RPS Twin Plate Carbon-Carbon Clutch Experiances

[Erron Spalsbury]

At what power levels are you guys recommending the end case brace?

[MR2]

I wish I had a hoist...life would be sooooo cruisy.(but I have no room for one in my single car garage)

instead I lifted it with two jacks and held it with one of them while snuggling it in fitted like a glove will test it tonight

[Mitsuman03]

At what power levels are you guys recommending the end case brace?

I wouldn't place it at a power level, rather your intentions of usage. I have not done this upgrade yet, although i may actually go the billet route.

[MR2]

yeah, pretty much only needed for dragging. I seem to remember Matt said he created his one when he blew out his end case bouncing off the rev limiter in gear.

[MR2]

Back to being on topic:

over the last two days, I pulled the GB re-lubed the shafts and re-installed the clutch. I don't know why but everything this time was perfect, easy to get the GB back up, easy to get the gb to slide into the clutch, easy to bolt back up, and low and behold at the end of it the clutch is now perfect.

of all rofl's, my second gear syncro is now gone AGAIN...guess I'll get it replaced the next time the box is out...AGAIN.

anyway the clutch is still a little shuddery if you try to do a reallly smooth engagement however when you learn(or when I) to match the Accellerator with letting it out fast (as opposed to being a pansy) it's fine.

[J. Fast]

What you forgot to mention, and what they did not evaluate is that these transmission had no intentions to put down and handle as much power as some do today, and like any other metal that's abused over and over again after a period of long time, they weaken. For there time, they where slightly over engineered part, and where strengthened to the best of there ability..(hence the 3 ribs that seem to "strengthen" the walls of the bell housing.....hmm.wonder why they put those there? When you have a force of uncommon strength being applied at such a speed, when the gears mesh together in abrupt force, the unit as a whole will flex, causing them to push apart from each other and "mis aligning' the teeth...well..if there's no room for these errors being that the tolerance is oh so tight, i guess the only way is in the "away" direction..causing them to push apart.....well..guess what there going to push into?

I thought I'd take the time to shoot down the hype on the billet end cover and so forth. Again, the weakness in our transmissions is in the bearing design. It has nothing to do with the type of material the transmission is composed of or it being "weak". It has to do with maint and setting it up in spec. Want to make big power? You're going to increase the gearmesh excitation freq's and compress the end bearings. Everytime you launch it the end bearing shim heights/ preleoads become a maint item and regardless of wether or not you have a billet end case the preloads and gearmesh patterns will need to be checked just like a Nascar performance engine is stripped and rebuilt every time it's ran.

It has been proven that all meshing gears generate harmonics and vibrations. In our case we have a helical gear design and the gearmesh vibrates. The vibration should not be confused with transmission whine from the style of tooth engagement but an excitation from the gear mesh. I will state the simple findings and you can run with your idea or take the answer in the transmission design failure report I have studied along with a number of three dimensional gear vibration analysis, multi-stage gear engagement reports, Houjoh's gear-vibration study and findings models, Kato's noise defraction and reflection studes on drivetrain harmonics, and my personal experience in rebuilding these drivetrains. I am quite familiar with DSM and 3/S drivetrains and have performed a number of complete disassembly, reassembly, regear, and so forth.

IMO the design flaw has nothing to do with the strength of the bellhousing and end cover. It has to do with the compressability of the end bearings. OEM end bearings will compress long before the end cover or bellhousing will separate (explode) from helical mesh tilting. It is aproven scientific fact that torque ripple in motors, improper bearing race shim position, and fluctuations in tooth stiffness cause excitation during gear meshing. This mesh excitiation propigates from the gearshafts to the bearings (where it is converted into a bearing force), excites the gearbox, and generates gear-vibration noise which is radiated from the surface of the gearbox. The "tuning fork" vibration traveling down the input, intermediate, and output shafts sends endstress to the bearing races and changes the preload which alters the gearmesh which in turn amplifys the gearmesh vibration. The end result is the gear teeth bind and the vibration increases and eventually the force from improper mesh blows the housing or shears the gear teeth and the transmission binds on itself and blows.

Of course we are all entitled to our opinions. I feel my opinion is well researched and founded. Here is a screen shot of some of my research.

[CoopKill]

I thought I'd take the time to shoot down the hype on the billet end cover and so forth. Again, the weakness in our transmissions is in the bearing design. It has nothing to do with the type of material the transmission is composed of or it being "weak". It has to do with maint and setting it up in spec. Want to make big power? You're going to increase the gearmesh excitation freq's and compress the end bearings. Everytime you launch it the end bearing shim heights/ preleoads become a maint item and regardless of wether or not you have a billet end case the preloads and gearmesh patterns will need to be checked just like a Nascar performance engine is stripped and rebuilt every time it's ran.

It has been proven that all meshing gears generate harmonics and vibrations. In our case we have a helical gear design and the gearmesh vibrates. The vibration should not be confused with transmission whine from the style of tooth engagement but an excitation from the gear mesh. I will state the simple findings and you can run with your idea or take the answer in the transmission design failure report I have studied along with a number of three dimensional gear vibration analysis, multi-stage gear engagement reports, Houjoh's gear-vibration study and findings models, Kato's noise defraction and reflection studes on drivetrain harmonics, and my personal experience in rebuilding these drivetrains. I am quite familiar with DSM and 3/S drivetrains and have performed a number of complete disassembly, reassembly, regear, and so forth.

IMO the design flaw has nothing to do with the strength of the bellhousing and end cover. It has to do with the compressability of the end bearings. OEM end bearings will compress long before the end cover or bellhousing will separate (explode) from helical mesh tilting. It is aproven scientific fact that torque ripple in motors, improper bearing race shim position, and fluctuations in tooth stiffness cause excitation during gear meshing. This mesh excitiation propigates from the gearshafts to the bearings (where it is converted into a bearing force), excites the gearbox, and generates gear-vibration noise which is radiated from the surface of the gearbox. The "tuning fork" vibration traveling down the input, intermediate, and output shafts sends endstress to the bearing races and changes the preload which alters the gearmesh which in turn amplifys the gearmesh vibration. The end result is the gear teeth bind and the vibration increases and eventually the force from improper mesh blows the housing or shears the gear teeth and the transmission binds on itself and blows.

Of course we are all entitled to our opinions. I feel my opinion is well researched and founded. Here is a screen shot of some of my research.

So, what then would be a solution?

[MR2]

Even with all that information I still don't see how you can say the Endcase does nothing, you've mentioned that the end bearings can be compressed...by how much? then what? since we can't actually adjust each of our gears to a double helix and since every gearbox practically in existance has the same design (excluding straight cut due to noise) it seems to me that the end case is a reasonable solution to the problem and while you think the problem should not exist it obviously has happened to a few people (see matt's threads)

at the very least it's shiny

[J. Fast]

When you start to develop power over say 800 to the wheels routinely check your gearmesh patterns, backlash, and preloads for all drivetrain components. Maintain them like a racecar, because effectively that's what you own with that kind of power. Service it every time you launch the piss out of it. The original car owner on our CC team owns a 1000+hp DSM. For longer than I've owned my car he's ran a stock trans, and rebuilds it 5-10 times a season.

When you make big power inherent maint comes along with it if you drive your car for the purpose it was built for... To put down power. You could choose to drive it like a pussy and show it off at shows and the first time you are tested it will break because you overlooked some big power maint item because it was built for show and not maintained for go. Most of teh folks I run with are constantly servicing and working on their respective cars. Nearly everytime we comeback from the track we're taking something apart and maint something else, and our cars continue to develop more an more power. The more power they make the more shit we have to take apart to doublecheck everything. Our maint has increased but nothing is breaking. So it all comes down to maint and preperation.

A simple test would be asking anyone making over 600hp how often they nut and bolt their car. Myself and anyone with common sense should do it every time the car is driven. You'd be surprised how much everything shifts and moves with that kind of power.

[MaxClass]

Check out this excellent video on properly adjusting your clutch. I learned a lot I did not know regarding adjusting the pedal linkage and using the slave cylinder to check for the exact settings on the pedal adjustments. Well worth the read.

Could also be the problems with the clutch not fully disengaging as it should. Every one would do well to watch this one.

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Good Luck.