Hand de-burr and WPC-treat transmission gears

[stuntman]

Hand de-burr: ~18 hours
Transmission gears (including reverse) - check
Input shaft - check
Pinion gear/output shaft - check
Ring gear - check


Check out what i've been doing for the past few weeks. The de-burring process is takes FOREVER, but is more than worth it in the end. WPC treatment is much easier (just send the parts in and a quick turn-around time to get them back). Below is a little writeup I did on my fun little adventure:



Using an air tool and carbide bit, I lightly grinded away all of the sharp edges and stress risers from the sides of the gears, the tips of the gears, and very importantly - the base of the gears. After that, I went through every tooth again with a scotchbright wheel to polish, round off, and smooth out all of the sharp edges. Knocking down these sharp edges/stress risers has been proven to increase the strength and durability of gears, especially since gears are 'torn' at the base of the teeth, de-burring the gears improves the strength of the teeth.

From there, everything from all of the gears, synchros, sliders, needle bearings, shaft bearings, and more were all WPC treated. www.wpctreatment.com

This treatment is used in everything from JGTC, Drag Racing, IRL, Champ Car, Gran-Am, ALMS, off-road truck racing, land-speed record holders and more.

WPC treatment is a similar concept to shot-peening. Whereas shot-peening fires a media at the metal surface, WPC has a much finer media (boulder to grain of sand equivalent), their is also a heat-treating property to WPC treating metal.

Unlike Cryogenically freezing parts which has been known to change the dimensions of the part, WPC does not change the dimensions and increases the strength of a part while not making it brittle, as well as causes the surface of the material to have micro-dimples that retain oil, thus reducing the metal on metal contact - reducing friction, reducing heat, and improving longevity of a part.

Check out their website, or feel free to e-mail me if you have any questions on the WPC or hand de-burring process.

Everything was treated and view the results below:


Stock gear

De-burred gear

Half stock, half de-burred (note the rounding of the edges of the de-burred side, especially at the base of the teeth)

De-burred then WPC treated

Another WPC treated shot

Stock vs. de-burred and WPC treated

De-burred and WPC treated input shaft

De-burred and WPC treated input shaft on the left, stock on the right (note the new WPC treated shaft is a JDM unit while the stock on the right is from a USDM car)

Close up: WPC and de-burred on the left, stock on the right

Pinion gear (de-burred and WPC treated)

Ring gear (de-burred and WPC treated)

Needle bearings WPC treated

 

[john@johnhudakracing]

Nice detail work Billy. Thanks for sharing.

What was the cost for the wpc treatment?

 

[Swift]

I would like to know price and turn around as well. I have this on the top of my to do list for a while now. thanks:biggrin:

 

[Veleno]

What are the benefits of doing this? Reduced wear? Noise?

 

[Mac Attack]

Wow, you have a lot of patience!

What is your power goal? Since I haven't done any engine mods, I haven't researched others drivetrain failures. You must have some ambitious plans to do all that work when others with 700+HP just send their gears to WPC or cryo them and call it a day....

Nice work!


BTW: If others take a die grinder to their gears, just make sure you don't remove excess gear-to-gear contact area. That will actually hurt you!

 

[stuntman]

What are the benefits of doing this? Reduced wear? Noise?

De-burring increases the strength of the gear. rounding off the edges could improve the efficiency of the drivetrain by a few % = more power to the tires, but the gains in power would be insignificant.

De-burring could reduce noise, again at an insignificant level. Production cars are designed with curved gears to prevent the 'whine' and noise of straight cut gears.

WPC treatement also increases the shear strength of the gear. The micro-dimple finish retains oil reducing metal on metal contact. All of this reduces friction, reduces heat, and the treatment would probably give bigger gains in HP to the ground, but again, i'm not claiming it will give an additional 10whp.

I've used WPC treatment in various motor components in some Grand Am cars ive driven. Ok, the team built the motors, had them treated. WPC treatement can be applied to pistons cylinders, cranks, rods, rod bearings, main bearings, cams, cam caps, valves, valve springs, synchros, dog rings, hub sliders, shift forks and rods, gears, oil pumps, bearings (needle and ball), and more. The WPC treated car did have considerable gains in WHP and straightaway speed compared to its sister car that wasn't treated. In spec or rule-governed racing, these gains are very important (every little bit counts). Also many of the drivetrain problems, sheared gears, broken synchros have been reduced or eliminated from the treatment.

I'm also going to treat all said components in my NSX's motor as well.

Wow, you have a lot of patience!

What is your power goal? Since I haven't done any engine mods, I haven't researched others drivetrain failures. You must have some ambitious plans to do all that work when others with 700+HP just send their gears to WPC or cryo them and call it a day....

Nice work!


BTW: If others take a die grinder to their gears, just make sure you don't remove excess gear-to-gear contact area. That will actually hurt you!

Haha, you have no idea how mind-numbing it is.

Due to funds and priority shifts, i'm going to finish my built motor (sleeved, forged pistons, rods, etc...) and hold off the turbo installation until i'm in a financial position where i want to get the turbo. I'm still going to track my car and use it as a test/verification platform (as well as a few other NSXs I have access to) but it's primarily my street car.

** test platform for our company - FX Motorsports Development.

Like you said, don't remove a lot of material, just barely knock down the sharp edges. Its important to round off the edges at the base of the gear because they are torn/sheared at the base (the crucial area that matters), not the surface.

I have the pricing that I'll post soon, but the pricing for 2-3-4 and input shaft will be slightly different than the #'s I have due to mine being the JDM "short" gears. I have to make some measurements of my stock gears and input shaft and send them to WPC to get a quote for those with USDM gear sets.

Turn-around time is VERY quick. All of my gears, synchros, bearings, ring and pinion, etc... were done in a few days.

Again, WPC does not change the dimensions of the gears, nor have the adverse side affects of Cryo treating. I must admit that some well respected Cryo-treating companies/facilities do a great job and are worth it, but it seems that their are a LOT of cryo treating companies out there with little to no background/credibility/history, so be aware and do your homework with anyone you are going to send your parts to.

WPC treatment can be applied after Cryo, shot-peening, or REM-treatments. Their is only one location for WPC treatment in the country - based in Southern California.

E-mail me if you cant wait until then or if you have any further questions.

 

[Mac Attack]

I was just wondering:

There seems to be a lot of slop in our drivetrains. Since I haven't taken apart a transmission, is this where most of it comes from?

If so, then the cryo treatment might be pretty good from the standpoint of a little tighter gear mesh (reduced slop and more gear area contact)?

Dave

 

[stuntman]

I was just wondering:

There seems to be a lot of slop in our drivetrains. Since I haven't taken apart a transmission, is this where most of it comes from?

If so, then the cryo treatment might be pretty good from the standpoint of a little tighter gear mesh (reduced slop and more gear area contact)?

Dave

What do you mean by 'slop'?

Changing the dimensions of a component is rarily a good idea and won't make the gears 'tighter'. Again, reputable companies won't affect the dimensions as much or atall compared to many of the other noname cryo shops.

 

[Mac Attack]

Drivetrain slop, gear lash, whatever you want to call it, many people over the years here have complained about it and wondered if it was "normal" since it is much more readily apparent than in other vehicles. There's a few threads on this where LarryB will chime in and say it's normal for the NSX.

I just found it odd where you said it's known that a cryo treatment changes the dimensions of a part. If we indeed have excess play in the gears because the gear mesh (how loosely/tightly gears contact each other) is overly loose, then it would be interesting if a cryo treatment tends to expand the material or not and lead to a closer or tighter gear mesh. Without knowing whether cryo treatment expands or contracts the metal, this may in fact seem like a good idea since we can't adjust gear mesh inside the transmission. I really don't know and haven't researched it since it is beyond my NSX's capabilities

I don't know if you've ever played around with gear mesh, but loose gears will have slop in them, but have low drag or friction, and have small gear-to-gear contact area (thus limiting to how much power you can transmit).

Conversely, a tight gear mesh will have no slop, but have high drag, and have a larger gear-to-gear contact area. They can handle more power with the expense of added drag.

The other factor with gears power capability and friction is the gear pitch. Generally, the higher (finer) pitch the better, but this is balanced by production cost of course.


I was very interested in your post since I haven't run across anything detailed like this before (thanks again), and it is something I need to start checking into with my twin turbo plans. Also, the slop in my cars drivetrain is kinda embarassing when passengers quickly point it out. It's not nearly as refined as in other cars in it's class, but I have a feeling that's what makes the drivetrain very efficient :wink:

Dave

 

[swerve2007]

cryogenic treatment will never increase the size of the part, only decrease it as metal shrinks.
internal dimensions may grow larger, like inside diameter of the gear etc.
cryogenics only benefits materials that were extensively 'worked'.

 

[Mac Attack]

Thanks, I'm no materials engineer. I'm only (slightly) familiar with annealing.

So, if cryo really only benefits metals that have been "worked," wouldn't it make sense then to cryo AFTER a WPC peening treatment, since their micro-peening process is a form of cold-working for ultimate strength and durability?


Any round-about costs for WPC and cryo treatments on the parts Billy's listed in this thread?

Thanks,

Dave

 

[swerve2007]

most likely cryo process would negate most of the benefit of the 'peening' process as its' purpose is to change the metal's structure.
by 'worked' i meant more extreme processes- wrought, sheared, milled etc.

 

[stuntman]

Thanks, I'm no materials engineer. I'm only (slightly) familiar with annealing.

So, if cryo really only benefits metals that have been "worked," wouldn't it make sense then to cryo AFTER a WPC peening treatment, since their micro-peening process is a form of cold-working for ultimate strength and durability?


Any round-about costs for WPC and cryo treatments on the parts Billy's listed in this thread?

Thanks,

Dave

WPC recommends treating after Cryo, shot peening (not as necessary previous step), de-burring, and REM polishing.

I will put together a list of the various components that I treated for the JDM gearset soon.

 

[ChopsJazz]

Although I'm sure I'm wrong, it seems counter-intuitive that the needle bearings would benefit from the WPC treatment.

Great project.

Needle bearings WPC treated

 

[stuntman]

Although I'm sure I'm wrong, it seems counter-intuitive that the needle bearings would benefit from the WPC treatment.

Great project.

Why's that?

The WPC process creates micro-dimples to the surface of the metal making it harder and stronger, while the dimples also retain oil reducing metal on metal contact = reduced friction and heat.

 

[ChopsJazz]

Why's that?

The WPC process creates micro-dimples to the surface of the metal making it harder and stronger, while the dimples also retain oil reducing metal on metal contact = reduced friction and heat.

See, I told you I was wrong. :wink:

It just seems, at first blush, that a smoother shinier bearing would have less rolling resistance. Like I said, I know I'm wrong...

 

[stuntman]

See, I told you I was wrong. :wink:

It just seems, at first blush, that a smoother shinier bearing would have less rolling resistance. Like I said, I know I'm wrong...

Your logic makes perfect sense so don't worry

The micro dimples are not visible, and you cannot feel them, the finish is duller than a 'polished' surface (as depicted). It becomes more complex in terms of friction and rolling resistance when you put a grease or oil in the equation of the contact between two surfaces.

 

[Mac Attack]

Anyone heard of this?
http://www.procryo.com/RemGears.html

It makes sense to first de-burr them, and then send in for this treatment.


Any rough estimate for WPC, cryo, REM, etc. treatments?

Thanks,
Dave

 

[4mulacar]

This is a really good find, I had forgotten about this process and first saw this in 2000, I belive from a group of visiting engineers from Japan, we were focusing on rotational bending fatigue issues with high speed machining (above 10KRPM to about 40KRPM. This process was tested on a few shafts of our tests on integral spindle motor shafts and increased the life cycle of the shafts tremendously. I never got much information about the process as they were understandedly tight lipped about the process back then. I have been having some gearbox or more specifically ring and pinion issues in my formula car lately and will have to look into this process to see if it may increase my life cycle on these components.

 

[swerve2007]

do it soon and let us know.

 

[4mulacar]

I will, my first concern is will it lower the operating temperature to a significant enough degree where it effects lash of individual components? I have to run enough clearance between the R&P to allow for heat realted growth radially and axially so I'll have to add a sensor to my acquisition unit to monitor. The tough part is what to monitor oil temp, pinion shaft temp, ring temp all of the above? I'll have to put some thought into the desired sensitivity including range of each and find the proper sensors to interface. Currently the system pours oil from a pump directly on the ring and pinion during engine operation driven off of the input shaft. Any ideas are always welcome.

 

[swerve2007]

i doubt the temp will change drastically as for that to occur you would have to have significant increase in oil volume or level of decrease in friction that i do not foresee- then again, thats why i would like you to experiment if you can.

edit; oil temp would be easiest to monitor and technically it would be a good indicator of how things behave.

 

[4mulacar]

i doubt the temp will change drastically as for that to occur you would have to have significant increase in oil volume or level of decrease in friction that i do not foresee- then again, thats why i would like you to experiment if you can.

edit; oil temp would be easiest to monitor and technically it would be a good indicator of how things behave.

Thanks, I made contact with Hewland last night as they are 12 hours ahead of us to discuss my issues with my gearbox. You're thinking is in alignment with the engineers at Hewland and their inputs were the same. This makes my job easier and I will monitor gearbox oil temperature, what did catch me off guard was their insistance that I try different brands of gearoil to determine which brand works best in my application. However after talking to my STLE friend I was reminded that every manufacturer places their own additive package into the oil and this combination of additives are what will make the difference. Same as fuel all from the same refiner until the distributor adds their additive package to make it Shell, Chevron what have you. So again thanks for your thoughts the thermal growth issues I was concerned with are a moot point and the oil temp will give me the indication I need.

 

[Mac Attack]

It sounds like de-burring to reduce the occurence of stress-risers would be the first step like Billy did. Then, a cryo OR WPC treatment for hardening, and finally the REM treatment for friction reduction....

Sounds very time-consuming and expensive! You shouldn't need any oil for lubrication or cooling in your gearbox after all that.

 

[4mulacar]

It sounds like de-burring to reduce the occurence of stress-risers would be the first step like Billy did. Then, a cryo OR WPC treatment for hardening, and finally the REM treatment for friction reduction....

Sounds very time-consuming and expensive! You shouldn't need any oil for lubrication or cooling in your gearbox after all that.

Hewland gearboxes are well prepared and there is very little to deburr especially the gears used for individual ratios and are of much higher quality than webster gears. My issues are with ring and pinion life cycle and no lubrication is instant death no way to wick away the heat!