clutch problem

[dmiller]

using a wilwood pull type slave cyl. on a mustang clutch setup, the arm releases the clutch by moving toward the front of the car.

worked very well until yesterday.

first symptom of problem was that could not engage reverse without gear mesh noise.

i adjusted the linkage to the slave cyl and clutch release arm to allow more allowance for release, but then the clutch slipped.

i bled the system and noted that when the bleed valve was open, the clutch pedal would go all the way to the floor board with little resistance. but when the the bled valve was closed, the clutch pedal would come to a stop well short of the floor.

i disconnected the linkage between the slave cyl and the clutch, and the clutch pedal still will not travel to the floor, even with no physical linkage to the clutch.

i suspect that i need a new slave cyl.

please advise.

[clayfoushee]

What kind of trannie? Lee Dahmer is a Unique dealer and builder in my area, who's also done a lot of racing in his.....top-loader w/ a 428, and he uses the same set-up as mine. I rely on him constantly, and never let down. Lee claims that a little grinding into reverse is normal with a top loader when the fluid is hot. The syncros are not high-tech.

I'm passing this on, because Lee avoids computers and the internet like the plague, and we just had that discussion last week.

Mine does exactly that, when hot. Cold is smooth as silk. One thing that helps is putting it in first and engaging a little before trying to go to reverse. It's possible you had the right set-up before you changed it, and I've heard many others report the gear grind into reverse issue with toploaders as well.

Of course, all this is academic if we're not talking about the toploader.

Clay

'98 Unique #9299, 427FE side oiler, top-loader (close), 3.31 rear

Annapolis, MD

[pgermond]

The single biggest thing that gave me the most grief with my build were the hydraulics. The clutch adjustment took a lot of monkeying around with, so my response is about the same as Clay's (if you have a top loader). I have found that after 20-30 minutes on the road it doesn't want to go into reverse too easy. Could be the clutch heating up, the hydraulic fluid getting hot, or ???? I either do some double-clutching or just shut 'er down, put it in reverse, and restart. I've learned to live with it for now.

The clutch adjustment is very fussy... you have to have some free-movement on the adjusting rod (not much - just enough so you can move it between your fingers), otherwise the clutch will not fully engage with the result being slippage.

As for your question regarding the slave cylinder.... if it were me I would give Wilwood a call (don't e-mail for technical advice unless your willing to wait until July to get a response).

Phil

427 Roadster, #4279436
Southern Automotive FE
3:31 and Toploader

Roseville (N.Cal)

[dmiller]

i've convinced myself that i have a failed slave cyl. but will call wilwood tues. am.

the brake fluid was "brown" not clear so that may have been part of problem, but with new fluid, no better.

prior to today, it was great. something changed. and it was a rapid deteriation.

thanks for help.

doug

[Poorboy]

Doug,
Reverse in most transmissions including the top loaders have No synchronizers. You have to make sure the car is dead stopped befor trying to put it in reverse. Clutch adjustment is very credical(sp)you must have a little free travel or you will burn up the clutch release bearing.
Sounds like the fluid is getting hot and boiling causing the clutch too quit working. Lines being to close to the headers will cause this. You might try moving the line or insinulate it from the heat.

[pgermond]

Poorboy has a good point - insulation. I didn't mention that I have heat reflective material covering all my hydraulic lines that are anywhere near the headers. Hell, I even wrapped the slave cylinder. I'll most likely do some re-routing this fall/winter. Better safe than sorry ;)

Phil

427 Roadster, #4279436
Southern Automotive FE
3:31 and Toploader

Roseville (N.Cal)

[clayfoushee]

Good catch Poorboy....forgot to include the insulation deal in my original post. Dahmer also mentioned that. My brake and clutch lines are insulated with that foil-covered stuff. When hot, my grinding into reverse is fairly slight, if I come to a complete stop, and shift into another gear first. If I don't it sounds very nasty. As I said before, it's smooth as silk, cold.

My theory is that your original setting before you messed with it, was probably close to OK if you had no issues before. The last thing you want is the clutch slipping. You're better off, grinding a little during that occasional shift into reverse.

Do you remember where you had it set before you changed it?

Clay

'98 Unique #9299, 427FE side oiler, top-loader (close), 3.31 rear

Annapolis, MD

[dmiller]

i think you are right about the hot fluid, but now with new fluid, it doesn't work, and the clutch pedal will not go to the floor board without the slave cyl's bleed line being open. with the bleed valve open, the clutch pedal moves freely all the way to the floor. but with the bleed closed, it only moves part way, then get very hard.

i had planned to insulate the clutch slave and lines. but everything was working so well, that i didn't want to take the time, and this is probably the result. a fried slave cyl.

appreciate your help and ideas.

will be on phone to wilwood tomorrow.

doug

[clayfoushee]

Possibly....but have you changed to adjustment back to where you thought it was before?

Clay

'98 Unique #9299, 427FE side oiler, top-loader (close), 3.31 rear

Annapolis, MD

[spd4me]

dmiller
I've got one of those Wilwood pull type slave cylinders I plan to install this week end. I'll mount mine between clutch arm and under seat. Before you do anything, measure the distance the slave rod is moving. When full of fluid, it may not need to go all way to floor. Wilwood rep told me I could expect 1.3" of travel. If it the same size bore as the master cylinder then it should only take 1.3" of clutch pedal movement. Right now my master is 5/8" pushing on a Lockheed 1" slave so it take more petal movement to move slave. Another thing that could cause problem is bellhousing not being centered on crankshaft. Could be putting just enough bind on transmission shaft to keep it spinning. Check article on Lakewood bellhousings on Cobra Club. Mine grinds so bad I have to turn engine off to engage.

[dmiller]

all of the comments are valid, and i appreciate them.

i've decided that i've fried the slave, have a new one on order, be here wed.

the lenght of motion now, is much less than before. and i can adjust the release arm such that i can shift, but then the clutch slips, so i doubt that the bell housing has shifted and binding the tranny.

i plan to insulate the line and the cyl when reinstalled.

once again, thanks

i'll report success or failure tomorrow nite.

doug

[Mike Geddes]

Get an Automatic.....No problems.
Mike

Mike Geddes

[dmiller]

mike, i don't know how to drive an automatic.

what does one do with the left foot?

how doing?

doug

[JerryBP]

on master vs slave movement, if both are the same size,
the master should travel the same amount as the slave,
that is the shaft on the master not the peddle travel

what does one do with the left foot?
stomp a hole in the floarboard trying to get clutch to release

Work in Progress, Unique 427-9429 400+hp 351C Tremec 3550-2 5spd Coal Black
by Bruce, Greg & Jerry Porter Caldwell, Ohio

[gasman]

Insulate the lines before changing the slave. I recently replaced the clutch, fly wheel and throw out bearing. The fluid was black from header heat, which had something to do with the clutch failure. Rebuilt the slave at the same time. The new clutch would not engage when the fluid got hot, it was fine when cool. Adjusting the linkage allowed meshing into 1st thru 4th, but not reverse. Insulated the lines and everything was cool....pun intended. I'm re-routing all of my master cylinder lines over the foot box this winter.

Steve Foushee
Unique #4279389

[eliminator]

One other bit of advice, on any of these cars you should change the fluid every year. The clutch fluid gets the best dose of heat and the rear brake fluid runs a close second. So just spend a little time and bleed out the lines and install new fluid. Dosn't take much time or fluid. Anytime the fluid in the master cylinders is turning a dark color you need a fluid change, if this is happening in less than a year you need to insulate the lines and or re-route.

Rick
#4279405