06 GSXR Clutch Replacement - Stohr

[cjahn]

Howdy!

I think I blew the clutch on my Stohr yesterday. Works ok at low rpm but as soon as I jump car just revs up quickly. Happened very suddenly coming out of a corner. Gears still engage. When powered off in gear car doesn't move. Initally thought it was the diff that blew out but symptoms don't sound like it, and not sure what happens when you blow the diff, but first time I have had this issue.

I think I have to pull the engine based upon limited space. Any suggestions on the procedure and what to replace it with? This is my first try at this and I would prefer not to do it twice!

Any advice would be appreciated.

Thx
Cj

ctjahn@courtneyjahn.com

[David Locke]

Any suggestions on the procedure and what to replace it with? This is my first try at this and I would prefer not to do it twice!

Any advice would be appreciated.

Here is the K5-K6 service manual:
http://www.mediafire.com/file/x9697y...%2529.pdf/file
Disassembly is at 3-18 to 3-21, inspection and service is at 3-44 to 3-47, and reassembly is at 3-93 to 3-98.

Nothing wrong with the stock clutch.

[Farrout48]

I have replaced the GSXR clutch with the engine in the car on my AMAC. It was tight but doable. Even did it at the track once.

Just took a look at my 2006 WF1 with a GSXR in it. There appears to be enough room to get the clutch cover off and replace the clutch with the engine in place. It will be tight and the cover bolts will be difficult to get to. If you can get the cover off, there should be enough room to pull the clutch. I have not had to replace the clutch in my Stohr yet so you know what my advice is worth.

Another concept might be to drop the rear of the floor/diffuser. Not sure if that is easier than pulling the engine or not.

George Dean has told me before that the stock clutch is sufficient, even for one of his built motors. You will need a new clutch cover gasket. Even if you manage to get the old one in one piece, it worth the $ to replace it. I always use a thin layer of the black gasket sealant.

Give Stan Clayton or Critter a call. They would know more about the techniques.

[Racerex1]

I have replaced my clutch twice without removing the engine in my WF-1. Little tight but very doable.

[cjahn]

Prefer to do it in the car. Will have to investigate!

Do the symptoms sound like a clutch? Havent had time to dig into it yet. Just got unloaded and have to shelf the project for a couple weeks.... What else can I do to verify rather than wasting time, potentially causing more issues, or....chasing my tail.

Cj

[ghickman]

Howdy!

I think I blew the clutch on my Stohr yesterday. Works ok at low rpm but as soon as I jump car just revs up quickly. Happened very suddenly coming out of a corner. Gears still engage. When powered off in gear car doesn't move. Initally thought it was the diff that blew out but symptoms don't sound like it, and not sure what happens when you blow the diff, but first time I have had this issue.

I think I have to pull the engine based upon limited space. Any suggestions on the procedure and what to replace it with? This is my first try at this and I would prefer not to do it twice!

Any advice would be appreciated.

Thx
Cj

ctjahn@courtneyjahn.com

It is possible you do have a differential problem, are you using a Taylor diff?

Just to validate that the clutch is actually working do this. Engine off....remove the oil filler cap. Look inside the filler hole. Have someone operate the clutch pedal, you should be able to see the clutch discs being depressed about 4-5mm of movement.


Does your clutch pack still have the slipper clutch functioning?

[cjahn]

It is possible you do have a differential problem, are you using a Taylor diff?

Just to validate that the clutch is actually working do this. Engine off....remove the oil filler cap. Look inside the filler hole. Have someone operate the clutch pedal, you should be able to see the clutch discs being depressed about 4-5mm of movement.


Does your clutch pack still have the slipper clutch functioning?

Thanks Gary! IT should be noted that at low RPM I had no trouble shifting and driving back to the paddock spot. When the car is in gear and off, it doesn't move in gear. I was able to stop, start, and drive with no issues.

I am not sure what the diff make / model is.

CJ

[Farrout48]

Sounds like Clutch plates slipping from your description. Clutch would still disengage and allow gears to be shifted.

Have someone watch chain movement while you attempt to drive off. You could also drag the brakes some. If chain is moving and car not, it is likely the diff. Could also do this up on stands by using the brake to simulate car load.

[Racerex1]

My understanding of testing if the diff is working is to get rear wheels of the ground and make sure the rears will turn in opposite directions. Perhaps others have a better test of diff working?

[cjahn]

My understanding of testing if the diff is working is to get rear wheels of the ground and make sure the rears will turn in opposite directions. Perhaps others have a better test of diff working?

Good question. Mine has never done that....

Cj

[TDI PILOT]

When the car is rolling and you get on the throttle hard, the engine revs up but there is very little actual acceleration of the car right?

If so replace your clutch plates, the fibers and the steel driven plates, don't forget to soak them in your engine oil of choice overnight before installation.

Also check your clutch cable, there should be a little bit (1/4") of slack in the pedal before it starts disengaging the clutch.

-Eric

[cjahn]

Just got back from being out of town for a bit and was looking at the car. Found this bolt in a place which doesn't seem conducive to picking up racetrack trash. Nothing else in the car is ARP or similar in nature. Just wanted to check with folks that this isn't for the driveline somewhere. 98% sure it isn't mine. With my other Stohr (WF1), when I took it apart there wasn't anything like this in the entire car but...

wanted to make sure I wasn't overlooking something.

CJ

[jaltaman]

That looks very familiar, and it's not from the GSX-R engine.

You should check your wheel centers. Note the silicone on the threads. I had those on my (3-piece) wheels.

Someone (if not you) has lost that from a wheel.

At least, that's my bet.

[cjahn]

The wheels I run are single piece. So... Maybe from someone else....

Still havent made the time to determine if it was a clutch failure or diff.

Cj

[Jon Jeffords]

Your description sure sounds like a warn out clutch. As previously mentioned, the stock components will suffice, and should be soaked in oil overnight. Wouldn't hurt to make sure nothing is binding up the clutch controls (cable, pedal). Let me know if you need a hand!

Jon Jeffords

[proutyc]

Do you have the earlier Quaife diff or the Taylor. That bolt looks very similiar to the ones holding my quaife diff together

[cjahn]

All -

I completed more tests today. It should be noted that the failure occurred immediately. It didn't start slipping over time from what I could tell.... Clutch is strong enough to put in first and drive out of my shop (steep incline) and up the driveway. (Also steep). Grips hard enough to kill the engine. Put it in 6th rev'ed it up and dropped the clutch and it died (even on the skinny tires).

So. I took it around the block (quickly). Accelerated quickly. Then slowed. As soon as I get on the power at high r's (Powerband) it lets go.

Jacked it up and put it in gear and one wheel spins forward while the other in reverse. Dropped it on the ground and pushed it forward in gear and feels like a normal car pushing it in gear.

So, based upon your experience.... what are your thoughts?

Still not feeling like its the clutch but may dig into it anyways just for proactive replacement. If it is the quaife who rebuilds? Taylor?

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proutyc -

I have an early quaife verified by a pic and by Stohr. I was wondering if that bolt came out of it? But cant see where it should go or where it should be. Never had one apart but you can see the threads were very stripped.

Thanks everyone!!!
Cj

[Farrout48]

This is a WRD diff from my 2006 WF1. Notice the large nut holding the sprocket carrier on. Taylor uses a circlip If I remember correctly.

[cjahn]

Thanks! After further investigation, all the bolts are loose that hold the carrier sprocket on. This is a different setup than my WF1 had. (I think it had a large special nut). And it appears one of the bolts is missing which explains the bolt found in the earlier post. Long story short, regardless of the clutch situation the entire rear end is coming apart to resolve this and make improvements. Havent decided if I am going rebuild the motor while everything is apart or not. Only has about 5 hours on it since the last rebuild but seems silly to not go through it while I have to take the entire rear apart......

This is a WRD diff from my 2006 WF1. Notice the large nut holding the sprocket carrier on. Taylor uses a circlip If I remember correctly.

[cjahn]

Ok, So after everyone volunteering their opinion it was the clutch I persisted on tearing the rear of the car apart and found all the bolts missing on one side of the Diff. ALL the bolts. Evidence of the other side having one bolt replaced (different style) So before I tear into this which is a bit different than my WF1 I had in the past and replaced the diff bearings....

1. Any suggestions for a FB diff removal?

2. Suggestions on a third party to rebuild it?

Thanks!

Cj

[Stan Clayton]

Courtney, please call tomorrow about the drive flange studs (not to be confused with the sprocket studs). Thanks, Stan

[proutyc]

Courtney, please call tomorrow about the drive flange studs (not to be confused with the sprocket studs). Thanks, Stan

Sorry Dan to jump on this but do you have a stud kit for the early Quaife Stohr Diff?

thanks
Chris

[glenn cooper]

Now would be a perfect time to install a fresh/low hour Gen 5, 2017 Kawasaki ZX10R.
I happen to have one - Minty Fresh - about 3000 miles.

[Stan Clayton]

We are expecting new stud kits any day (recently sold the last set we had), and plan to stock bolt kits as well.

[cjahn]

Anyone ever rebuild a Autotech Quaife diff themselves?

Taylor wont touch it and will only sell me a new 3k unit. Not in the budget. No response from Williams.

Any experience would be great.

Thx
Cj

[proutyc]

Have you contacted Quaife to enquire about the base unit? I have a feeling its a VW one.

I'm about to disassemble mine this off season as I want to remove the ARP bolts and install studs

[john f]

Anyone ever rebuild a Autotech Quaife diff themselves?

Taylor wont touch it and will only sell me a new 3k unit. Not in the budget. No response from Williams.

Any experience would be great.

Thx
Cj

How hard can it be? If somebody made it, you should be able to handle it. Just my $0.02.

john f

[cjahn]

Have you contacted Quaife to enquire about the base unit? I have a feeling its a VW one.

I'm about to disassemble mine this off season as I want to remove the ARP bolts and install studs

I am told from more than one source it was kind of a Quaife ripoff and you will note they dont sell it anymore. You can get the bolts and the sprocket carrier from the orig seller. And Stan at Stohr offers more parts too!

Cj

[cjahn]

How hard can it be? If somebody made it, you should be able to handle it. Just my $0.02.

john f

John you are right. The concept is pretty simple. With the time it takes to pull it I wanted to ensure success using an expert.

We will see if I have the tooling necessary and associated stuff to tackle it myself. I think I have done harder stuff.... I have new studs coming for the sprocket carrier. Already have new bearings (not sure they are the right size yet - had in inventory). And two sets of ARP bolts coming from Stan.

I am a little surprised that no one wanted to do it, less surprised they wanted to sell me a new one. But I understand. And was told it was potentially a weak point in the car and prone to failure and no one wants to be associated with that.

I am also planning on adding an access hole so I can check on the bolts to avoid a future issue. Havent decided how else to avoid future failures. Not sure I want to tie wire 6 bolts above and beyond cleaning and using red locktight if the holes are not too screwed up.

Cj

[john f]

John you are right. The concept is pretty simple. With the time it takes to pull it I wanted to ensure success using an expert.

We will see if I have the tooling necessary and associated stuff to tackle it myself. I think I have done harder stuff.... I have new studs coming for the sprocket carrier. Already have new bearings (not sure they are the right size yet - had in inventory). And two sets of ARP bolts coming from Stan.

I am a little surprised that no one wanted to do it, less surprised they wanted to sell me a new one. But I understand. And was told it was potentially a weak point in the car and prone to failure and no one wants to be associated with that.

I am also planning on adding an access hole so I can check on the bolts to avoid a future issue. Havent decided how else to avoid future failures. Not sure I want to tie wire 6 bolts above and beyond cleaning and using red locktight if the holes are not too screwed up.

Cj

If you need help, or machining, give me a call.

john f

[Stan Clayton]

I'm about to disassemble mine this off season as I want to remove the ARP bolts and install studs

Good luck with that plan. I hope it works well for you, but I am told by a very knowledgeable Quaife diff racing mechanic that studs will not cure the issue with the Autotech Quaife.

I am told from more than one source it was kind of a Quaife ripoff and you will note they dont sell it anymore. You can get the bolts and the sprocket carrier from the orig seller. And Stan at Stohr offers more parts too! Cj

Not a "Quaife ripoff" at all. The Quaife m/c diff was license-built in the USA to Quaife's specs for about 8 years, and when the diff came out it was the best thing going for a m/c powered racing car, bar none. The problem was that the market was too small for a manufacturer to invest heavily in, and eventually they threw in the towel. Furthermore, you guys complaining about them are all racing parts that have seen hard duty for 10-17 years. Are you still running that '03 Yamaha R1 you installed 15 years ago? I thought not, so cut the old Quaife some slack!

And don't forget, Taylor and Williams each had their own issues when they first came out. Our community is lucky in that they both are headed by highly experienced and dedicated engineers whose love for the sport overcame their business sense. They invested in multiple upgrade programs to solve their products' shortcomings, and now we have TWO world-class diffs to choose from.

But back to the Quaife. We do carry the ARP bolt kit and some other common wear parts, but there is no substitute for installing fresh bolts once a year, and torquing them correctly with RED Loctite. And check those bolts' torque every few events!

[proutyc]

Good luck with that plan. I hope it works well for you, but I am told by a very knowledgeable Quaife diff racing mechanic that studs will not cure the issue with the Autotech Quaife.



Not a "Quaife ripoff" at all. The Quaife m/c diff was license-built in the USA to Quaife's specs for about 8 years, and when the diff came out it was the best thing going for a m/c powered racing car, bar none. The problem was that the market was too small for a manufacturer to invest heavily in, and eventually they threw in the towel. Furthermore, you guys complaining about them are all racing parts that have seen hard duty for 10-17 years. Are you still running that '03 Yamaha R1 you installed 15 years ago? I thought not, so cut the old Quaife some slack!

And don't forget, Taylor and Williams each had their own issues when they first came out. Our community is lucky in that they both are headed by highly experienced and dedicated engineers whose love for the sport overcame their business sense. They invested in multiple upgrade programs to solve their products' shortcomings, and now we have TWO world-class diffs to choose from.

But back to the Quaife. We do carry the ARP bolt kit and some other common wear parts, but there is no substitute for installing fresh bolts once a year, and torquing them correctly with RED Loctite. And check those bolts' torque every few events!

That's great information thanks Stan.

[cjahn]

Not a "Quaife ripoff" at all. The Quaife m/c diff was license-built in the USA to Quaife's specs for about 8 years, and when the diff came out it was the best thing going for a m/c powered racing car, bar none. The problem was that the market was too small for a manufacturer to invest heavily in, and eventually they threw in the towel.

Sorry I misinterpreted the situation Stan!

It should be noted that there is evidence of past issues based upon a bolt that was changed out and various other symptoms after digging into it. As indicated many cars are still running them. Its a maintenance item that I just didnt know about because my other MC cars had different diffs that needed less attention.

I am going to build in an access hole into the diffuser so I can have better access if or when needed. And since I havent dug into it yet, I am not sure how it will go!

Stan has provided all the parts he had in stock to help with the issues noted above!

Cj