88 XJ; AW4 to AX15 Component Issues

R

RAVC1

NAXJA Forum User

Location

Michigan

• Jun 19, 2010

• #1

I have a few hardware compatibility questions I need to ask regarding converting my 88 XJ w/AW4 to the AX15 from my 89 XJ.

1. 98 XJ External slave bell housing, clutch release lever, TOB, etc.
2. 89 XJ AX15, shift lever & knob, etc.
3. 89 Clutch master cylinder & master/slave hydraulic line (i.e., double flare),
4. 89 XJ clutch/brake pedal assembly,
5. 94-95, 97-2004 clutch slave cylinder (NAPA NNC 360047),
6. 89 XJ Renix flywheel & crank sensor (Is the 98 XJ AX15 bell housing ok?),
(a) If machining the bell housing is required for Renix sensor I prefer bell housing without this requirement. What model years are best?
7. 89 XJ pilot bearing,

My concern is with the interface between the older hydraulic line (w/double flare) and the plastic slave. NAPA tells me I simply insert a straight tube (i.e., plastic line w/o any flare or other sealing feature) into a hole and use a roll pin to retain the line on the slave.

Effectively, I need a way to interface my metal double flare line to the plastic slave used on the later model year XJs.

Does anyone have a solution for this? I prefer a single line between master and slave to reduce the risk of leaks. If anyone knows of a different clutch master that will work with my 89 pedal assembly please advise. I did not think this required me to upgrade the master and hydraulic line too, but maybe...I do not have a choice???

Additionally, the NAPA replacement master (NNC 350005) features the same fitting behind the reservoir for the master/slave line that my Renix vintage master has. This is an inconsistency in the after market parts offering. Is this a dealer item?

Thanks,

Rick

 

R

RAVC1

NAXJA Forum User

Location

Michigan

• Jun 20, 2010

• #2

I'm posting more information that should be useful for others in my situation.

Clutch Master Cylinder Distinctions (Internal vs Early External Slave):
From my simple visual inspection it may be safe to simply migrate to the newer clutch master cylinder for Renix vintage applications. The master appears very similar, if not identical, between these 12, or so, model years (84-96 ???) with regard to their depth (parallel to the working cylinder) and height of the fluid reservoir. Effectively, the dimensions of the L-shape of my 89 master is similar, if not identical, to the 96 master I removed from a salvage yard last year. However, this does not mean they have the same working/plunging depth. The Renix vintage master cylinder's have a metal body that can be rebuilt whereas the middle generation clutch master is plastic. The other significant different between the two master cylinders is their mounting hole for the clutch pedal. That is, the hole for the clutch pedal pin is smaller on the newer XJ's plastic hydraulic system.

Clutch Pedal Distinctions (Same model year coverage as above):
The Renix vintage XJ pedal appears to be slightly longer than that for the 94-96 external slave system. The Renix pedal is initially straight then features a small offset for the clutch foot pedal directed away from the brake pedal. The early external slave cylinder clutch pedals feature two offsets; the first directs the pedal arm toward the brake pedal and the second offset directs the foot rest for the clutch further away from the brake pedal than the offset of the Renix vintage clutch pedal foot rest.

Next, as I mentioned above, the pin for mounting the clutch master possesses a larger diameter for the Renix/metal clutch master cylinder/internal slave system than my later model year plastic master/hydraulic line/slave hydraulic system. It looks like these pins can be pressed out of the clutch pedal. However, I suspect it will take some strong pressure to remove the pin. I see no easy way to get between the clutch/brake pedal arms to apply the pressure, so I expect a pulling tool would have to be attached to the either of these clutch pedals to remove the pin.

Summary:
I suspect my situation can be successfully resolved by either of the following two changes:

1. Exchange the master cylinder pin between the two pedals. If I could safely remove the pin from the newer external slave clutch pedal and press it into the older Renix clutch pedal I am working with I should be good to go.

2. I also think I can simply exchange the two clutch pedals. While the Renix vintage pedal does appear to be slightly longer the distance of the master cylinder mounting pin from the pivot bolt for the brake/clutch pedal assembly is identical between these two generations of Cherokee's. In turn, the pin should sweep through the same arc length. This should result in the master cylinder actuating through the same length.

I have to thank Char-Broil for his efforts to help the XJ crowd and hope he and some of the other AX15 swapper's see these posts and comment.

Thanks,

Rick

 

R

RAVC1

NAXJA Forum User

Location

Michigan

• Jul 3, 2010

• #3

These issues were successfully resolved by using the clutch master pin from the newer, early vintage master/slave Cherokee's. I removed the pins from the clutch pedals using a Snap-On ball joint press because my OTC Jeep press clamp is too large to fit into the gap between the clutch pedal and the bracket that holds the pin.

The older internal slave system pins were replaced with the smaller diameter external slave system pins and welded in place.

I'll try to get a few photos posted after I complete the transmission exchange.

Rick

 

1

1988MJ

NAXJA Forum User

Location

Alabama

• Jul 3, 2010

• #4

I dremeled out the plastic master cylinder eye to fit the '88 clutch pedal. Took 5 minutes.

 

R

RAVC1

NAXJA Forum User

Location

Michigan

• Jul 15, 2010

• #5

This may work; I'm uncertain. I chose not to do this because of the thickness of the plastic ring in these master cylinders.

I also have some potential clutch issues that I am hoping someone can answer definitively. I have the full, nearly new, clutch pack off my donor 89 XJ and a new clutch pack for my recently totaled 97 XJ. Both clutch packs are NAPA parts. If you examine their online catalog the part number variation from early (i.e., 87) to mid (i.e., 94-96) feature similar part numbers that are nearly identical. They all feature the same number of clutch disc splines, 10, and a 10.4" raised diaphragm clutch cover/pressure plate.

I am going to begin with the nearly new clutch pack from my 89 XJ and see if it works well with the external slave cylinder/clutch housing.

Does anyone here know if the clutch kits for the XJ production runs from 1987-2001 differ much, if at all?

Search gave me nothing on this issue. I also tried to Google clutch rebuilding and found only specific examples of vehicles far more unique than our Cherokee's.

Thanks,

Rick