Clutch help

[ViperGeorge]

I have a 9L extreme with an Nth Moto clutch. When I start the car with the clutch pedal fully depressed and car in 1st or reverse the car moves. The starter is moving the car as though the clutch is not fully disengaged. Clutch still engages at the same spot when driving. Thoughts?

[Steve M]

With the car running and the transmission in first gear, rev it up to 5-6k RPMs. Does the car move at all?

How many miles on it, and when was the last time you put fresh brake fluid through the system (knowing that it is a self-bleeding system, so not sure how well that does getting the nasty stuff out of the slave).

Who did the install? I'm assuming a slave shim was required, but did anyone make note of the clearances?

Unfortunately, this is likely going to be something that may require pulling the transmission to see what's going on in there.

Luckily for you, Nth Moto is a stand-up company...have you reached out to Aaron to get his thoughts? That would be at the top of my to-do list for sure.

[SRT_BluByU]

I seem to recall reading something about one of these aftermarket clutches needing a shim on the slave cyl.. sorry i cant remeber more details if it was this clutchor not.. maybe a lead for you.. hopefully not a wild goose chase.

[Steve M]

I seem to recall reading something about one of these aftermarket clutches needing a shim on the slave cyl.. sorry i cant remeber more details if it was this clutchor not.. maybe a lead for you.. hopefully not a wild goose chase.

The Nth Moto clutch does indeed require a slave cylinder shim, at least for Gen 4 applications. Pretty sure the Gen 5 is the same.

Procedure for measuring is described in detail here: https://driveviper.com/forums/thread...l=1#post373671

[13COBRA]

Do you smell the clutch? Did it slip during One Lap?

[ViperGeorge]

No clutch smell. Maybe 5,000 miles on it. Clutch does not seem to slip. Mark Jorgensen did the install at Woodhouse. Brake fluid was change recently. I don’t know about shims I will ask Mark.

[SRT_BluByU]

Geroge - Out of curiosity why did ya change out the factory clutch? Curious how many miles ya got out of it.. Ive had good luck with the factory unit but am totally bone stock.

[13COBRA]

No clutch smell. Maybe 5,000 miles on it. Clutch does not seem to slip. Mark Jorgensen did the install at Woodhouse. Brake fluid was change recently. I don’t know about shims I will ask Mark.

That's really interesting. Makes me think it might not be the clutch itself and more of a sensor or something? If it was slipping you'd definitely smell it...and with the miles you've put on it in the last week, you'd notice it slipping.

Do the Gen Vs have a clutch sensor that could be going bad? Do you have to press the clutch all the way to the floor and then some to start the car?

[Steve M]

My experience (so far) with the Nth Moto clutch is that it doesn't really slip, even when you try to. I've never smelled anything from this clutch actually, and I've beat on it pretty good over the many years it's been installed in my car.

Next question: does it only do it when the car is hot, or do it also do it from a cold start?

Cooked clutch fluid can wreak havoc on the hydraulics.

[13COBRA]

My experience (so far) with the Nth Moto clutch is that it doesn't really slip, even when you try to. I've never smelled anything from this clutch actually, and I've beat on it pretty good over the many years it's been installed in my car.

Next question: does it only do it when the car is hot, or do it also do it from a cold start?

Cooked clutch fluid can wreak havoc on the hydraulics.

Great point.

First thing I'd do is replace all of the brake fluid.

[ViperGeorge]

Geroge - Out of curiosity why did ya change out the factory clutch? Curious how many miles ya got out of it.. Ive had good luck with the factory unit but am totally bone stock.

I changed to the Nth Moto clutch because I upgraded the engine to 9 liters with 800HP and 790 torque.

[ViperGeorge]

Brake fluid (Motul 600) was changed before One Lap but I suspect the fluid in the slave could be dirty since it shares the brake fluid and there is no separate clutch bleed screw.

I will have to check cold starts. I know it does it when hot.

[Steve M]

Brake fluid (Motul 600) was changed before One Lap but I suspect the fluid in the slave could be dirty since it shares the brake fluid and there is no separate clutch bleed screw.

I will have to check cold starts. I know it does it when hot.

It doesn't take much to cook the fluid, especially if you are running hard for any period of time. And your 9L generates even more heat, so there's that. It just doesn't seem like you can ever insulate the lines well enough to keep the heat in check since they run so close to the engine/exhaust.

I wish you luck in tracking down the source of the problem...it's not fun, but hopefully you can get it figured out and move on to more important things in life.

[ViperGeorge]

Does anyone know how to bleed/flush the clutch?

[13COBRA]

In the Gen Vs, I'm almost positive it all runs through the brakes...so unless Nth Moto has a remote bleeder set up, I'd flush about 3 bottles through the brakes.

[Steve-Indy]

Nick is correct...the stock Gen V has no clutch bleeder. It shares the brake reservoir with the brakes. Supposedly the design of the plumbing automatically rids the clutch hydraulic line of any air.

As you might guess, one can disconnect the line to bleed the system.

George, do you need a few screen shots of this procedure as outlined on the 2014 CD for the the stock system?

[Jack B]

Steve

It is the same for the G5. A shim is an understatement, it is fairly complex machined part, the back side is a press fit on to the boss on the trans.

The unfortunate part of this is, a new slave will probably fix the problem, however, the clutch should also be inspected by NthMoto. As yolu said, the clearance should be carefuly documented.

DSC01833.jpg

The Nth Moto clutch does indeed require a slave cylinder shim, at least for Gen 4 applications. Pretty sure the Gen 5 is the same.

Procedure for measuring is described in detail here: https://driveviper.com/forums/thread...l=1#post373671

[SRT_BluByU]

I changed to the Nth Moto clutch because I upgraded the engine to 9 liters with 800HP and 790 torque.

yes.. that sounds like a logical direction. ha! Thanks George!

[ViperGeorge]

I confirmed with Mark Jorgenson that they did use a slave cylinder shim per Nth Moto instructions. Mark says that Nth Moto gives very detailed instructions on install which they follow. He says they have installed several and to him they all seem to grab high up on pedal release. Mine grabs high too. In fact 3R Racing in Denver commented on this when they did a check out on the car. 3R used to race Vipers.

Jack, why will a new slave cylinder fix this issue?

[Steve M]

Steve

It is the same for the G5. A shim is an understatement, it is fairly complex machined part, the back side is a press fit on to the boss on the trans.

The unfortunate part of this is, a new slave will probably fix the problem, however, the clutch should also be inspected by NthMoto. As yolu said, the clearance should be carefuly documented.

DSC01833.jpg

Interesting...shim in mine looked nothing like what you show.

Mine looked like the top shim in this pic:

https://driveviper.com/forums/thread...l=1#post347210

Just a piece of plate steel with a couple holes.

[ViperGeorge]

I've reached out to Aaron at Nth Moto. Spoke to Josh. Aaron is out until Wednesday. In the mean time I have been pricing slave cylinders in case mine is going. What is the actuator? Is it needed too? I know very little about transmissions and clutches. Josh said to pump the clutch pedal a bunch to bleed it. He said that it would push old fluid out of the slave. I did this but haven't started it yet.

[Jack B]

GEORGE

there are only three components, the clutch, the slave and the fluid. The fluid is an easy change. The slave is cheap. Once you pull the trans, document the slave clearance. This should tell you if the shim is correct or the clearance changed. If the clearance changed the clutch has to come out. Again, the slave is cheap, therefore, error on the safe side, change it.

I confirmed with Mark Jorgenson that they did use a slave cylinder shim per Nth Moto instructions. Mark says that Nth Moto gives very detailed instructions on install which they follow. He says they have installed several and to him they all seem to grab high up on pedal release. Mine grabs high too. In fact 3R Racing in Denver commented on this when they did a check out on the car. 3R used to race Vipers.

Jack, why will a new slave cylinder fix this issue?

[ViperGeorge]

GEORGE

there are only three components, the clutch, the slave and the fluid. The fluid is an easy change. The slave is cheap. Once you pull the trans, document the slave clearance. This should tell you if the shim is correct or the clearance changed. If the clearance changed the clutch has to come out. Again, the slave is cheap, therefore, error on the safe side, change it.

Thanks Jack, what is the actuator? When I called about a slave cylinder the parts guy asked if I also needed the actuator. Does it need to be changed too?

[Jack B]

george

Here is your slave

DSC01836.jpg

[ViperGeorge]

george

Here is your slave

DSC01836.jpg

Thanks Jack but what is the actuator?