First Lift Build and need gearing info/advise please.

[dkroll]

I have many questions on proper and/or functioning gearing options for this project. The following specs are what I have right now;

 

 

1988 Comanche short bed

4.0L engine rebuilt 40 over bore.

1996 AX15 5 speed tranny with 272 transfer case (needing a shift mode fork), or swap out with something different.

Advance Adapters  SYE output kit for transfer case (this is how I found out the bad shift mode fork).

8 inch Rusty's long arm front lift.

SOA on rear end (levels out real nice).

Front end axle= Dana 44 G2 electric locker, geared 373.

Rear end axle= 1996 Ford Explorer 8.8 (with some kind of electrical switch (??)). geared at 373.

15 inch rims with 35 inch Tires.

 

Some of the questions I have are;

1).  I don't exactly plan on taking it out crawling, I choose 373 gears for better higher speeds (highway), and it will be a "Mall Crawler" for starters right now. Will these gears be okay for now?  

 

2).  I am new at this....Someone told me that if the front ratio is the same as the rear, I could expect about 40 minutes of fun off road until my transfer case shelled out.  Is that true? Why? What can I do to have it perform as a "stock" 4x4 Cherokee/Comanche when off road on lite to moderate terrain?

 

3). With a limited budget, what do I need to do (if anything) to get this baby to be fine on a road trip or be a daily driver with NO gearing issues to pop up in any short time frame?

 

4). Where in the hell do I find (on the cheap side), a "shift mode Fork" for this transfer case (i.e.. numbers on it are; 5209 7695  89   93 3  272.?

 

5).  Will this tranny with the transfer case match up with my older tranny mount?  The Rusty's long arm was for a XJ, but the sales guy swore it would fit under my Comanche, But now I have a 1996 tranny and transfer case out of a wrangler, Are they compatible??? (Craigslist find).??

 

6).  What pinion angle to I set my rear 8.8 at?  Is it specific to just the rear end with using the SYE, or is there a more complicated approach with the set-up I have? I have heard both and don't know....leaning towards just this individual axle and set and weld perches in.......?

 

7). Are there any other issues I need to be looking at?  I am open for any suggestions/ comments and/or concerns, just need some good direction to put this thing together and get it on/ off the road.

 

I am sorry if any of these questions are silly, but I am in a learning curve to get this Comanche looking/performing nice like my 2wd does. I have always loved these trucks and have had much fun and worry-free days when it was time to turn the key and move on down the road.

 

 

Thank you for any info!!! 

Doug

 

[Eagle]

1988 Comanche short bed

4.0L engine rebuilt 40 over bore.

1996 AX15 5 speed tranny with 272 transfer case (needing a shift mode fork), or swap out with something different.

Advance Adapters  SYE output kit for transfer case (this is how I found out the bad shift mode fork).

8 inch Rusty's long arm front lift.

SOA on rear end (levels out real nice).

Front end axle= Dana 44 G2 electric locker, geared 373.

Rear end axle= 1996 Ford Explorer 8.8 (with some kind of electrical switch (??)). geared at 373.

15 inch rims with 35 inch Tires.

 

Some of the questions I have are;

1).  I don't exactly plan on taking it out crawling, I choose 373 gears for better higher speeds (highway), and it will be a "Mall Crawler" for starters right now. Will these gears be okay for now?

They'll be "okay," but they won't be great. For reference, 3.73 gears with 31" tires is exactly the same ratio as a factory automatic with 3.54 gears on stock tires. My guess is that at highway speeds you will be cruising at well below the torque peak of the engine, and that your gas mileage will suck in 5th gear. Here: http://comancheclub.com/topic/27178-tire-size-gear-ratio-rpm/  

 

2).  I am new at this....Someone told me that if the front ratio is the same as the rear, I could expect about 40 minutes of fun off road until my transfer case shelled out.  Is that true? Why? What can I do to have it perform as a "stock" 4x4 Cherokee/Comanche when off road on lite to moderate terrain?

You need to stop listening to "somebody," because "somebody" doesn't have a clue. You WANT the ratios of the two axles to match. It's when they DON'T match that you start grenading transfer cases.

 

3). With a limited budget, what do I need to do (if anything) to get this baby to be fine on a road trip or be a daily driver with NO gearing issues to pop up in any short time frame?

Finish what you already have in progress and then don't touch anything for at least six months.

 

4). Where in the hell do I find (on the cheap side), a "shift mode Fork" for this transfer case (i.e.. numbers on it are; 5209 7695  89   93 3  272.?

You call a shop that specializes in transmissions and transfer cases. But ... at the top of your post you wrote that you have a "272" transfer case. Never heard of it. What is it and what's it out of? XJs and MJs (except for 1986 and older) used either a 231 or a 242.

 

5).  Will this tranny with the transfer case match up with my older tranny mount?  The Rusty's long arm was for a XJ, but the sales guy swore it would fit under my Comanche, But now I have a 1996 tranny and transfer case out of a wrangler, Are they compatible??? (Craigslist find).??

Don't see why it won't work. My '88 MJ has a YJ Wrangler AX-15 and transfer case in it.

 

6).  What pinion angle to I set my rear 8.8 at?  Is it specific to just the rear end with using the SYE, or is there a more complicated approach with the set-up I have? I have heard both and don't know....leaning towards just this individual axle and set and weld perches in.......?

With a slip yoke eliminator, you will need a new drive shaft with the slip joint in the shaft. You have two options for the new shaft: (a) You can have it made with the upper/forward end set up with a double Cardan joint, like the front driveshaft. If you do that, the rear pinion angle should be zero (pinion parallel to drive shaft) with the truck sitting at curb weight. If you prefer to use a single u-joint on each end (like stock), the pinion angle should be set parallel to the angle of the transfer case output shaft. All of which means you have to measure your truck. Nobody here can tell you what angle to use.

 

7). Are there any other issues I need to be looking at?  I am open for any suggestions/ comments and/or concerns, just need some good direction to put this thing together and get it on/ off the road.

How are you getting the rear tires to clear the frame? 12" tires are a problem with a Jeep axle, and the Ford is narrower. Are you running spacers, or wheels with a large offset?

 

I am sorry if any of these questions are silly, but I am in a learning curve to get this Comanche looking/performing nice like my 2wd does. I have always loved these trucks and have had much fun and worry-free days when it was time to turn the key and move on down the road.

I'll be blunt -- if you wanted worry-free, you should have left it stock. The more you modify, the more opportunities you create for problems.

[dkroll]

Thank you for that info.  Yes, I was wrong, it is a NP231 transfer case out of a '96 wrangler.  I am using wheels with an offset.  I will continue searching for the shift mode fork.

[87Warrior]

From the Factory parts listings for the 231:

 

FORK, Mode Shift Transfer Case

P/N 4741237 w/Transfer Case 52097888, 52097890, 52097526, 52097696, 52098358, 52098360, 52098487, 52098540, 52098661, 52097696, 52098526, 52098316

P/N 4741237 w/Transfer Case 2098318,52098319,52098471,52098473,52098480,
52098469,52099120, 52099212

P/N 4761227 w/Transfer Case 52097894, 52097695, 52097893, 52098361, 52098362, 52098563

P/N 4338920 w/Transfer Case 53008210

 

I hope this helps.

 

FYI - That 'electrical switch' at the top of the Ford housing is simply the Ford speed sensor. Most folks just leave it in place vs trying to plug the hole.

 

I'd love to check out your truck sometime. It sounds like quite the rig.