1986 diesel Jeep Comanche TDI conversion

john.jackson9213

Top Post Dawg
Joined
Mar 14, 2007
Location
Miramar, Ca. (Think Top Gun)
TDI
1996 B4V
Took this picture of the master cylinder after we bled the clutch:




Here is what it looks like today after a few days of use:



Clutch is still working fine right now. I am going to top off the master and drive it some more.

Yes, the color of the fluid has changed from clear to a gray color.

My cheap USB inspection camera was having a problem getting past the clutch lines, so I will be looking for a better inspection camera in the mean time.
 

evguy1

Vendor
Joined
Feb 8, 2014
Location
Erington, BC, Canada
TDI
2000 Jeep Cherokee TDI, 2008 Jeep JKU TDI
Nasty looking fluid.
New master and new slave?? Where is that fluid coming from?
New lines?
Can you bleed the system at the slave?
If you can then I would bleed that crap out of there ASAP.
Bleed it till the fluid is clean.
 

john.jackson9213

Top Post Dawg
Joined
Mar 14, 2007
Location
Miramar, Ca. (Think Top Gun)
TDI
1996 B4V
Nasty looking fluid.
New master and new slave?? Where is that fluid coming from?
New lines?
Can you bleed the system at the slave?
If you can then I would bleed that crap out of there ASAP.
Bleed it till the fluid is clean.

Master and Slave have each been replaced twice. Whitbread bled the fluid till all he was getting was clear over Easter when he was in Calif. A few days later, the fluid was low and crappy again. My son and I bled it again till past being clear.

This morning, a buddy told me to replace the steel hydraulic clutch line next. He thinks the old line is failing from the inside. That makes a lot of sense to me.

So my next project is to find a new clutch line and replace the old one. Then bleed the heck out of it a couple more times and see what that does.

John
 

A-man930

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Jul 29, 2014
Location
St. Louis
TDI
Planning Stages: ALH Jeep MJ
All this master and slave swapping and the line/hose is still original? C'mon now... :rolleyes:
 

evguy1

Vendor
Joined
Feb 8, 2014
Location
Erington, BC, Canada
TDI
2000 Jeep Cherokee TDI, 2008 Jeep JKU TDI
Usually those clutch lines are the same as brake lines and available in different lengths from auto parts stores. Not sure about yours.
 

john.jackson9213

Top Post Dawg
Joined
Mar 14, 2007
Location
Miramar, Ca. (Think Top Gun)
TDI
1996 B4V
All this master and slave swapping and the line/hose is still original? C'mon now... :rolleyes:
No, not original and somewhat "custom", all steel in several different parts. Transmission was also changed from AX -5 to AX-15.

Ordered this clutch line from Amazon. It is for the 1990 Cherokee/Comanche with AX-15 transmission. Should be here on Friday. About $20 with tax and free 2 day delivery.


DORMAN H38938 {#53005923} Info
 

A-man930

Veteran Member
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Jul 29, 2014
Location
St. Louis
TDI
Planning Stages: ALH Jeep MJ
No, not original and somewhat "custom", all steel in several different parts. Transmission was also changed from AX -5 to AX-15.

Ordered this clutch line from Amazon. It is for the 1990 Cherokee/Comanche with AX-15 transmission. Should be here on Friday. About $20 with tax and free 2 day delivery.


DORMAN H38938 {#53005923} Info
Just so you know I meant no disrespect with that comment, just couldn't help but be reminded of how easy it can be to overlook things sometimes. (in the middle of one of those times right now actually...)

That being said, I'm a bit confused/concerned; the line coming from the master to the slave is all steel? This sounds 1.unlikely to contribute to nasty fluid and 2. is asking for trouble with the movement between these parts. The line you ordered has a giant section of it made flexible for this reason.
 

john.jackson9213

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Joined
Mar 14, 2007
Location
Miramar, Ca. (Think Top Gun)
TDI
1996 B4V
A-man,

One of the reasons we post here is to get the insights, observations and wisdom of others. So I have zero problems with anyone posting thoughts, etc.
But if I have to drop the transmission to change the internal slave, then I really want to consider going to the external slave as Rob has posted.
 

john.jackson9213

Top Post Dawg
Joined
Mar 14, 2007
Location
Miramar, Ca. (Think Top Gun)
TDI
1996 B4V
If that doesn't work, it is possible to convert to an external slave cylinder on the AX15.
You might want to have a look at this thread, bunch of info on that trans: http://www.naxja.org/forum/showthread.php?t=1121647
As for the conversion, a little info here: http://www.naxja.org/forum/showthread.php?t=965590

Rob,
Thanks for the links. If I have to drop the transmission to replace the internal slave cylinder, I will convert to the external slave. Right now I am still closely watching the clutch fluid level and driving the truck around a few times a week.

I kept a sample of the clutch fluid in an open glass container to allow the brake fluid to evaporate just to be sure there were no metal particles left in the system from the last master cylinder change. At this point, the sample looks to be free of any metal particles.

Monday, I filled the tank for the first time. Took 20.5 gallons, had at least 835 km since Whitbread filled it up last September. Got at least 25.5 MPG and perhaps 27.5 MPG when I figure in the larger diameter tires on the truck compared to stock tires. This included all the tuning and testing that Whitbread did last September.

My grandson is a diesel tech at a Dodge/Ram/Jeep dealer. He was visiting yesterday and inspected the truck. Dominic was quite pleased with the TDI engine conversion, when I asked him how it compared to his 4 liter Cherokee - he thought the TDI had more torque than the 4.0. He also noticed clutch fluid weeping from the bell housing and suspects a leak at the internal slave. He also suggested if I have to drop the trans, I convert the system to the external slave.

All for now, I will update in a couple of weeks.
 

Rob Mayercik

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Joined
Dec 19, 2001
Location
NJ, U.S.A.
TDI
2002 Jetta GLS, Baltic Green/Beige
Rob,
Thanks for the links. If I have to drop the transmission to replace the internal slave cylinder, I will convert to the external slave. Right now I am still closely watching the clutch fluid level and driving the truck around a few times a week.
Glad I was able to point you at something that could come in handy. Of course, if you don't need to drop the trans for a long time, that's even better. (less work = more good)

My grandson is a diesel tech at a Dodge/Ram/Jeep dealer. He was visiting yesterday and inspected the truck. Dominic was quite pleased with the TDI engine conversion, when I asked him how it compared to his 4 liter Cherokee - he thought the TDI had more torque than the 4.0. He also noticed clutch fluid weeping from the bell housing and suspects a leak at the internal slave. He also suggested if I have to drop the trans, I convert the system to the external slave.
It must be because the TDI hits its torque peak earlier that it feels torquier - the 4.0 is rated 225lb-ft at 3000rpm to the TDI's 155lb-ft at 1800rpm, because the TDI feels like a hot-rod locomotive on a 50-80 top gear pull.

I've always thought a slightly modded ALH (11mm pump, a nozzle upgrade, and a mild tune) could get a stock XJ or MJ into 30mpg territory; and your numbers so far sound like you're right on the verge of getting that, even with larger-than-stock tires and a slightly older generation engine - sweet!.

Any chance of getting a drivability report on this thing offroad in the rocks once you've got the clutch fluid leak resolved? Inquiring minds want to know...
 

john.jackson9213

Top Post Dawg
Joined
Mar 14, 2007
Location
Miramar, Ca. (Think Top Gun)
TDI
1996 B4V
Any chance of getting a drivability report on this thing offroad in the rocks once you've got the clutch fluid leak resolved? Inquiring minds want to know...
Rob,

The truck is 2 wheel drive, not 4x4. Whitbread asked if I wanted to convert the truck to 4x4 while it was in his shop and I said no. I have never been into off roading and didn't want to deal with the engine conversion issues and possible 4x4 conversion issues at the same time.

The engine has been upgraded with an 11mm rebuilt Giles pump, Race 520 nozzles, GTC1549VZ turbo (from 170 hp VW) and a custom tune by TDtuning. Original plan was an identical engine to the one I have been running for the last couple of years in my Passat. Whitbread had TDtuning cut back on fuel till zero smoke. So I am down a bit from the 173hp/315tq tune that would slip the clutch in the Passat.

We put stronger 12.9 head bolts on this engine just to give us more room to install a more aggressive future tune and more boost than the Passat engine if we wanted to go in that direction.
 

A-man930

Veteran Member
Joined
Jul 29, 2014
Location
St. Louis
TDI
Planning Stages: ALH Jeep MJ
I've always thought a slightly modded ALH (11mm pump, a nozzle upgrade, and a mild tune) could get a stock XJ or MJ into 30mpg territory
I'm dying to realize this when I do my ALH conversion; gearing is probably as big a factor as engine though.
I'm also looking forward to continued reports on MPG and drivability. Any chances of a dyno pull? ;)
 

john.jackson9213

Top Post Dawg
Joined
Mar 14, 2007
Location
Miramar, Ca. (Think Top Gun)
TDI
1996 B4V
I would love to do a dyno pull one of these days. But right now, much other stuff to sort out about the truck. In addition to the clutch issue:

1) Tires look good, but are 2000 build date. Need to be replaced before I get stuck on side of road with flat.
2) Existing wheels are 6 inches wide - too small for 235 or 225/75x15 tires.
3) Original 195/75x15 tires are super hard to locate now.
4) No A/C ever installed in truck. Needs to be done if I want to drive the truck much.

There is more, but you get the idea.
 

Rob Mayercik

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Dec 19, 2001
Location
NJ, U.S.A.
TDI
2002 Jetta GLS, Baltic Green/Beige
Ah, missed the 2WD part, no problem.

If you ever decide to go 4x4, it'll be a lot easier than the ALH swap - the 2WD tube and the 4x4 front axle both use the same mounts, it's a bolt-in (do yourself a favor and avoid a front axle out of anything newer than '99 - you'd want the high pinion, and in 2000 they went low-pinion on the D30). Tcase and driveshafts easy, just get 'em off a junker. Not sure on the trans, might be as simple as an output housing swap, or just bolt up a good 4WD AX15 in place of what you've got.

At any rate, focus on setting it up for what YOU want it to do (especially the A/C - I agree that's a non-negotiable).
 

john.jackson9213

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Joined
Mar 14, 2007
Location
Miramar, Ca. (Think Top Gun)
TDI
1996 B4V
My son is driving about 125 miles per day round trip to work, so he has been using the truck and putting quite a few miles on it. So far the clutch leak is minimal. Only requires reasonable checking and no more than 2 top offs with DOT 3 brake fluid. But the long term solution is to change from an internal slave to an external slave cylinder. To that end, I have been checking Craigslist for the conversion parts. Think I have found them about an hour and a half away. So will be checking them out this weekend.


The stock 6 inch wide steel wheels had 18 year old 235/75 x 15 tires. Besides the age of the tires, they rubbed on the lower control arms at full lock. About 2 weeks ago I found a set of aluminumn 7 inch wide stock Jeep wheels with decent 8 year old 235/75 x 15 Goodyear Wranglers on Craigslist. I got all four of them for $200 and another $60 to have the old tires on the steel wheels disposed of. First thing we noticed with the new wheel and tire combination had no interference with the lower control arms at full lock.


The TDI engine is running great at this point. Odometer now shows 136569 km. That is about 4300 km (about 2675 miles) since the TDI engine conversion. More in a couple of weeks.
 
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Rob Mayercik

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Location
NJ, U.S.A.
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A couple washers under each of the steering stops would also have resolved the rubbing issue (did that on my Cherokee years ago), but given the age of the tires that was definitely the priority.

How's the MPG holding up?
 

john.jackson9213

Top Post Dawg
Joined
Mar 14, 2007
Location
Miramar, Ca. (Think Top Gun)
TDI
1996 B4V
How's the MPG holding up?

My son doesn't bother to keep any records, so I don't know. He is spending much less on fuel with the diesel than with the 4.0 Comanche!



He returned the truck this morning because the ignition switch seems to be "acting up". So I will check it out and likely replace the complete switch if I can find a NOS part. The switch is a stock GM part from the mid 80's.
 

john.jackson9213

Top Post Dawg
Joined
Mar 14, 2007
Location
Miramar, Ca. (Think Top Gun)
TDI
1996 B4V
Long time and no update. Ignition switch "issue" seemed to go away when I kept a battery charger hooked up for a day or so.

Last Wednesday, Matt Whitbread was out here for other reasons. But he spent the day solving my clutch issues. We converted the internal slave cylinder to an external slave. Clutch now acts as expected.
Matt had changed the internal slave with a new one twice and both were Garbage.
Even the new external slave had multiple problems. Frist the NAPA external slave did not come with a bleeder screw. Wasted a couple of hours trying to locate one. Finally got a used external slave from a local Jeep salvage yard who waited half an hour after closing for us.
Just as we were a quarter mile away from the yard, we find the road closed by police and fire department because of a car on fire.
Finally make it to the salvage yard, buy a used external slave and go back home.
New slave is not working. Inspection finally shows new slave did not have bleeder hole drilled out from factory. Drill out hole by hand, install used bleeder. Finally, bleed clutch totally.
First test was delightful! Works just like it is supposed to. Amazing. 3 different, brand new slave cylinders with problems right out of the box.
Shifting is great now, but more testing needed.
Did I say it has been great watching Whitbread working on this project?
 

john.jackson9213

Top Post Dawg
Joined
Mar 14, 2007
Location
Miramar, Ca. (Think Top Gun)
TDI
1996 B4V
Update:


"Ignition switch" issue raised it's head again 10 days ago. Son dropped truck at my house and it failed to restart. Battery was low, so recharged. That didn't help. But I could hear starter relay clicking, so it was not the ignition switch and looked like a bad starter.


Got the correct information and part number for a new replacement starter and had truck towed to shop for repair. Turns out they found a broken wire to the starter. Replaced the wire and truck now runs fine.



Except now the tach has stopped working!
 

john.jackson9213

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Joined
Mar 14, 2007
Location
Miramar, Ca. (Think Top Gun)
TDI
1996 B4V
Took the Comanche on a 165 mile round trip Saturday morning. Happy to report the truck ran just fine. No incidents at all. Transmission and the new external slave cylinder have been working exactly like they should.

I will fill up the tank, record the odometer reading on Tuesday and actually start a MPG check on Tuesday. Likely will take me more than a month to burn 20+ gallons of diesel.
 

john.jackson9213

Top Post Dawg
Joined
Mar 14, 2007
Location
Miramar, Ca. (Think Top Gun)
TDI
1996 B4V
Never did fill up the fuel tank. Instead, my son borrowed the truck again and has had it up to last Thursday morning.


The TDI Jeep Comanche was stolen out of his parking place. This may be the sad end to the project.



We will see if the truck is recovered and what damage is done. But I am not hopeful.
 

TDIDaveNH

Left Lane Coal Roller at Large
Joined
Feb 17, 2009
Location
North Conway, NH
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'97 Passat x2
:eek:OMG Did you have any sort of tracking device on it?
Really sorry to hear that. The time, money and dedication these projects take is significant. Let's hope it pops up on the dragnet somewhere.
 
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Steve Addy

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Aug 7, 2002
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Iowa
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97 Mk3
John I am so sorry to hear this, you've put so much time and energy into that project.


Hoping that you recover it and that it hasn't been abused.



Steve
 

vtpsd

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Aug 15, 2013
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Vermont
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03 jsw TDI, audi 90 AHU swap
I'm really sorry to hear this. I've enjoyed following along with the project.
 

jmodge

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Damn! I never thought of a tracking device before. Too late in this case, but a good subject, best wishes
 

ToddA1

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'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
Geez, that’s disheartening... I hope they catch the scumbags.

I’ve been thinking of stated value insurance, for my vehicles.

-Todd
 

TDIMeister

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TDI
Ahh! So sorry to hear of this John! I hope you can recovery it and/or get a good insurance settlement.
 
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