Modifying o2a/j Clutch fork for high RPM shifting...

[Quintin@USRT]

So since i had a spare one laying around i decided to try strengthening it up some...this included quenching it after each weld.

I wanted to try something different from the typical plate that most people weld on top. I had a friend that bought one modified like that and it contacted the pressure plate.

Anyway without further ado...

[vdubspeed]

very nice. I'm lost though. Why do they need strengthing? What makes them bend? Stiff pressure plates? Why would high RPM shifting weaken them.

[Quintin@USRT]

yes the higher pressure plate pressures cause them to flex and at high rpm centrifugal force forces the fingers out thus putting more stress on the clutch fork. So at high rpms full disengagement is very problematic making shifting a PITA.

[GTijoejoe]

That should make it pretty darn stiff

[Quintin@USRT]

yea but what sucked is there truly isnt chit for clearance in the o2j bellhousing...i had to grind down part of both sides (and all i did was at 1/16th to both sides!) to clear the bolts inside the bellhousing and part of the casting but still should suffice *hopefully* ill get some pics of it later.

[L33t A2]

Very nice.
It would be nice to see a product like this come out for the community that was produced on some CNC machines with some steel billet stock. It wouldn't take more than a day to fab up a vise and a couple jigs rough cut both sides and then set up for the finish cuts.

[Quintin@USRT]

Quote, originally posted by L33t A2 »

Very nice. It would be nice to see a product like this come out for the community that was produced on some CNC machines with some steel billet stock. It wouldn't take more than a day to fab up a vise and a couple jigs rough cut both sides and then set up for the finish cuts.

shhhh

[L33t A2]

i am willing and able to do such work, god forbid we make some profit

[ftwelder]

It would be pretty tough to improve on this with a made from scratch part. I personally would laser cut 4130, stamp or brake form, TIG and heat treat for wear resistance. I would need a 200 pc order. Judging by Quenton's comments, I don't think the envelop shape would allow the required 40% increase in area to use aluminum so CNC would be pretty costly.

How would you do it?

[L33t A2]

I left the machine shop I had been working at to go back and finish my bachelors degree but I didn't forget how to use the machines. Steel alloys suck to work with on the machining centers. The stock part would have to be mapped out on a blue print as well as the clearance inside the bell housing to see where material could be added to promote strength. Carbide end mills and inserts should definitely be used.
Get some .75" steel billet plates or whatever is just thick enough to make the part, you don't want to waste time cleaning off excess material. Skim one side, then flip it over and mount it on a jig/fixture to cut out the rough shape of one side, including the hole in the center. Flip it back over and mount it on another fixture to rough cut and then finish cut that side in one long operation. Mount it on the final fixture to finish cut the first side.
A good programmer could whip this together in a few hours as well as the inverted shapes for making the fixtures from aluminum.

[Quintin@USRT]

i agree CNC'ing a part to exceed the strength of the original would be difficult to achieve...

Below i blacked out where i had to grind the flat bar back down to base metal...

[Agtronic]

I'm not sure I understand the quenching ... this is a mild steel part, which as far as I know, will not harden with quenching. (As opposed to high-carbon steel). That being said, it is definitely stronger with the side reenforcements. I think JUST those would be sufficient, as that is where they tend to break.

[2pt. slo]

Flipside customs has made these for quite some time now.

stock on top reinforced bottom.

Q your welding is improving greatly. looking good man

[Quintin@USRT]

Quote, originally posted by 2pt. slo »

Flipside customs has made these for quite some time now. stock on top reinforced bottom.

yes i know

Quote, originally posted by Quintin@USRT »

I wanted to try something different from the typical plate that most people weld on top. I had a friend that bought one modified like that and it contacted the pressure plate.

Quote, originally posted by 2pt. slo »

Q your welding is improving greatly. looking good man

Thanks!

[Quintin@USRT]

Quote, originally posted by Agtronic »

I'm not sure I understand the quenching ... this is a mild steel part, which as far as I know, will not harden with quenching. (As opposed to high-carbon steel). That being said, it is definitely stronger with the side reenforcements. I think JUST those would be sufficient, as that is where they tend to break.

it can be done with mild...using the right recipe http://lametalsmiths.org/news/robb_gunter.htm

Standard quenching with water though may only just barely harden the surface.

[Passenger Performance]

I don't see why Milling it from 4140 would be an issue. We machine it here all the time, cuts nice.

[GTijoejoe]

Quote, originally posted by Passenger Performance »

I don't see why Milling it from 4140 would be an issue. We machine it here all the time, cuts nice.

I would agree, its not like its carbon carbon.

IMO opinion the proper way to make this part because of clearance inside the bell housing would be to stamp it out of higher strenth steel, and/or be able to increase the thickness or change the geometry slightly (if that is possible judging by clearances)...

This part can be easily backwards engineered, its geometry is not very complicated, although you would need to right kind of equiptment.

[Quintin@USRT]

there's no such thing as easy in the VW world Joe! lol

[Passenger Performance]

Stamping would be ideal, but, I doubt there is enough demand to justify the custom dies. For qts under a few hundred milling them is likely your best bet, we machine 4140 lockout pins for the railway cars here, we mostly machine stainless and I find 4140 more forgiving.

[GTijoejoe]

Quote, originally posted by Quintin@USRT »

there's no such thing as easy in the VW world Joe! lol

Can't argue with that

Quote, originally posted by Passenger Performance »

Stamping would be ideal, but, I doubt there is enough demand to justify the custom dies. For qts under a few hundred milling them is likely your best bet, we machine 4140 lockout pins for the railway cars here, we mostly machine stainless and I find 4140 more forgiving.

I would agree, stamping would be something like +$200/part for very low volume, or something crazy like that. I've had very small brkts made that were +$100/ea. Those though were a series of forming progress and tandem dies.

[boost_addict]

Quote, originally posted by Quintin@USRT »

i agree CNC'ing a part to exceed the strength of the original would be difficult to achieve... Below i blacked out where i had to grind the flat bar back down to base metal...

Working hands.

Fork looks great

[Quintin@USRT]

thanks brah!

[kkkustom]

Wait up here.... is this one of the root causes of the dreaded 02J anything past 4000 rpm grinds like a mofo problem??

I noticed that when I got my SPEC S3 clutch I actually grinded MORE between shifts. Even now with my rebuilt shift hubs i still grind a bit. However my 1 to 2 shift is nice, thanks to big tooth 02A shift hub and syncros!

I too have a left over o2J case, another one of those bad boys in your hand and a TIG welder... I might have to give it a shot!

[whiteriot]

Did the same kind of thing with mine, never really got to try it out but will this spring. Nicely done!

[mechsoldier]

Quote, originally posted by vdubspeed »

very nice. I'm lost though. Why do they need strengthing?

They break even in stock transmissions, I run across a couple a year that are snapped, usually due to the pressure plate becoming more stiff to disengage the clutch as the clutch disk wears. Just did one in a 98 GLX Jetta last week that was snapped.

[MKII16v]

I bent a stock one so far it was touching the pressure plate at idle with only a Sachs power pressure plate. I have been running the Flipside unit for 2 years now and it handles the Clutchnet Red pressure plate great. At $70, its a bargain.

[need_a_VR6]

Quote, originally posted by kkkustom »

Wait up here.... is this one of the root causes of the dreaded 02J anything past 4000 rpm grinds like a mofo problem?? I noticed that when I got my SPEC S3 clutch I actually grinded MORE between shifts. Even now with my rebuilt shift hubs i still grind a bit. However my 1 to 2 shift is nice, thanks to big tooth 02A shift hub and syncros! I too have a left over o2J case, another one of those bad boys in your hand and a TIG welder... I might have to give it a shot!

The clutch fork won't help at all unless yours is bent. Other then full 02a big tooth syncros, etc try *good* gear oil. I've had good luck with Torco.

[diive4sho]

listen to paul...he knows his ****

[TeemuM]

Quote, originally posted by need_a_VR6 »

I've had good luck with Torco.

Have you used RTF or MTF?

http://www.torco-oil.com/produ...ssion

[Quintin@USRT]

i really wish i swapped in o2a sychros while i had it apart swapping r&ps! of course i didnt remember at the time

[pete@integrated]

I looked at machining them. There isn't any room in the bellhousing to increase the cross section where the critical stresses are found, and it would need to be machined in at least 3 or 4 different setups. The worst part is since most steels have roughly the same youngs modulus, you can easily stop them from eventually breaking- use 4140 or 4340- but to make them stiffer so you get all the throw out of the PP, isn't very easy. All you can really do is harden up the steel somewhat which is why Q was quenching.

I think a machined part could be made to be stiffer then stock, especially if the transmission case was ground down to give a bit more room for install, but when i looked at it, it wasn't cost effective.

You certainly don't want to make one out of aluminum regardless of the tensile strength of whatever alloy.

FWIW, these do flex significantly in regular usage even when they aren't "bent"... Like a bit over .060" with a single diaphragm "race" style pressure plate. It may be what causes a lot of these transmissions to drag clutch disks at high rpm. You can't shift a transmission that still has load on it.

PS: Found oooooollld pictures.

I don't think I ever got past "seeing what i could fit in the bellhousing" so that certainly isn't a production ready design by any means. I already see some corners that would need a radius or they would be impossible.


Modified by pete@integrated at 2:52 AM 12-15-2009

[need_a_VR6]

Quote, originally posted by TeemuM »

Have you used RTF or MTF? http://www.torco-oil.com/produ...ssion

RTF is in there now, works a lot better then Redline.

[Agtronic]

Quote, originally posted by Quintin@USRT »

it can be done with mild...using the right recipe http://lametalsmiths.org/news/robb_gunter.htm Standard quenching with water though may only just barely harden the surface.

Recipe or no recipe, the carbon level are so low, I doubt you will be seeing any change in hardness at all. According to wikipedia, quenching carbon steel works for steels containing at least 0.4% carbon, and mild steel has between 0.05 and 0.15% ... Anyways, sorry for bustin' balls, don't mean to nitpick.

edit : Okay, I read the article, and they pitch their theory well, but it just goes against everything I have ever learned about metallurgy.


Modified by Agtronic at 9:55 AM 12-15-2009

[Eganx]

Quote, originally posted by Quintin@USRT »

Standard quenching with water though may only just barely harden the surface.

when I harden anything I quench in used motor oil. the way I understand it, the metal will actually draw carbon out of the oil to harden the surface of the metal. it has worked quite well for me for a while.

[Agtronic]

How are you guys testing for results in hardening?