Speed Shifting issues

[rzaenglein]

I have a 05 GT making 375rwhp. Car has big issues with very fast shifts. primarily going into second and a real big issue with 4th. 3rd hardly ever gives an issue. Under normal driving car has no issues except when the car is first started. When the tranny is cold the first few shifts into 2nd and 3rd have to be very slow or it will give a slight grind. It also feels when i pump my pedal a little bit it stiffens up a bit.

The drivetrain setup is a TR6060 with a mgw shifter, spec stage 2+ with aluminum flywheel and pressure plate, new factory slave cylinder, new master cylinder, ford racing clutch line.

The transmission is a level 6 done by rpm transmissions out of muncie indiana with maybe 2000 miles on it. I noticed when I put the car in first with the clutch to the floor when i revved it to 5500 and above it made the car move.

I know the clutch not completely releasing is at least some of my issue if not all of it. I think there is air in the system that I cannot get out. I have pumped the pedal for ever and vacuum bled it numerous times. It holds good vacuum.

Has anyone out there ever taped into there slave and threaded a bleeder valve into it? Is there any aftermarket slave that has a bleeder? Anyone had to shim there slave? Any other ideas???

 

[19COBRA93]

It sounds like you need a shim behind the slave. The Centerforce DFX clutch requires one for example.

These hydro systems bleed very easily, so if you're still having disengagement issues, I would say it's very likely it's something other than air in the system.

 

[skwerl]

Can anybody provide a little more detail on this shim, where to get them, how to measure to see if you need one, etc. I think mine needs to be shimmed as well but I don't know where to start and neither does my mechanic.

 

[19COBRA93]

Can anybody provide a little more detail on this shim, where to get them, how to measure to see if you need one, etc. I think mine needs to be shimmed as well but I don't know where to start and neither does my mechanic.

This is the shim that comes in the DFX kit. The kit requires the 05-09 GT500, or 05-10 GT slave cylinder:

.

 

[skwerl]

I'm not familiar with a 'DFX kit'. Where can I buy the shim?

 

[BruceH]

A ls shim will work. I had a pos centerforce clutch at one time and have a ram ls shim. Send me a pm if you want it.

 

[19COBRA93]

I'm not familiar with a 'DFX kit'. Where can I buy the shim?

Centerforce DFX.

http://www.summitracing.com/parts/ctf-01611679/media/images/make/ford/model/mustang

I would think you can get the shim through Centerforce, or someone who is a distributor for Centerforce, or possibly have one made. Or get the one from Bruce.

 

[ctt326]

My spec 3 came with a shim, so instead if trying a different brand give spec a call.

 

[michael.konor]

My spec 3 came with a shim, so instead if trying a different brand give spec a call.

What thickness shim came with your SPEC 3? Didn't get one with mine a few years back. Made my own, but curious...

 

[Department Of Boost]

I have a 05 GT making 375rwhp. Car has big issues with very fast shifts. primarily going into second and a real big issue with 4th. 3rd hardly ever gives an issue. Under normal driving car has no issues except when the car is first started. When the tranny is cold the first few shifts into 2nd and 3rd have to be very slow or it will give a slight grind. It also feels when i pump my pedal a little bit it stiffens up a bit.

The drivetrain setup is a TR6060 with a mgw shifter, spec stage 2+ with aluminum flywheel and pressure plate, new factory slave cylinder, new master cylinder, ford racing clutch line.

The transmission is a level 6 done by rpm transmissions out of muncie indiana with maybe 2000 miles on it. I noticed when I put the car in first with the clutch to the floor when i revved it to 5500 and above it made the car move.

I know the clutch not completely releasing is at least some of my issue if not all of it. I think there is air in the system that I cannot get out. I have pumped the pedal for ever and vacuum bled it numerous times. It holds good vacuum.

Has anyone out there ever taped into there slave and threaded a bleeder valve into it? Is there any aftermarket slave that has a bleeder? Anyone had to shim there slave? Any other ideas???

What are you running for engine/trans mounts? If the motor/trans twists under power it binds the shift linkage and causes all sorts of issues.

I have a custom bleeder setup on my 2007's slave. Works great. A bit of a PITA to make though.

 

[one eyed willy]

Can anybody provide a little more detail on this shim, where to get them, how to measure to see if you need one, etc. I think mine needs to be shimmed as well but I don't know where to start and neither does my mechanic.

http://www.ramclutches.com/Instructions/RAM Hyd Setup.htm

Go to the bottom of this page.....you can order the shims from summit racing, or it's pretty easy to make your own with a flat piece of metal.

http://www.summitracing.com/search/...-line/ram-slave-cylinder-spacers?autoview=SKU

I happen to have one I don't need if anyone needs it....

 

[rzaenglein]

I have a BMR tublar K in the car with polyurethane engine mounts. tranny mount is the stock rubber bushing. I contacted spec and they explained to me that there clutch kits are designed to not need shimming, but from what I'm seeing it sounds like some of you guys have shimmed your spec cluthches with success. I'm very curious about how you made a custom bleeder. Did you feel that it helpful? And got more air out than the vacuum bleed procedure?

 

[rzaenglein]

Also does anyone have a certain clutch combo that they absolutely love and are confident that it is disengaging 100%

 

[AutoXRacer]

Also does anyone have a certain clutch combo that they absolutely love and are confident that it is disengaging 100%

I absolutely love my McLeod RXT...
You just have to make sure it is speced by McLeod (clutch assembly and flywheel).
No shim required.

 

[skwerl]

I have a couple more questions-
1) How exactly do you measure for the shim thickness? What are the specs?

2) I discussed this with my mechanic and he said to get online and see if I could find an adjustable clutch pedal actuating rod. He said it would accomplish the exact same thing without having to pull the transmission. Anybody ever heard of such an animal for our cars?

 

[rzaenglein]

I absolutely love my McLeod RXT...
You just have to make sure it is speced by McLeod (clutch assembly and flywheel).
No shim required.

I know people love those clutches for sn95 cars. I have driven an 04 cobra with a rst and i loved it. May go that way when my spec is finished.

 

[rzaenglein]

I have a couple more questions-
1) How exactly do you measure for the shim thickness? What are the specs?

2) I discussed this with my mechanic and he said to get online and see if I could find an adjustable clutch pedal actuating rod. He said it would accomplish the exact same thing without having to pull the transmission. Anybody ever heard of such an animal for our cars?

For your first question I cant give a good answer, I tried the ram adjustable slave and tried to shim it correctly. I could never get it right and it had leaking issues, I also tried the mccloud adjustable slave and could never get it shimmed correctly either. I don't remember the measuring procedure though. Never have tried shimming with the factory slave.

For your second question I don't believe that is possible either because the master cylinder is on the inside of the car and is directly connected to the clutch pedal if I remember correctly. Been a while since I replaced mine. Unless you could somehow disassemble the master cylinder and fabricate an adjustable rod and put it back together.

 

[AutoXRacer]

I have a couple more questions-
1) How exactly do you measure for the shim thickness? What are the specs?

2) I discussed this with my mechanic and he said to get online and see if I could find an adjustable clutch pedal actuating rod. He said it would accomplish the exact same thing without having to pull the transmission. Anybody ever heard of such an animal for our cars?

1)You don't measure the shim. You have to measure the stock clutch finger height, then measure your new setup. The difference is compensated by a shim who's thickness is the difference.

2) Not possible. As the post above, the master cylinder and pedal are all one assembly and if you could mod an adjustable rod, it would just damage the master and slave. The slave already fully extends with the stock master cylinder...no need to extend it any further.

Who are you using at a mechanic? You are making me worried... lol

 

[AutoXRacer]

I know people love those clutches for sn95 cars. I have driven an 04 cobra with a rst and i loved it. May go that way when my spec is finished.

Make sure its the RXT...don't waste your time with the RST.

 

[skwerl]

1)You don't measure the shim. You have to measure the stock clutch finger height, then measure your new setup. The difference is compensated by a shim who's thickness is the difference.

OK, I'm beginning to extract bits and pieces of relevant information. Sorry if I keep asking the same thing over and over, but I'm trying to determine the exact procedure never having done it before. Giving me one step out of 5 doesn't help me much, it just makes me ask 4 more times to discover the other steps.

So far I am under the impression I measure the height of the clutch finger height (measuring off the bell housing mounting surface I assume) and then I measure the distance from the tob to the mounting edge of the bell housing. This will tell me how much gap there is between the tob and the clutch fingers.

Now the $100,000 question. What should this distance be? What gap am I aiming for?