Well, the ever clever Scotty B thought that he would be a nice guy and offer his services to my customer base regarding transmission rebuilds. He is offering to paint anyones case that wants it done while I am working on the guts. I have a few questions:

1) Would anyone pay a little more to have there entire tranny case dipped, baked to get rid of oil residue, and powder coated?

2) Would around $100 be a good price for this service?

3) Recommendations for colors?

Scotty will chime in here soon enough to answer questions as well.

would powder coating possibly warp the case?

It might make the metal weaker.. right?

100 sounds right for nice powder coating..

Super gloss black
White
Orange
Silver
Grey
Red
Super gloss CLEAR
And gold for bling bling.

If the trani can hold up to it.. I'd have mine powdered..

you should offer flat black too.

if i were gonna do mine it would be flat black.

-jim

400 degrees should do nothing to the case. Why do you think the metal would be weakened?

Colors that Scott is thinking we will go with are black and a clear coated silver that looks like brushed metal.

Sounds good but I'd check into how much sustained heat a Magnesium case can withstand before getting weird.

Mike... I'll be throwing as much tq and abuse (400lbs of tq +10.5in slicks...) to the trani as I can... I dont want to weaken it in any way....

lol

Why would you want to powder coat a trans? Why trap that heat inside? I suppose you could run an external cooler or something to combat the heat.

The mag case is prone to corrosion. i have painted mine. i have run across several bare cases with white fuzzy corrosion on the outside.
i don't know if the factory did any coating or not, maybe an anodizing process?

mag. is pretty reactive. Road salts and powerful cleaners can hurt them. \

A thin coating would be best for heat rejection. A high gloss is worst for heat. don't know how much it matter, but I'd keep it thin as possible unless you know otherwise.

Mine is painted light grey, looks good, no corrosion after ten years. i used rustoleum spray can paint.

Cleaning is a bitch, as the case is somewhat porsis, so it traps oil easy.

early VW engine cases are mag, there might be experience with powder coating on them. it may or maynot be the same alloy. not all mag is the same, but it might be close.

it is common VW knowledge to only paint the engine cases with a thin flat black for best heat rejection. Gene Berg wrote some stuff up on this. See if VW guys have good luck with powder coating engine cases, just be advised that thin, flat black paint is the recommend choice. Of course, engine have bigger heat issues than trannies.

hmm id like to see what this looks like. any pictures.?

I powdercoated my case. The case did change shape a little, but I doubt it is enough to matter. The bearing races in the case went from "snug" to "mega tight" (this is a good thing) and the material where the studs are mounted for the side cover bulged out at each stud just enough for the side cover to not fit without some filing. The intermediate plate also required some extra tapping to get it on that it didn't require before. This was with my old oven control that turned out to fluctuate between 425 and 500 degrees instead of holding at 450 like I thought it would. The above might not happen with a proper oven controller (like I have now).

They powder coat alloy rims which stay true. Make a jig plate for both ends

( cheep alum plate with a few holes) to keep its shape if there is a concern.

Saw one painted close to the cars color(might have been the same) with

the fins sanded to metal, looked great.

From Bondos reply, i'd be very worried about the heat process ont eh tranny case. beraing races tightening up, and bulging are not good on a tranny. if the wrong diminsins change, you can be in real trouble with the gears (ring and pinion set up come to mind0 you may end up having to reset up the R and P gears for propper running. This is probably a bad omen for powder coating. evidently diminsions did change.

heating and cooling would have to be very carefully controls, and probably done very very slowley to prevent warping. inclusions int eh casting may burt open.

ii owuld go with paint. Mine still looks good after a decad of use. i degreased it, then used solvent as a final clean, dried it with flood lights for a couple days (not all that hot) then rattle canned rustoleum primer and top coat, keeping it thin.
this is less expensive ($10 in paint) and I have no worries with heat warping. i did not even need to dissasemble the tranny when i did this. this gave me the corrosion protection i wanted, and looks good.

poweder coating i think is too expensive,a dn the above posted problems with warping and bulging are not worth it. if you do it, you might end up buying the customer a new tranny. i'd definatly experiment on several cases of different conditions (some are more pittied from corrosion to start with,a dn may not survive as well as a better case. I have seen cases with corrosion spalling all over them. run some tests and take before/after measurements on several location, check flatness of surfaces, etc... also refer to the Mag cengine case VW guys as there experience check with the experts, as there are many you might have done it, and don't understand the pitfall they have run into.

proceed with caution before you market them is my adivce, run test shots, and do the homework. My opinio of powder coating of cases is it is a nice show car trailer queen idea, but in actual use it may not be that good an idea, until proven otherwise. good paint is a my choice.

poweder coating wheels may not be as much an issue, they don't have the tolerance concerns of the tranny case. I rather have painted wheels, easier to repair with touch up paint for minor curb rash.

basic black....

I looked all over my computer for that pic yesterday... couldn't find it!

O.K. guys here I be. As for the csae being damaged, powder coating is done at a sustained 400-425 degrees. 500 is to high and I'm not surprised your case moved, between the heat and most likely a cramped oven with poor air circulation.I do have a VW case I will be experimenting with in the next 2 weeks and as the Doc and I discussed I am concerned about getting all of the contaminants OUT of the case and as part of the process would actually bake the case uncoated to coax any remaining oils out. We always bake cast materials whether they be aluminum or steel prior to coating for that very reason. Another concern of mine is the condition of the cases I would be receiving. I expect them all to need a cleaning but how much of a cleaning will it be????Time will tell if this happens. As for the colors, the sky is the limit. There will be a set price for standard single coating colors but things like Chrome, the silver Doc spoke of and candies have to have a coat of clear which means more materials and more baking time so there would obviously be a bit more added to the price of those. I personally think black (in any gloss) and the silver will be the best looking but I will also try cleraing over the clean case with no color added to see how that looks. If any of you nut jobs wanted to polish the ribs and color the recesses..........we MIGHT could talk about that to $$$$$$$

I'm a little confused also as to what kind of temps you guys think your case produces under normal conditions. Has anyone even taken a long trip and used an IR thermometer right on the case and away from the exhaust to have any idea of how hot a tranny gets Please don't misconstrue me as being a Krusty a-hole I ask this seriously. I have no idea what normal operating temp is but can't believe it is very high and would be harmed by a thin coat of powder . I have also seen many trannies CAKED in oil, one of which was actually over the tops of the ribs, ther's no way powder could hold in near that much heat

Doc and I are trying to get a feel for interest right now and as I stated before I will be trying this out on an old swing axle bug tranny before I attempt an expensive, specialized, highly desireable, gold plated ( gold plated huh?) Porsche trans

well if i'm gunna drop >$1000 on a rebuild, whats another $100 to make it look good, very clean and add some protection against the elements...its just money right?

WHY?

I think anything that is going to make our cars look better is O.K.
Powder coating is the cats Ass ,I have done 4 wheel cyls. all my engine tin and 4 Mahlie rims. Literally spray with water to clean,nothin sticks to it .
Lets see i wonder how much to powder coat the whole car??????????? HUMMMMM Dave

WHY NOT?

HA! Took ya long enough to object

I really like the way the F-ers are synchronized

Twerling, twerling, mocking, mocking

This sounds good, but I wouldn't want to lose points at the next concourse

Put me in for flat black

Ha! You guys are funny. Especially Andrew. "Weaken the case" HA!


Anyway... All insecurities aside, there is one pro and on con.

+ The case looks nice
- Heat retainment

And whoever asked about how much heat the tranny makes... We read 375 right at the diff after a race in a 911.

EDIT: And VW nor Porsche ever applied any coating to their engines for fear of heat retainment.

And I think the tranny would look *best* if all the high points were left shiny. Or even painted a different color, like neon green. Remember battlezone?

powder coated sparkel silver

Well, it's just my opinion but I would never heat a precision magnesium part to 400+ degrees for looks only. Why run the risk of warpage? That's WAY more heat than they run on the road. I would not heat a precision part to more than it sees in normal service. Just my policy though.

I coated mine with a light coat of clear engine enamel to seal the pits and corrosion and to make it easier to clean.



Click to view attachment

Your worrying about all of 90lbs of tq on a trani that holds 300lbs of tq..

Im struggling to detune a 500lb tq engine to 400lbs of tq, and retain the drivablity, powerband, and higher rpms im looking for.. with true slicks, on the track.. on a trani that cant take more than 400lbs of tq.. on the street. on stock tires.

Shut up. I have the right to worry about the little things.


heres a quote.

"The case did change shape a little, but I doubt it is enough to matter. The bearing races in the case went from "snug" to "mega tight" (this is a good thing) and the material where the studs are mounted for the side cover bulged out at each stud just enough for the side cover to not fit without some filing"

Well there sure is a lot of supposition going on. Looks like it is time for the transmission myth busters to take action. Basically, Bondo's oven was not of the quality that we will use so the data point is suggestive, but not definitive. If what he experienced were to happen in any way in a set up that Scott would use then we would not do it. Yes, we have cases to experiment with. Yes, we will make sure that no customers tranny gets warped. Everyone has the right to expect that their tranny not get warped when it is in for service
I trust Scotty's opinion when it comes to the feasability of this endeavor because he is a professional and shares my views on quality of service and product.

Other myths to be or that have been busted:

"Heating your case can cause a class delta fire because Mg burns!" -- peniding further investigation where I will take a piece of case and try, very hard, to lite it up under cercumstances that would not normally exist during heating a case to remove a plug.

"Easy-Off oven cleaner will etch your case and ruin it!" -- tested, not entirely true! I soaked an intermediate plate for over 24hrs in Easy-Off. Whilke it did etch the metal ever so slightly (mind you this is WAYYYYY longer than you would be exposing your tranny to for cleaning) the amount would not be significant unless you treated the mating surfaces in such a way.

"Powder coating will warp your case!" --- Pending, stay tuned.

"Heating your case can cause a class delta fire because Mg burns!"
Actually, while magnesium does burn, it will not burn in a large chunk like the case of a tranny
It is incredibly difficult to set a chunk of magnesium on fire and should not be a real issue in this situation
The only real concern with magnesium is in its powdered form
But, I doubt any of these cases will be powedered
Just my $.02

Mike.. I tried.. the magnesium isnt pure enough.... Sigh..

heheheh

PS.. I would LOVE to paint my trani, but you need some good before and after numbers of the tolerances before I say "do it" on my trani.

Andrew

I think thats a great idea. 100 bucks for the powdercoat job is a fair price.
If you don't know anything about powdercoating. 400 to 425 F for 20 to 25 min will not hurt your tranny housing. As for holding in extra heat- again, not hot enough to make a damaging difference. This will also not create any damage to the metal. When powdercoating any pores type casting you need to make sure its as clean as possible but i know the guys have that covered.

There alot of great colors available and I did mine in Dupont Teflon green- "weird", I know but I had it left over from another job.

Great idea....
KP

Looks like a mix of opinions, one guys says his case did change, another says no problem (but didn't say he tried it) it may come down to how even the heat is, a factor of the oven design, and temp ramp rates. metal can be warped by uneven heating that is a well know fact (the concept of heat shrinking body panels for example) control of the heat will be important. It is well established that the trany case diminsions are important for a long life, and smooth running tranny.
so if the tranny case can make it thru the process is the first question. the next question is if it is desireable from a heat standpoint.

there is info on paint,a dn engine cases, and cylinder outer surfaces. generally a thin flat black is considered best. this radiates heat best, and the thin coat does not over insulate.

question to askt eh powder coater person is how thick is the finished film? How does that compare to thin coat of paint?

I had a paper on cylinder walls. VW guy did an engineering paper on heat transfer with different paint coatings (and bare, and greasy dirty) using thermal couples, to measure heat loss rate. bare and thin flat black won as the best heat rejecting coatings.

then you need to ask, does it matter in your application? (ie street driven stock car, verses high HP track car)

once these are answered, it will be an easy choice!

it is good that we proceed with caution,a nd wait until the facts are known. i am sure the guys proposing this coating service will cover this, it appears they are willing to run tests, this is a good sign. i like responsible vendors. Amyone willing to take the time to reseach this, and run tests is probably going to make sure it is a quality product.

keep us all informed on you results, this is very interesting.

thanks

the company how did mine sad they do it all the time with no problems,put the trans together w/o the internals ,2 screws on the tailcone and 2 screws on the sideplate,my cost was $150.00 but it is powder coated two times ,silver and clear on top

That makes a lot of sense, Thomas. The price is right too. Thanks for the input.

Just wanted to let you guys know I haven't forgotten about this. I have just been swamped between werk and trying to repair my parents roof. I have a donor tranny (914) that I tore down this after noon and will try to get it cleaned up by mid-next week. I got a new box of powder so that is ready and will TRY to get this thing coated after Thanksgiving! BTW Dr. you may have another tranny rebuild after the first of the year. You've got PM !!

I have my doubts that the cure cycle (approx 400 deg. F for 30 minutes) will really warp the transmission much. (but you would have to do some very precise measuring to know for sure)

I know of a manufacturer of Stern Drives that are routinely E-coated AND powder coated (apparently with little or no ill effects). They do take into account the mil thickness of the e-coat for bearing races, but apparently the bearing bores stay true enough in their aluminum castings.

I would still be fearing heat retention. I think a very thin coating (perhaps black or silver) may be a better option if you must paint the trans for some reason.


just my $0.02