Thought I would post some information / thoughts that I gathered this weekend whilst swapping my XJ steering box for a Durango box. I also chose to swap in a tie rod from a v8 ZJ, and add a power steering cooler to the mix at the same time. So here are my thoughts / findings:
First the steering box swap. The new box I pulled out of a 99 Dodge Durango with the v8 engine. A 1998 Durango will work also as long as it's the non-plow version. Wow what a pain that was - the durango not only has a crossmember directly beneath the box and drag linkage, but it also has 2 pitman arms, one on the box, the other attached to the frame, making it a huge pain to separate where the joints (no room for a puller to fit). Eventually got it off after a bunch of banging and swearing. I also grabbed a tie rod from a V8 Grand Cherokee ZJ. Actually i'm joking, i grabbed the tie rod, sway bar, and drag link because i wanted to compare them all to the stock XJ components.
Durango Box on the left (freshly cleaned and painted), stock XJ box on the right.
The Durango box has exactly the same mounting and length, but as the picture may/may not show, the Durango cylinder is much bigger than the XJ's - almost 1/4" bigger. In this case bigger = stronger, thus the upgrade.
Onto the linkages/sway bar.
After removing my stock XJ linkages, i compared them to the ZJ linkages i pulled from the yard.
First the sway bay - i thought this would be exactly the same, but it wasn't. The ZJ bar is shaped completely different, and although the mounting points are the same, the bar ends that attach to the links are angled very differently. On a stock height XJ, this means the mounting points are much higher when that bar is rotated to the same place. Perhaps this bar can be used on a lifted XJ instead of extending the links? Someone want to test this out?
So pictures: ZJ is the black one on top, XJ is a rusty one on the bottom
Exactly the same size bar as a 1995 XJ Sport:
Next the drag link - mostly exactly the same, the only difference seemed to be the angle of the attachment point for the steering stabilizer...not a big deal. XJ top, ZJ bottom
Exactly the same size bar:
Onto the REAL upgrade, the tie rod. The ZJ rod is 1/8" thicker, and SOLID. Compared to the XJ's tie rod it was huge and much beefier. The proof is in the pictures: XJ top, ZJ Bottom:
ZJ bar is 1/8" larger diameter:
So now that we have that settled, my components are set: ZJ Tie Rod, XJ drag link, XJ sway bar, Durango Steering Box. All in a fresh coat of paint and new poly joint boots. Mmmmm yummy.
Now to attach the new, stronger steering box to the frame, i decided to reinforce the mounting point a bit, and at the same time get rid of the crappy stock aluminium spacer. C-ROK sells an awesome steering box reinforcement plate system. I opted for just the inner plate since my wheeling isn't too extreme yet, and future plans for a off-road bumper will occupy the spot used by the outer plate. The inner plate comes with 3 frame sleeves also, which get inserted before the bolts are put though. It also utilizes the very strong stock tow point bolt, adding an extra bolt. All this means that any load going through the steering box off-road will be distributed better along the frame rather than just at the bolt holes.
As you can see this thing is pure beef - 3/16 plate
Now the bigger dimensions of the durango box require the use of some additional spacers - i found 2 washers to be the perfect amount. You're going to need 3 new 7/16"-14, 4" long grade 8 bolts to get enough length, and also a 9/16" bolt for the tow point hole. Here you can see it in place:
I at one point had found a writeup, i believe on Stu Olsen's Jeep site, where he had installed a power steering cooler. I though why not, it's a great idea, and certainly can't hurt to cool the fluid better when you're offroad at low engine speed. So when i was at the junk yard i also picked up a tranny cooler off a random truck - any will work as long as it's a good size to fit. I put mine inside the radiator support beam, and using some new transmission line, spliced it in line with the low pressure return for the steering box.
So here's the finished product. I think it looks pretty damn sexy.
So now the effects. I've driven it a few times over the past couple days, and my impression is wonderful. Overall the steering feels tighter, and i can now turn corners using two fingers. The ratio seems tighter also, it only takes 1/2 turn of the wheel to turn a sharp 90* onto a side road, and the truck doesn't seem to want to drift as much side to side. Overall a great mod that I can't wait to test out off-road. It's a lot of work, but well worth it.