you find the gear ratio in the lower left
from top to bottom:
3.73 tow package or Diesel
4.11 Limited Slip(Trac-loc)
3.73 Limited Slip( my Diesel)

Even the AX-15 gearing is different for the Diesel( but only the first gear, all others are the same)
I also have no idea 'bout the Chinese(some europeans are changing the front and the front fender to get a modern look.)
Don't get me wrong - I have absolute no ideas about the gassers- I just like the Diesel and also hate it because I have constantly something to repair on it.

Exactly,getting a bit more offroad capability - I found that the common Jeep sites are mostly about throwing a basket on the roof and adding about 12 to 15 walmart beams all over the Jeep.

Armor, protection and bigger tires are a bit tricky in germany. Police and safety inspection do not like it.
So I have to find uncommon ways to improve it- which is difficult, because those Jeep sites do not care about that ( makes senses- if nobody has to think about it)

 

OK now I see them, couldn't make out some of the numbers when I was looking at them before. LOL! Must be time for a new pair of glasses!

I've only actually looked at a couple of the tags before - like I said, most of the time they're missing due to someone leaving them off when doing a diff fluid change. Those don't look like what I was remembering. Seems like the ones I remember were about 1/3 that long, had 1 bolt hole, and raised numbers punched into the tag from the back side. Maybe my memory is failing me too!

Interesting. They put the AX5 in the only diesel they ever offered in the US - the 2.1 Renault turbo diesel. Talk about another winner. The Renault doesn't have a very good reliability record either, and parts are pretty much impossible to get because the only other vehicles ever sold in the US with the same engine were some of the small "Mini-Winnie" Winnebagos.

How do they feel about the molded heavy-guage steel quarter panel and lower door guards? What about "nerf bars" or other rocker panel protection? I'm not quite sure what you mean when you talk about putting "walmart beams" all over the Jeep...

 

I found my aftermarket tach. I hooked it up to the Jeep on the 4 cyl setting. It would go up and down when I revved the engine, but it was reading too low, about 250 RPM at idle. I am assuming the OM617 idles at about 750, that's where my OM603 idles. I removed the factory tach from the dash, I am going to play around and see if I can get it to read the proper RPM.
I think there is a resisitor you can change to change the RPM's.

John

 

You are exactly right. I have done this before. About 20 years ago I modified a standard aftermarket tach like you're describing (it had a switch to select between 4-6-8 cylinders) to work on a 2 cylinder motor.

IIRC this type of aftermarket tach is really just a volt meter reading average voltage across a capacitor/resistor network. Electrical pulses from the cylinder (usually picked up and "converted" to the correct voltage/current level by an inductive probe OR by being connected directly to the 12V side of the ignition coil) charge the capacitor - which is constantly being discharged through the resistor. The lower the value of the resistor (less resistance to current flow) the quicker the capacitor discharges and the lower the average voltage (displayed as lower RPMs). BTW, what did you hook the aftermarket tach up to on the diesel - the factory MB tach module?

You are also correct about the idle speed of the OM617 being about 750 RPMs - that is about what the idle is on my Mercedes 300 CD. So, if your tach is reading 250 RPMs at idle you'll need to look at the resistor that gets switched into the circuit for the 4-cylinder setting, and replace it with one that has 3x more resistance. If it is 1k Ohm, replace it with one that is 3k Ohm to reduce the capacitor discharge rate to 1/3 of what it was and your tach will read 3x higher - about 750 RPMs.

If you can't get one that is pretty close to 3x the resistance of the one already in the circuit you may have to replace it with a little potentiometer with the appropriate resistance range and adjust it to the right resistance to get the correct RPM reading. Either that or hook up some resistors in series or parallel to get the proper resistance value. The potentiometer will usually be the easier route and you may be able to get one of the fine-adjustment screw-type with the right resistance range at Radio Shack. If not, try digikey.com - you can get just about ANY value of any kind of electronic component you want or need through them.

You may already know all this, but I thought I'd volunteer what I did once upon a time that worked perfectly - just in case. I wish the 4.3L I'm using had some kind of provision for a tach. Unfortunately the cars they came in weren't offered with a tach, so there is NOTHING on the motor to generate the neccessary RPM-dependant signal. I'm going to have to jerry-rig something or buy a alternator-driven tach...

Good luck with it!

 

Thank you for answering my questions.
With walmart beams I mean those cheap aux lights all over the Jeep.

I would like to raise the Jeep to 2 real inches. That should be enough for me.
I'm also interested to beef up the steering linkage- it does not look very "HD"

An ARB locker is in the D35- I know, not the best. But bigger axles are very uncommon over here and hard to get. I also think about getting a locker in the front.

I know the Renault 80hp engine. It's an awful engine, way to small for that Jeep size

The AX 5 isn't cool at all too, I guess.

 

I got the factory tach sort-of working. I jumpered a resistor between the signal post and one of the unused posts on the tach, I think it was 680 ohm. It goes up and down, but only reads 250 RPM at idle. I tried piggybacking various resistors in parallel with the resistors on the circuit board, but that did not change. I tried a pot too, would not raise the RPM's. There are a couple of IC chips on the tach circuit board, one of them probably has the resistance to control the RPM's. I thought about playing with the aftermarket tach like CheaperJeeper suggested, but i'd rather make the factory tach work if possible. I at least got the signal from the Benz amplifier to run the tach, it's just not accurate. Maybe I could add another pin 180 degrees on the balancer, then compensate with resistors........

John

 

I messed with the tach some more today. I found a website that shows how to modify the tach with different resistors. The site is for Fieros, and the circuit board looks similar to the one in the Jeep dash. I added a 320 ohm resistor between the signal post and one of the unused posts. I tried a jumper wire and various values of resistors, the 320 ohm worked the best. Without the resistor between the posts, the tach would read no signal at all. I added two 320K ohm resistors in series and cut the trace to the IC chip to change the resistance. It idles right at 750, goes up and down, but tops out at 2000. I might not have it wired correctly. I tried a single 320K resistor at the bottom, and it idled at 500, so I think i'm in the right circuit. I'm no electronics expert, don't really know what the hell i'm doing, I just played around with it.

Here are two pics of the back of the tach: The resistor toward the top of the board is the 320 ohm. The two wired in series are 320K each. The blue pen is pointing to the trace I cut. It's the third pin down on the IC chip. Now I need to figure out how to make it read higher!!!

Here is a link to the site:
Tachometer System

I will let you guys know if I figure out how to fix it properly, at least for now, it works up to 2000 RPM!!!

John

 

Benzer1,

Good job! Thanks for all the info. Sorry, for all your struggles!

I am researching a diesel BOMB of a 89-91 Jeep Cherokee myself. I hope you can help with a little info. I think I am going to have to go measure one myself!

Do you remember the height, width and length of your OM617 or know where I can get the info?
Do you know the width between the frame rails in your Cherokee?

Thanks!

 

One last tidbit for you. The 87 and up XJs almost all had an inline 4.0 6 cylinder. Perfectly sized for the OM617 inline 5 cylinder...

 

Yeah, I just found a good om617 that I'm going to put in my '87 Cherokee. I have a 6 inch lift, so I'm pretty sure the pitman arm should work. Will let you guys know how everything goes with the oil pan situation.

rocking: