What I'm working on now: Axle Swap and Shock Shifters

[lupinsea]

Today's update: Got the wiring installed and the pump mounted.

The TJs have an "accessory tray" under the
master cylinder. It's not big, maybe ~9"
almost square. But it's a handy flat place to
mount all sorts of things under the hood
and is quite useful. Four bolts and 2
minutes and it's out.

Then I put a piece of paper on the bottom
of the air pump an used a pencil to make
a rubbing. Laid the paper in a good spot
on the accessory tray and center-punched
where the screw holes are.




The pump attached to the accessory tray.




Tray and pump re-installed under the master
cylinder. The lower grommet is where I'll
fish a couple of the wires through the firewall.




It was super easy accessing the PDC
(Power Distribution Center) under the
hood. Four clips and it could be removed
from it's bracket. 5 more clips and the
bottom cover came off.




This is the PDC and the empty module on
the right is where I'll pop in the new setup.




First....get the blank module out. Using
a slim screw drive, the tabs are released
and the module is pushed out the through
the bottom.




Then to install the new module I wired
up to the pump / switch harness.




Next step is to remove the relays, turn
the module block over, and release the
two yellow tabs holding the yellow collar
piece on. The module block won't fit in
the slot with the yellow collar on.




Then, slid the new module block in until
it snaps into place. Snap the yellow collar
piece on from the top, plug the relays
back in. Done. Oh, and route the harness
to the back of the PDC, snap the bottom
cover on, then snap the PDC back into place
on it's bracket. Attach the power lead.

It's notable that there's an extra relay, extra
empty slot, and some extra wire leads I didn't
remove from the module. . . . so I have
room for future expansion for other
electrical goodies.




Inside, the interior wiring harness was
installed, zip tied into place, the switches
snapped into the bezel, and all the dash
panels reinstalled. It took longer to wrap
the harness in electrical tape than it did
to reassemble the dash.





Locker switch and indicator light. . . neat and tidy install.

Oh, and the good news, when I flipped the safety switch and the dash switch the air pump turned on. I also put a jumper wire in the axle sensor plug to test the indicator light.... it works, too. So the whole electrical system works.

I gotta say, it's sweet how easy it is to pull the dash panels and access the guts of the Jeep. While by design or by accident it's something I appreciate working on this and is another indication of user friendly these are to work on.



.

[lupinsea]

#$*%&@)& )@( !@)(* )(@* )(!@*#$!@#$* ......

Part of this project involves swapping the pinion yoke to a different type. I figured I'd install the axle and then break off the pinion nut and swap yokes. No dice.

After getting the axle all hooked up the night before (brake lines, suspension links, etc.) I had a tough time getting the nut loose. My DeWalt electric impact wrench wouldn't budge it. Then I borrowed a neighbor's pneumatic impact wrench, also no dice. After he came up to look over what I was doing he suggested I pull the axle out again and use a big cheater bar.

Ungh...

So, I remove the axle yet again.

Originally I fabricated my own spanner wrench to hold the yoke still while I cranked on it with the impact wrenches. I ended up putting so much force on the nut with the cheater bar that the steel the wrench was made of tore apart. Then I welded the pieces together and that did it.

Oof.

It was a late night swapping the new pinion on (once the nut was loose it didn't take long) and then re-installing the axle back under the Jeep. These things aren't light and I'm guessing the housing weighs north of 250 lb.

The welded spanner wrench and 3 ft
long cheater bar with a 1" drive socket.




The two yokes side-by-side. The old yoke
on the left and the new yoke on the right.
The Rubicon axles used a "stronger" yoke
and u-joints through out the drive shafts.
But it's a bit overkill and unnecessarily long.

[lupinsea]

Well, it's all finished. . .

The last bit was a push to get the Jeep ready to go camping July 2nd-3rd.

The axle swap was largely wrapped up early in the evening on July 1st with me needing to tie up some loose end torqueing down the suspension bolts, settling the suspension, and some other bits and pieces. The last thing to do was swap out the front axle shafts (worn shafts and u-joints) and I started on that at about 11:30pm. It's not complicated but as I was disassembling the front axle I noticed that I had no front brake pads left. Ok, no problem. . . figuring I'll do the axle swap and just get new pads in the morning. . . pop them in and then pack up the Jeep for the weekend.

Not so fast. Got the new pads but had difficulty fitting the caliper and pads back over the rotors despite squishing the caliper piston back. Long story short, the piston seal must have come unseated and gotten jambed in the back of the caliper. I ended up having to install new calipers as well and do an last minute brake bleed.

We still went camping but it took until mid after noon to get out of town.




Last of the pix:

The new axle installed under the Jeep.




This shows how much the lower shock mount had been moved outboard on the axle.

I've been driving the Jeep a little more than normal since the swap (especially since I had the ZHP in the shop again for half a week). To me the difference in handling and ride quality is noticeable. With the factory set up there was always a little tail wiggle from the rear of the Jeep. That's completely gone now and the whole rig feels better planted and controlled. . . more like a normal vehicle, which in this case is a good thing. Incidentally, the newest generation of Wranglers (the JKs) have this exact same shock set up and orientation.

Also, the locker operation is very slick. Nice, quiet, quick, and operates as advertised with little fuss.

The lower gearing I now have (4.10 gears vs. my old 3.73's) was a subtle improvement over the previous gearing. It's not the deep gearing many Jeepers prefer that gives a lot of twist. But the Jeep now feels right. Good acceleration, no sense of lugging or extra effort to get going, and the Jeep can easily (if not rapidly) accelerate up steep grades but not too high of an RPM so there is still comfortable cruising. In short, a well balanced gear ratio both for the tire size I have and will be moving to. If anything I'm finding I have to watch my speed a bit more than I used to.

[kognito]

How do/did you correct the speedometer after diff change??

reprogram ECM? or is there a plastic gear to change??

or just guestimating speed??

I guess you could just see with a GPS if the speed readout changed much

[lupinsea]

I have a plastic speedo gear sitting on my workbench at home that has the appropriate gear tooth count. There is a speedo gear thingy on the tail housing of the transfer case. Takes maybe 5-10 min to swap speedo gears and its easy to access. . . but I just ran out of time getting everything done for the camping trip last weekend and haven't bothered to change it yet. But I have it.

There are maybe 20 different speedo gears for these transfer cases depending on tire size and gear ratio.

So. . . the speedo correction is pending.

There's a nice thread on Jeepforum called "Take-a-speedo-leave-a-speedo" where fellow Jeepers can exchange their speedo gears. Rules are that you can request a speedo gear for free, shipper pays postage (~$3.50) but then you have to post up your speedo gear for whoever wants it and then cover shipping to send it that person someone else. The thread was started in 2008 and there have been a few hundred exchanges by now. Sure beats paying the $50-80 cost of a new speedo gear.

If one did want to buy a new speedo gear this chart is very handy, just look up tire and gear ratio, then add the two numbers in the chart to the end of part number "520676 _ _" for the proper speedo gear. For example, for 33" tires and the 4.11 gear ratio I would need a 36 tooth gear or part number 52067636, which is what's sitting on my work bench.

[lupinsea]

Last piece of the puzzle was finished last night.

Got the speedo gear installed. Very straight forward: Remove single bolt and clamp holding down the speedo sensor housing. Pull housing out and pop off speedo gear. Re-install and rotate sensor housing so that the gear tooth number range (embossed on exterior of sensor housing) and pointing down. Then reinstall clamp and bolt and retorque.

It took longer to clean the grime off from around the speedo sensor housing and wash my hands afterward then it did to change the speedometer gear.

Well, now that is done and the whole project is complete.

[3LOU5]

Wow. I just noticed how open and vulnerable your gas tank is.

Have you ever punctured it while taking on a challenging trail?

[lupinsea]

Nope.... what you're seeing is the factory "HD" skid plate. It's about 1/8" thick steel that has been formed and corrugated. It actually holds up plenty well for general trail use as I've landed on it countless times dropping off of ledges and scraping it over rocks and logs.

The actual plastic fuel tank sits inside that.

And, uh, I've already modified the stock skid to pick up some extra ground clearance.

Apparently, when you install a 1" body lift it leaves an extra 1" of space to tuck the gas tank up a bit higher. Just drop it down, cut the mounting flanges, overlap and re-weld them about 1" lower and reinstall the whole shebang. Takes 2-3 hours start to finish. And it goes much easier if you're working with an empty tank.

Before and after....



1. Remove the gas cap bezel.



2. Remove the electrical to the pump, the f
uel line and evap line



3. Remove the plastic tank from the skid
bucket.... cut mounting flanges off



4. Overlap the mounting flanges 1" from the
top edge of the cuts, clamp together



5. Re-weld the flanges back on, re-install skid
plate and gas tank.