Author Topic: Prepping for the big drivetrain swap (Read 9365 times)

Nightpath · « **on:** August 28, 2014, 04:54:34 PM »

Howdy all,

I'm preparing for my big drivetrain swap, but before I order a bunch of parts I just need to make sure that I have the essentials.

I am swapping the current 258 and old drivetrain out for a newer low km 4.0L / AW4/ NP231 from my donor Jeep. This is the list of parts that I have to order to complete it that I know of :

- Fuel pump - in tank for an XJ (current one on XJ has a broken tube)
- Engine mounts - Jeep CJ I heard fits good
- Oil pressure switch
- Oil pan gasket for 4.0L - (probably go with cork)

Here is my plan :

I plan on keeping the 4.0L as stock as possible, this means the fan system as well and A/C pump. I may look for an electric fan (Ford Lincoln?). I can always move the battery tray or cut it and weld in a box for the battery. I *may* swap to the ZJ waterpump/fan combo if there is absolutely no way to fit the stock XJ parts in, but I'm trying to stay on a budget and buying a new waterpump, fan and belts really isn't in it right now.

Using the XJ crossmember, will have to be lowered and slid back a tad. This will be fab work. Then there's the miscellaneous prep work, like grinding down the rib on the block, and cutting the power steering pump bracket. XJ fuel pump. Slide that sucker in, most of the lines are new metal ones so it should be good to go. My mechanic buddy is a brake/fuel line specialist so it's no worry.

With the AW4+231, does the front driveshaft have to be lengthened? Can I use the XJ front or rear driveshaft on the Eagle?

Swapping over the 258 oil pan to the 242. Besides replacing the gasket is there anything else I should purchase for this?

I want to swap the Eagle steering box out for the one from my XJ, as well as the power steering pump. Is this doable?

Also swapping my defunct rear axle out for a Dana 35 with 3.55 (and swapping the shock mounts around), and swapping my front axle out for a SX/4 Dana 30 with 3.55. The bearings appear to be good in the D30 I picked up, but the seal for the driveshaft is leaky...will any Dana 30 seal fit this?

Along with this, I'll be snagging some other things that need attention. Ujoints, a few other gaskets and seals, etc.

Is there anything missing from my list? I'll update is as I go along, try to keep it pertinent for anyone wanting to do this swap as well. When I actually start it I'll be taking photos.

eaglefreek · « **Reply #1 on:** August 28, 2014, 06:25:00 PM »

I'll answer the ones that I know. I had the Eagle front drive shaft made longer and used a 2wd Grand Cherokee rear shaft and had it shortened. You can have the 4x4 XJ one made longer, but it costs more to make it longer. Steering box is a bolt in.

Nightpath · « **Reply #2 on:** August 29, 2014, 07:05:47 AM »

I'll have to measure my Eagle driveshaft. I know the one on my old xj is a hair above 30 inches.

eaglefreek · « **Reply #3 on:** August 29, 2014, 09:10:08 AM »

Quote from: Nightpath on August 29, 2014, 07:05:47 AM

I'll have to measure my Eagle driveshaft. I know the one on my old xj is a hair above 30 inches.

If you're talking about the rear, the Eagle shaft has a slip built into it where as the NP242 has a slip yoke requiring a solid shaft. If you were to install a SYE(slip yoke eliminator) you might be able to use the Eagle shaft without modification.

Nightpath · « **Reply #4 on:** August 29, 2014, 10:06:44 AM »

My XJ has the 231, looks quite similar to the Eagle's driveshaft.

eaglefreek · « **Reply #5 on:** August 29, 2014, 12:05:31 PM »

Does the your 231 transfer case have fixed rear yoke or slip yoke? If fixed, at some point a SYE was installed.

Nightpath · « **Reply #6 on:** August 29, 2014, 03:23:11 PM »

Not there atm...trying to remember from looking underneath. How can I tell?

carnuck · « **Reply #7 on:** August 30, 2014, 12:16:33 AM »

If the shaft slips into the tcase instead of bolting on (with a slip joint in the middle of the shaft) then it's a stock XJ/whichever 231

carnuck · « **Reply #8 on:** August 30, 2014, 12:26:29 AM »

Top two are fixed yoke and the bottom one is slip yoke (TJ style) Earlier ones slide into the trans like a car driveshaft.

http://www.novak-adapt.com/images/pics/transfer_case_parts/231_driveshaft_angle_comparison.jpg

Nightpath · « **Reply #9 on:** August 31, 2014, 08:48:46 AM »

I'll have to check that out when I get back to it but I think it looks like the sye.

Besides what I mentioned above to purchase, is there anything else I should be considering?

Nightpath · « **Reply #10 on:** September 01, 2014, 12:27:36 PM »

OK...what do I need to look for in regards to fitment?

I know that the rib needs to be ground off, and the power steering bracket needs a bit of modifying.

What is this I hear about an intake not clearing the brake booster?

carnuck · « **Reply #11 on:** September 01, 2014, 05:23:07 PM »

Pre '98 HO intake will hit the booster. Renix will just barely clear.

Nightpath · « **Reply #12 on:** September 01, 2014, 06:19:38 PM »

I take it that I'll have to bang a good old dent in it for it to clear will I?

Nightpath · « **Reply #13 on:** September 04, 2014, 02:03:30 PM »

Should I look for a intake from a later XJ, or just tap a dent into mine so it'll clear?

eaglefreek · « **Reply #14 on:** September 04, 2014, 04:37:29 PM »

I could have sworn I saw at least two Eagles posted here with 91-98 style intakes and they cleared the booster. I wouldn't be putting a dent in a brake booster.

mudkicker715 · « **Reply #15 on:** September 04, 2014, 07:01:44 PM »

A dent could compromise the structure. Vacuum is a lot of force that could destroy it.

Nightpath · « **Reply #16 on:** September 04, 2014, 08:57:12 PM »

Not the booster, I'd tap one into the intake. But I think you're right. I'll find out in a few weeks anyways.

eaglefreek · « **Reply #17 on:** September 04, 2014, 10:31:20 PM »

Quote from: Nightpath on September 04, 2014, 08:57:12 PM

Not the booster, I'd tap one into the intake. But I think you're right. I'll find out in a few weeks anyways.

You're not putting a dent in the intake. It would just crack. I guess you could grind it, however it's not very thick. I searched for quite some time and could not find the pics I saw a couple years ago of the pre 99 manifold installed.

eaglefreek · « **Reply #18 on:** September 04, 2014, 11:26:52 PM »

Finally found one.

carnuck · « **Reply #19 on:** September 05, 2014, 12:19:30 AM »

Maybe it just the 2wd AMCs with that problem. I know it didn't clear in my '84 J10, even with an XJ booster swapped on!

Nightpath · « **Reply #20 on:** September 05, 2014, 09:46:55 AM »

It would be nice if I had hydroboost in it, engine would fit by that without a problem.

I'll find out in a couple of weeks how it fits. We have a action plan set.

Gut the XJ of all it's goodies.
Gut the Eagle of all it's baddies.

Slide the Jeep goodies into the Eagle. Fab what needs fabbin, do all the wiring.

Profit.

I suspect it'll take a good 25-30 hours in the end.

captspillane · « **Reply #21 on:** September 11, 2014, 05:06:59 PM »

Quote from: carnuck on September 05, 2014, 12:19:30 AM

Maybe it just the 2wd AMCs with that problem. I know it didn't clear in my '84 J10, even with an XJ booster swapped on!

The engine would be at Centerline in a Spirit. On an Eagle it is offset an inch or so to the passenger side. That is why it fits without a problem in an Eagle.

Nightpath · « **Reply #22 on:** October 12, 2014, 07:00:39 PM »

OK, in preppin I've been eyeing up the NP242 to replace the NP231 that's currently on the XJ drivetrain.

Any pros or cons, fitment wise, of the 231 vs 242? Remember the 4.0/AW4 are being installed as well.

carnuck · « **Reply #23 on:** October 19, 2014, 01:28:55 AM »

Spline count changed from 21 to 23 on the AW4s 08/90. HOs are 23 spline like the Eagle, but the XJ ones are deeper by 15/16" than the Eagle ones so an AW4 with Eagle tcase would need a 1" spacer ring.