If you did any prep work at all, it is going to take a long time for the paint to fail.

My old transmission was painted (not by me) and looked great for a long time. Too bad the insides did not look as good as the outsides.

Stripping a working trans is going to cause you more problems then it will solve, IMHO.

Zach

I put my complete trans in my jet wash cabinet. stood it on its bell housing, wrapped teh vent in 5 wraps of electric tape and put a hose clamp over it. 175 deg, rotation, 200 psi and good soap= clean box. no water got in.

soda is an abrasive. does it disolve in oil?

Back the cart up boyz... some of you are saying that you would soda blast carbs... but would not do a tranny that is 99.9% sealed up... riiiiggght.

Personally I see no problem blasting the great majority of the case as soda essentially destroys itself on contact leaving very small particles.

Of course I am no expert but from the research that I have done in the last few weeks I have seen people blast engines, trannys, rear ends etc and have not heard of a "shit I should not have done that" moment.


I dunno

I wouldn't blast assembled carbs and then throw them on a motor either. Apples to apples, my friend.

When I blasted my carbs, the were out of the car and taken apart. I would never blast carbs together, put them back on the engine and expect them to run.

I've personally seen walnut. It gives "perfect", "like new" results.

Also... be VERY careful in the solvent you use on the tranny. Engine degreaser will pit the mag RIGHT NOW. Make sure what you use to get it initially clean will not pit the surface.

YES!!! even oven cleaner will eat it if left on there more than 15-30 min. my parts wash has special sauce to prevent this but must be rinsed off ASAP. I spray them with wd 40 to keep fuz from growing

Umm.. obviously... same as you would to the tranny as well... blast it... clean it up... change fluid... same diff.

Are the gaskets between case part lines vulnerable to blasting?

After blasting or cleaning - you may want to try a clear coat HT engine or exhaust paint like those here from VHT (or another paint/coatings mfgr.) to seal in the Magnesium alloy case material.

http://www.vhtpaint.com/flameproof.html
http://www.vhtpaint.com/engineenamel.html

They also have a magnesium metallic if your case is really badly stained into the metal.

In all cases - proper surface prep is a must to have adherence, & check each paint to make sure it's made to stick to the specific alloy on which your applying.

The circular logic that goes on here sometimes is amazing.

It's ok to use soda on a sealed case becase when you do, it destroys itself on contact into smaller particles.

Did you know sand does the exact same thing. If soda is ok, then so is sand because they do the exact same things.

Heck skip the soda blasting of the outside, just put a handfull of sand into the case and polish the inside too while it runs. It will get smaller....

Why not use dry ice blasting? The particles would sublimate into Co2 gas.

I think the bottom line to this discussion is how does the media get inside? I've heard alot of folks say no way, but haven't heard a good explanation as to how the media gets inside if you take the proper precautions. I qualified my question with at least the common sense to completely cover the vent, where else is it vulnerable. If there was another path, my garage floor would be a huge puddle of tranny fluid.
Hey, I was dumb enough to rattle can it, I'm sure I can muster the stupidity to blast it.

It's pretty simple to explain.

Start yer compressor, pinch yer lips as tight together as you can, place an air nozzle up to yer lips, and pull the trigger.

I guarantee you that no matter how hard you pinch your lips together, at blast pressures the air will blow them apart. If there was sand being propelled by that pressure, your mouth would be full of grit.

Thats what the blast pressure will do to the O-rings and seals in the tranny.

AGAIN...the key is taking the right precautions. Why would I stick the air nozzle in my mouth if I didn't want sand to get in my mouth? Why would I aim the blast media at a rubber seal or O-ring, a vent or case part line? Why would I use sand? I'd love to have someone with practical experience regardless if it's foolish or not respond to this thread.

I'm just curious why you are even asking us?

If you have considered every issue and have all of the right precautions in place, we are wasting our time replying to your questions.

A lot of us have offered opinions that differ from yours, and I've even given you a solution that won't screw anything up and won't require taping.

Let me know how your decision works out for you.

Take care,

Ken

Place your bets, place your bets

You have a high likelihood of epic failure. If that is not a bother to you, proceed at your own peril.

But, what do I know?

Mark and Zach had it correct in the first few posts.

Nevermind...

Kev - the good & the bad about soda & fine walnut media are that the fineness doesn't destroy the rubber & plastic lenses on a car when say you're blasting the body, but it is also fine enough to find its way under pressure into the damnedest places! It just gets by the tiniest of cracks or gaps, as well as being able to make the adhesive on tape fail, etc., etc. This is the bane of fine media blasting!

Any precautions which you take to close off all the gaps, vents, seals, etc. may or may not prevent any from getting inside a mechanical part such as a tranny. If it were a case prior to rebuilding, then you'd blast it, clean it & rebuild a clean case - but this is an operating tranny that we all presume you want to keep that way.

So I guess - proceed at your own peril with medial blasting, or else try some of the other suggested paint removal & clean-up methods here! ... it's up to Bud, because you're writing the checks on your 914!

Blast your transmission already.

NO!
Forget the media you are using for a second...
Where is all the debris that is on the tranny going?

Never use an abrasive on a tranny....its just not sealed well enough to guarantee it wont get in or force something in.

When I clean a case, Its empty.

Rich

Look guys, don't make this a place where someone is afraid of asking questions. Plenty of you have responded with vague, NO NOT HERE type of responses without providing any real reasons. All I've been trying to understand is how the media might contaminate the transmission. I like to try to solve problems which is why I have been persistently asking for the "how".

This has always been an open forum, a guy shouldn't get ridiculed or kicked in the teeth for challenging an opinion that's not backed up with some sort of reasoning.

I do appreciate your feedback, the sarcasm and ridicule; not so much. Apparently it's forbidden to ask for an explanation here so as I said a few posts back, nevermind.

I'm done, no need to provide any additional eyerolls, looks. I'll leave the paint on.

Thanks, and to those I've wasted your time; I do appologize.
Kev

Axle shaft oil seals will let debris in.
Rear speedo will let debris in.
Tranny vent will let debris in
Front main shaft oil seal will let debris in
Shifter console will let debris in.

Rich

I don't think Kevin deserves all of the $hit herein.

Hats off to Rich. It's a good list of probable problem areas.

Kevin,

Maybe I wasn't clear and you took it wrong. You wanted an answer on how blasting would allow the ingress of grit and I tried to give it to you in a graphic fashion.

The reason that I used it is I've done a lot of sandblasting, and the grit riccochets off the surfaces and goes everywhere. To clean up, you shove an air nozzle inside your clothes to remove an amazing amount of sand and particles. Your face is coated in grit around the goggles, and when you use the nozzle to clean the sweat adhered particles from your face and hair, you will find that your lips can't be kept closed. No matter how hard you try. In that case, a water mouth rinse and spit removes most of the grit.

The physics behind spreading your lips and spreading the seals/o-rings with air pressure is exactly the same. That is the point that I was trying to make and it came from blasting experience. And, somehow, the sand even managed to find it's way past my ear plugs and into my ears.

I have also used duct tape to mask and it does a pretty good job resisting the blast media. Sand bounces off, but the tape wears over time.

When the duct tape was peeled up, there were little channels of fine grit rammed under the tape and down any fold in the tape. These folds happen when the flat tape is applied to a non-flat surface. New tacky tape works much better at bouncing sand than a roll of old dried tape.

I hope that helps.

Ken