1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Clutch fork free play

Thread Tools
 
Search this Thread
 
Old 03-11-15, 07:59 PM
  #1  
Full Member

Thread Starter
 
grey'85's Avatar
 
Join Date: Jun 2007
Location: North Bay
Posts: 104
Likes: 0
Received 0 Likes on 0 Posts
Clutch fork free play

I just did a new OEM clutch on my 85 RX7 GS and I would like to know how much free play is normal on the clutch fork. I didn't check before I removed the tranny and want to be sure this is correct before I finish the install. With the tranny bolted to the engine, the clutch fork moves about 1/4" - 3/8" before the release bearing hits the fingers on the pressure plate. Do you guys know if this is normal???
Old 03-11-15, 08:05 PM
  #2  
Lapping = Fapping

iTrader: (13)
 
Jeff20B's Avatar
 
Join Date: Aug 2001
Location: Near Seattle
Posts: 15,725
Received 70 Likes on 64 Posts
The slave cylinder is self-adjusting and will move out to meet the fork. You, however, may need to adjust the rod up under your dash to get the pedal and friction point where you want them.

Be aware that as a clutch disc wears, the friction point moves up higher and higher until it goes above the top of the travel and begins to slip in 5th and 4th first, then slips in 3rd and that's about when it should be changed because then it affects 2nd and eventually 1st, and then you can't drive it anymore.

How thin was the old disc? Where was the friciton point? How stiff did the pedal become? How much effort did it take to push compared with now?
Old 03-11-15, 08:12 PM
  #3  
Full Member

Thread Starter
 
grey'85's Avatar
 
Join Date: Jun 2007
Location: North Bay
Posts: 104
Likes: 0
Received 0 Likes on 0 Posts
I haven't put the slave on yet, just feeling the release fork by hand and it has a little less than 3/8th of an inch fore and aft. Strange thing is I just did a tranny swap on another FB and it had virtually no play in the fork under the same conditions (although that wasn't a new clutch)
Old 03-11-15, 08:27 PM
  #4  
Lapping = Fapping

iTrader: (13)
 
Jeff20B's Avatar
 
Join Date: Aug 2001
Location: Near Seattle
Posts: 15,725
Received 70 Likes on 64 Posts
A new clutch makes the spring fingers lay low, so you will experience bigger play like you're saying. Likewise a used disc will cause the fingers to be raised up and will fill the gap, again like you're saying.
Old 03-11-15, 09:02 PM
  #5  
Full Member

Thread Starter
 
grey'85's Avatar
 
Join Date: Jun 2007
Location: North Bay
Posts: 104
Likes: 0
Received 0 Likes on 0 Posts
Yeah that makes sense, I am still a little concerned that there is zero play on one of them. I feel like it will be hard on the release bearing.
Old 03-11-15, 10:53 PM
  #6  
Lapping = Fapping

iTrader: (13)
 
Jeff20B's Avatar
 
Join Date: Aug 2001
Location: Near Seattle
Posts: 15,725
Received 70 Likes on 64 Posts
It's possible. But then it does have a used disc. It will need to come out again sooner or later.

I find it's not a big deal to do a clutch job in a 1st gen. I just did one like last week, or two weeks ago. I chose to pull the engine because I hate dropping the tranny. Plus it turned out my pilot seal had come loose and let grease leak out. The end of my shaft was ruined by a previous owner so I gotta tear this engine all the way down to change it. Thus I know my setup will have to come back out soon as well, so I went for a risky clutch package with an HD style disc and street strip pressure plate. It paid off because it drives really nicely.
Old 03-13-15, 07:52 AM
  #7  
Full Member

Thread Starter
 
grey'85's Avatar
 
Join Date: Jun 2007
Location: North Bay
Posts: 104
Likes: 0
Received 0 Likes on 0 Posts
Now that the hydraulics are all back together I find that the car with the brand new clutch has an extremely light pedal vs. the car with the used clutch. Both are oem exedy clutches. I can't for the life of me figure out why one would have a much stiffer pedal than the other. Both slave cylinders are moving the clutch fork equally whe the clutch is depressed. Anyone have any ideas what could cause this?
Old 03-13-15, 08:03 AM
  #8  
Lapping = Fapping

iTrader: (13)
 
Jeff20B's Avatar
 
Join Date: Aug 2001
Location: Near Seattle
Posts: 15,725
Received 70 Likes on 64 Posts
A new disc will always result in a lighter pedal if everything else is equal.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
_Tones_
Adaptronic Engine Mgmt - AUS
10
05-25-21 05:37 AM
Jeff20B
1st Generation Specific (1979-1985)
73
09-16-18 07:16 PM



Quick Reply: Clutch fork free play



All times are GMT -5. The time now is 04:31 PM.