Help me piece together what I have part wise for later 4wd Conversion

[ExpatMJGuy]

So I have an 86 parts MJ for my being restored 88 MJ and a 99 Parts XJ that has parts planned to go towards my MJ and other 01 XJ.  

 

I've been trying to do some homework and piece together what I have to see if I can make it work and what I will need and start slowly accumulating parts as they become available for a decent price.  I've done some work but still haven't found stock gear ratios for the DANA 30.  Plus I'll admit I went to automotive school 14 years ago and since I haven't used it so I don't remember much about calculating gear ratios.

 

With that said here's what I have and what I know about it.  I plan to leave all vehicles at current heights due to possibly moving internationally where lift kits are much more restrictive.

 

Also nothing has tags anymore so I'm going off what I have found here in the forums...

 

1986 2.8v6 MJ (Parts Jeep)

useless AX-5 4wd with np207

stock ride height

 

DANA 30 CAD axle

DANA 35 C-Clip 27 Spline (2.8v6 had fuel saver package 3.31:1)

 

 

 

1988 4.0 MJ 2wd Pioneer (Being Restored)

Currently has Peugeot 2wd Transmission

Intend using AX-15 from 1999 parts XJ with NP 231

stock ride height don't plan on doing anything difficult with it but would like to get it on beaches\ fire break type trails.

 

2wd Float Axle

DANA 35 C-Clip 27 Spline (4.0 w/Manual came with 3.07:1)

 

 

 

1999 4.0 XJ 4WD Sport (Parts Jeep)

AX-15 planning to move to 88MJ along with NP231

3 in cheap crap lift with 31s 

 

DANA 30 High Pinion Non-CAD Axle

Chrysler 8.25 29 Spline (4.0 w/Manual came with 3.07:1) {Have paperwork where lift was installed no mention of gear change}

 

This info was found in the factory build order:

DJH	Dana M30/181MM Front Axle
DMM	AXLE RATIO - 3.07
DRA	REAR AXLE - CORPORATE 8.25

 

 

2001 4.0 XJ Limited (Being Restored)

Will Need 4wd AW4 Transmission with Transfer Case

3in Rough Country Lift w/ 246/75/16 tires 

 

2WD Float Axle

Chrysler 8.25 29 Spline (4.0 w/Auto “Towing Package”  came with 3.73:1)

 

This info was found in the factory build order:

DMD	AXLE RATIO - 3.55
DRA	REAR AXLE - CORPORATE 8.25

 

 

I have also found online a guy selling a non-CAD Dana 30 with 3:55 gear set for $80.  If useful I might get it due to lack of space for pulling a second vehicle into my garage at once.  I also understand that non-CAD axles tend to be stronger.  I'm struggling to understand what I can mix and match with what.  If I'm reading this right buy the used front axle, put it in the 01 XJ to match the new Auto, then use the front axle off the 99 XJ for the 88 MJ?  Then sell or scrap the CAD DANA 30?  I can then use the 2wd axles to keep my parts vehicles rolling for now.  Yeah?  I'm not crazy? Brain hurts! 

 

[eaglescout526]

Does your axles still have the service tag ID plate on the cover? That usually has an AMC part number(or Chrysler if it’s newer) and the ratio beneath the part number. 

[ExpatMJGuy]

I’m not finding tags on ANYTHING other than what’s on the d35 diff cover which isn’t giving me much.

 

86MJ

 

88MJ

 

99 XJ

 

 

01XJ

[eaglescout526]

3 minutes ago, ExpatMJGuy said:

I see the tag for that one right there going towards the pass side of the pumpkin. That piece of metal sticking up is the tag for that one. I definitely don’t see it on the others. 

[Pete M]

for rear axles and non-cad fronts, you'll want to rotate the axle exactly twice while counting the number of times the pinion rotates.  3 and a half times is 3.55 etc.  admittedly this can be challenging on a loose axle in a junkyard because it requires the other side axle to remain stationary. 

[ExpatMJGuy]

24 minutes ago, Pete M said:

for rear axles and non-cad fronts, you'll want to rotate the axle exactly twice while counting the number of times the pinion rotates.  3 and a half times is 3.55 etc.  admittedly this can be challenging on a loose axle in a junkyard because it requires the other side axle to remain stationary. 

Why didn’t I think of that?!? 
 

Here’s what I’m stuck on.  How does 3.55 work with the 3.73?  Is it compensation for the length of the drive shaft?

 

 What is the standard ratio for a d30 with the manual 3.07 rear drive shaft? Should rotate 3 even up front?

[Pete M]

 

14 minutes ago, ExpatMJGuy said:

 How does 3.55 work with the 3.73? 

 

 

I... don't know what it is you're asking?  the driveshafts are completely independent of the ratios.

 

the number is the ratio of teeth inside (ring gear vs pinion gear).  the front axle and the rear axle ratios must match.  the higher the ratio number (which is unfortunately called "lower gears") the better it is for bigger tires (within reason but we're dealing with factory ratios here so bigger = better).

[ExpatMJGuy]

2 minutes ago, Pete M said:

 

 

 

I... don't know what it is you're asking?  the driveshafts are completely independent of the ratios.

 

the number is the ratio of teeth inside (ring gear vs pinion gear).  the front axle and the rear axle ratios must match.  the higher the ratio number (which is unfortunately called "lower gears") the better it is for bigger tires (within reason but we're dealing with factory ratios here so bigger = better).

I’m trying to prevent gear binding.  Ensuring I have a gear ratio in front that works with gear ratio in the back.

 

Numbers aren’t lining up exactly between the front and back.  I was thinking about when you said spin the tires and count the amount of times the pinion rotates and said drive shaft on accident.  I was asking about the 3.07 manual.  The matching d30 front axle pinion should only rotate 3 times correct?

[ExpatMJGuy]

1 hour ago, eaglescout526 said:

I see the tag for that one right there going towards the pass side of the pumpkin. That piece of metal sticking up is the tag for that one. I definitely don’t see it on the others. 

It might be on backwards.  I did try to rub the grease off and when I did all I got was blank tag.

[Pete M]

6 minutes ago, ExpatMJGuy said:

I’m trying to prevent gear binding.  Ensuring I have a gear ratio in front that works with gear ratio in the back.

 

Numbers aren’t lining up exactly between the front and back.  I was thinking about when you said spin the tires and count the amount of times the pinion rotates and said drive shaft on accident.  I was asking about the 3.07 manual.  The matching d30 front axle pinion should only rotate 3 times correct?

 

yes.  just over 3 times is 3.07 and just over 4 times is 4.10

[ExpatMJGuy]

 

I got a lot of info off this chart.  If I'm understanding correctly you can have up to 6 Dana30 front axles based on the information in the table above?  And looking at this I caught myself on my 01 XJ.  It should have a 3.55 rear Chrysler 8.25 reading this table again.  That helps clarify the 3.73 and the 3.55 discrepancy.

 

So this means the 99XJ front axle goes to the 88MJ with it being a 4.0 Manual seeing they should both be 3.07.  The "Facebook special" with the 3.55 non-CAD should go to the 01 XJ, and seeing I have a 2.6v8 originally in the 86MJ I should probably let that go, the non-CAD is stronger anyways...

 

Am I correct?  If so I know the actuator is all mechanical next up is figuring out the mechanics of a CAD dash with a non-CAC axle for the dash.

[howeitsdone]

2 hours ago, ExpatMJGuy said:

use the front axle off the 99 XJ for the 88 MJ?  Then sell or scrap the CAD DANA 30?  I can then use the 2wd axles to keep my parts vehicles rolling for now.  Yeah?

 

Yes. That takes care of drivetrain anyway.

 

The clutch/brake pedal is different in late-models too. 

 

Please don't put the 3.55 D30 on the 01 if the rear is 3.73

[ExpatMJGuy]

2 minutes ago, howeitsdone said:

 

Yes. That takes care of drivetrain anyway.

 

The clutch/brake pedal is different in late-models too. 

 

Please don't put the 3.55 D30 on the 01 if the rear is 3.73

Nope, don't think it's 3.73.  It should be 3.55 I just can't read! 

 

I was just thinking I should go scoop up that axle if it makes sense and it's only $80!

 

Please do tell about the clutch and brake pedal stuff because I haven't gotten that far.  Remember I am disassembling the 99XJ that the AX15 came out of.  If I have to migrate the clutch, brake pedal, master cylinder I'll do it.  Speaking of when I pulled the AX-5 out of the 86 it seemed different than when I pulled the AX-15 from the 99.

 

Right now I'm tracking 2 shopping list

 

01 XJ

- D30 Front Axle  (gonna try to get that tomorrow for $80)

- AW4 4x4 tranny (gotta find this)

- Np232 or 231 Transfer case (gotta find this)

- Shortened Rear drive shaft (will buy online not modify due to possible international shipping and overseas inspections)

- Front drive shaft (will take from 99XJ)

- Tranny cross member (Recycle from old AW4)

- shift linkage (thinking about a Novak conversion kit old linkage was real rusty)

 

88MJ

- D30 Front Axle  (3.07 coming from 99XJ)

- AX15 4x4 tranny  (coming from 99XJ)

- Np231 Transfer case (coming from 99XJ)

- Shortened Rear drive shaft (will buy online not modify due to possible international shipping and overseas inspections)

- Front drive shaft (wondering if I can use 86MJ drive shaft if not buy it online as well)

- Tranny cross member (coming from 99XJ)

- Longer Speedometer Cable (gotta find this)

- Shift Linkage (same Novak conversion kit should do)

 

So outside of that AW4 with transfer case most of the big ticket items are covered.  At least from what I'm tracking.  I could be missing things.

 

[Pete M]

what size tires are you using under the MJ?  just because the factory did it, doesn't mean it's what you want to do.   

[ExpatMJGuy]

18 minutes ago, Pete M said:

what size tires are you using under the MJ?  just because the factory did it, doesn't mean it's what you want to do.   

I’m sticking with the stock tire size until gets to Australia.  Ride heights and tire sizes are strictly regulated there.  Once it’s fully imported and registered I’ll get with the local community and see what I can “get away with!”   It won’t be extreme as what you find here no matter what.
 

XJ will stay at my parents house in the barn till 2026 when it becomes eligible for import.  Also strict rules importing Left hand drive cars.  May have to modify the suspension for import but I’ll have experience by then.  It’s on a 3in lift with 246/75/16 tires.

[howeitsdone]

The pedal assemblies are completely different from early to late models. Fortunately, early model clutch/brake pedals are relatively inexpensive. It's the late-model assemblies that can be pricey since there are a lot less. I would also recommend a new master/slave regardless if you're gonna do the work. The late model MC bolts up differently.

 

What are you looking to do with the 99? Meaning, are you swapping the 88 completely to 97+ or just using driveline?

 

Also, just take the driveshafts to a local shop and have them do the work. Will be much less than ordering online. I don't see why they'd fail an inspection. The 86 front should bolt right up. If you did a minimal lift you wouldn't even have to shorten it on the MJ.

 

Plenty of write-ups on swapping different parts all around this site and Google to help!

[Pete M]

I'd still go with 3.55s.  stock ratios suck. 

[ExpatMJGuy]

2 minutes ago, howeitsdone said:

The pedal assemblies are completely different from early to late models. Fortunately, early model clutch/brake pedals are relatively inexpensive. It's the late-model assemblies that can be pricey since there are a lot less. I would also recommend a new master/slave regardless if you're gonna do the work. The late model MC bolts up differently.

 

What are you looking to do with the 99? Meaning, are you swapping the 88 completely to 97+ or just using driveline?

 

Also, just take the driveshafts to a local shop and have them do the work. Will be much less than ordering online. I don't see why they'd fail an inspection. The 86 front should bolt right up. If you did a minimal lift you wouldn't even have to shorten it on the MJ.

 

Plenty of write-ups on swapping different parts all around this site and Google to help!

Haven’t googled that yet because I just haven’t thought that far out yet.

 

Now it sounds like I’ll be moving the pedal and clutch assemblies.  At least I know I need to start researching that.

 

Right now I’m moving the 97+ driveline.  The 01 was bought with a blown engine and I’m taking that from the 99. I plan to horde the 97+ wire harness from the 99 in the event the engine ever dies, and at that time I’ll do the HO swap over.

 

I would take the axles to a local shop if it wasn’t going through customs and foreign DOT inspections.  I don’t want them to even question the validity of the weld line in the drive shaft.