For the
rear axle upgrade, I took another different path.
AMC20 rear axles were notoriously weak with a couple fatal flaws that aren't really correctable in the overall design scheme of things. It's easy enough to change out splined axle shafts with one-piece flanged Chromolly or 1540 steel shafts but that won't correct the biggest fault that AMC had with their model 20 rear end. The
casting and axle tubes are just too small and thin to withstand any abuse, thus they flex and in extreme cases, can even break the carrier housing. In 2006 I had gone to the dunes to play and got a little too much "air" under the ole' CJ. When I landed it tweaked the axle tubes and cracked the carrier housing where the tubes go into the housing all the way to the cover flange. The axle started leaking immediately so I silicone sealed it up to get home, A 3 hour drive down coast highway to home. On that drive, the rear axle started to make noises so I knew the internals were on their last gasp. I parked the CJ until I could get back to fixing it.
Looking around, I noticed that the
"Cash for Clunkers" government buy-back program was in full swing and people were trading in really nice cars or SUV's for a huge payout towards a "new" supposedly more efficient replacement vehicle. I took a look around the salvage yards and discovered that in order to qualify for this
GOVERNMENT CHEESE program, it came with a catch. The dealers taking these beauties in were required to pour silica sand into the crankcase and run the motor, therefore destroying the engine and it's resale value! This was to make sure these vehicles motors wouldn't return to the highways and byways of American public roads. An ABSOLUTE GOVERNMENT CRIME as far as a gearhead like myself is concerned!!!!
This caused certain vehicle populations to EXPLODE in salvage yards across the country. I noticed for one that the
Ford Explorers were one of the highest turn-ins for this program ever and as a result, salvage yards were selling parts from them at
"giveaway" prices. I picked up a Ford Sterling 8.8 axle with disc brakes complete including parts of the suspension still attached for a mere
$100! The vehicle it was removed from was a 2001 Explorer XLT 4x4 with only 87K on the clock! It was turned in for the
GOVERNMENT CHEESE bonus of up to $4,000 more on trade towards a new vehcile.
Enough on the back story:
I had the
passenger (long side) shaft and housing shortened to use two drivers side shafts, bought a spare drivers side shaft and
re-drilled them to 5x5.5 bolt pattern. I bought ARP 3.25" long speed-nut style lug studs and installed them in the new holes.
Stitch welded with low hydrogen-Nickel rod the axle tubes to the carrier housing and re-configured the hard brake lines to fit the
CJ7 .
Grinding off the spring perches and re-centering them to the CJ7 springs, I now have an axle that is not only stronger than the
AMC20 but stronger and beefier than the
Dana 44 's that cost a whole lot more for a CJ wide-track! Shortening the rear axle had three major effects:
1. It pretty much
centered the axle's drive line with the
Transfer Case output.
2. it is so close to the factory wide-track width,
(only 5/8" wider over all) not noticeable.
3. 4-Wheel disc brakes!
Using
Rubicon TJ Wrangler rear brake cables adapted to fit the parking brake on the CJ and re-using all the hard lines that came with the Ford 8.8, I was able to make the brake system look and work factory-like ONLY BETTER NOW! It's modern, has larger diameter axle tubes that won't bend anywhere near as easy as the spindly excuse on the old
AMC20 . It has a Detroit Locker I installed and came with matching 4.10 gears to the front 4.10's in the GM Camper Special
Dana 44 . What more could anybody want!
To top it all off, I installed a heavy cast iron cover both front & rear to protect my new investments. The shock mounts are attached to the spring plates now and I installed mini skids to protect the lower eyes. It would be super easy to do a SOA and have totally protected axle U bolts with nothing to get hung up on if I were to want. I like the SUA in the rear with the longer shocks, it adds a great deal to side-hill stability at the Jeeps height and totally prevents axle wrap from damaging the driveshaft U joints.
Last hints:
Get under a
turbo T-Bird or an Aerostar van to snag the flange/U joint adapter so you can use a flange style pinion yolk that comes with the Ford 8.8 in junkyards. It's usually under
$5 at the time you get your axle. Especially if you leave it attached to the 8.8 at checkout.
What you are looking for if you want a Ford 8.8 in your CJ:
For disc brakes, look for a 1995-2001 2 or 4 door. Has 31 spline 1.32" dia. shafts.
For drums, look for a 1991-1994, they are usually even cheaper than the disc brake units.
Don't forget to make sure it has all the hard brake lines and hoses with it.
Look for common gearing of 3.55, 3.73 & 4.10's everywhere.
There are a few that are even higher, (numerically lower below 3.55).
If you want to install a lunchbox locker, look for an "open" carrer model.
If you want to rebuild the Ford Limited slip unit, find one with it inside.
You cannot add a lunchbox "aussie" etc. to a Limited slip carrier so be sure what you want.
Prices have risen a little in the intervening 15 years since I did this but they are still many times well under $200-250 for the complete axle. Especially on 1/2 price or sale days.
Bottom line:
Hard to get this much beef for so cheap that needs very little work to fit in a CJ wide-track. If you were to stick with 60" wide "narrow track" SJ full size
Dana 44 up front, you could just leave the Ford 8.8 AS-IS, without narrowing it and it would be close enough.
The
next closest cheap options to this besides finding a pull
Dana 44 out of a 1986
CJ7 or
CJ8 would be to snag the
Dana 44 out of a late 80's XJ Cherokee or go with the
8.25 that has disc brakes from a 2002-2007 Liberty. It will not have as many locker or axle shaft options as the
Dana 44 or 8.8 has due to
popularity with both the
XJ/TJ crowd and the Mustang crowd.
RR
