Clutch - Converting to an External Slave Cylinder
[There's a possibility that some YJ owners (probably 4-cyl
owners only) will be able to convert their vehicles to use
an external clutch slave cylinder. Given the problems
involved in repairing an internal slave cylinder, this may
be a worthwhile modification to consider if you're already
doing some clutch or transmission work.]
I sent this out to Paul W. a few days ago for a friend of
his who also was contemplating the swap. Anyway, I can't
guarantee the funtionality of this setup yet as I have not
finished the install of the FI 2.5L motor into my Jeep, but
it all looks like it will work OK.
I had to figure out how to do the outside slave with a
bellhousing designed for an inside style because I needed
the 92 YJs bellhousing with the slot cut for the TDC sensor.
I found that with my AX5 trans that all the machining was
still the same, but Jeep had added block off plates to cover
the holes that the external slave passes through. (the early
rigs had the external, my 85 did stock) Basically if his is
the same as what I found he will need:
- an external slave
- external slave spacer
- external slave mounting studs
- external slave style throwout fork
- throwout fork pivot ball (I did have to slightly modify
the seat that this ball sits in)
- rework the hard line from the master as the slave is
plumbed on the opposite side.
Use the clutch pack from your Jeep as there were at least 2
different clutch packs used. The external style throwout
bearing should work with any of them.
The slick way would be to just score a complete bellhousing
from a rig one year earlier and bolt in onto his tranny with
all the appropriate parts.
Wouldn't take long once the tranny was out. BTW I have not
tried or seen this swap done on a 2.8L or 4.0L rig so I am
not sure if everything is the same. I also did it with an
AX5 trans. Others would likely be different, but I still
think it should be possible.
You can convert your YJ to the external slave setup, but it requires a
bunch of parts, and it won't be cheap. Here's what you need:
* external slave cyl and modified master cyl, with connecting hose
* ext slave bellhousing, complete with clutch fork, throwout bearing,
pivot ball, and retainer clip
* AX15 transmission input bearing retainer, or modify yours
The bellhousing and clutch parts, plus the cylinders, can all be taken
from any YJ with the external slave setup. '94 or '95, and possibly
(though I can't confirm this) a TJ or Cherokee with the same tranny.
The master cyl needs to have its mounting holes modified to match
your YJ's firewall stud pattern, plus you need to drill out the hole in
the end of the pushrod to match the pin on your clutch pedal.
The tranny input bearing retainer is different, and you'll need to look
at one from a newer Jeep to see the differences. I don't know what
they are, but I have been told it's possible to machine an older-style
one (like yours) to work.
- Chris Waterman
Just to add to the confusion, I received this email (Feb 2001) from Corey:
I have both styles around my place. I have an external slave on a '86 MJ
4speed, external slave on a '85 XJ 5spd, and most recent aqusition was
an internal slave 5spd from Dave's YJ which is the exact same
drivetrain as my XJ except it was fuel injected and had the internal
Basically they all look like the same bellhousing.
Here is Ryan Egger's reply when someone asked about which brand to
choose when replacing a worn pre '94 YJ's clutch:
First off all I would suggest replacing the internal slave with an
external. This will save you problems in the future and save you money,
cause if that internal slave starts leaking, you have to pull the
tranny. Believe its happened to me twice. All you need is:
- New bell housing from a 94/95 YJ,96 TJ and up
- Front bearing plate for tranny(has sleeve for bearing)
- External slave with at least 8" of hard line from slave to mate to
your original line
- Clutch fork
- New release bearing
The clutch pack to get would be for a 94/95 YJ. Believe me, you will
thank me later. Not only is the slave a lot easier to repair/replace it's
a lot cheaper as well. And its not that much more work at all. I would
say, max an hour.
In case anyone is tired of pulling the transmission on your
1992 Wrangler Just to replace a slave cylinder I'm passing
along this conversion info that I acquired when I converted
mine to the 1994 style.
The clutch, transmission and front bearing retainer are the
same on 1992 and 1994. This conversion only requires a 1994
bellhousing, clutch fork, release bearing and a 1994
Master/Slave cylinder. This is for 2.5 W/AX5
Bellhousing Salvage Yard P/N 408-00867 USD$70
Clutch Fork xtremeterrain.com P/N 52107555 USD$30
Release Bearing BCA P/N 614093 USD$41
Master/Slave Assy. xtremeterrain.com P/N 52104113 USD$100
For less than $300 you can eliminate a major pain.