CJ-7 Projects


Lightforce Lights - H.I.D. High-intensity discharge Upgrade

HEI Ignition System (GM Style) Installed in the AMC 360 V8
Getting rid of gremlins and improving performance

Installing 23,000 Volt Offroad Lights

Autogage Tachometer Installation

 Home Page
 Photo Album
 Product Reviews
 Cool Products
 Tech Section
 Readers Rigs
 4x4 Club Links
 Links Directory
 Shop Offroaders
 Centralia PA
Project CJ-7
Offroaders Guide
to Gearing up
for Offroad

From Basic Equipment to Well Equipped.  An extensive list guide to help you prepare your vehicle for the offroad.


Onboard Air
Converting a York
AC Compressor
to Pump Air

Trailering Safety and Trailer Hitch Information


Off-Road Truck Driving Techniques and Safety

Off-Road Lights
by LightForce Product Review / Installation.
from Off-Road Lights


Jeep Dana 300 TeraLow - 4:1 Gearset for the Dana 300 Transfer Case

AMC V8 Engines
GEN-1 Nash/Hudson/Rambler V-8s (1956-1966) through to the GEN-3 AMC Tall-deck (1970-1991)

Chevy Small-Block V8 Engines
Chevy Small-Block V8 Engines Manufactured by General Motors - Production: 1955?2002

Hemi Engine - All about the Hemi Engine

Ford Engines
4 Cylinder, 6 Cylinder, 8 Cylinder, 10 Cylinder, 12 Cylinder Ford Engines

Ford V8 Engines
8 Cylinder Engines manufactured by Ford

Ford 351 Cleveland V8 Engines
351 cubic inch V8 Engines manufactured by Ford

Chrysler Hemi Engine

AMC V8 hp/Torque, Compression & Bore/Stroke by year

Engine Size Conversion Table
Converting engine displacement from CID, Liters, C.C.

Engine Overheating Basics - 16 Common Causes of an Overheated Engine

Fan Clutch Diagnosis
How to tell if the Fan Clutch in your Cooling System is failing or has failed.

Automotive Gauges & Instrument Functions
Information they display & their importance.


From the
Department of Cheap   Tricks and Useful Tips

Ultra-Cool Hand Throttle for Free!

Jeep V8 Swap Tips

The Exploding Clutch

Radiator Protection using 6 bucks worth of material

Cracked Under Pressure - Fixing a smashed fingernail

A Cheap, effective alternative to undercoating

Home-built Saginaw Gearbox Brace for the cost of lunch!

Ammo Box Storage - Mounting Them for Quick Disconnect

Home-built Serious Skid-Plate protection for the Oil Pan for under 20 bucks!

Ramp Travel Index
RTI / Ramp Travel Index  What it is and how to calculate it, with and without the ramp.




Powertrax No-Slip Traction System
Installation ... or so we thought... make that ...
Detroit Locker Installation


Occasionally you set out to do a project and things don't always go as you planned.  This was one of those such projects where the installation of a Powertrax No-Slip Traction System ended up becoming a DIY Detroit Locker installation.  You might be wondering how that could happen, well, that's exactly what happened.  If you're looking for an installation process of the Powertrax No-Slip Traction System, you'll find that here as well, but the following write-up takes a left turn about halfway down the trail. Read on...

First a little background info...

This CJ-7 is equipped with front and rear Dana 44 axles, the front from a Jeep Wagoneer Hybrid (formerly a Scout Dana 44) and the rear Dana 44 out of a late 70's Scout.  Both axles have open pigs with 3.07 gears.  The plan was to install a Powertrax No-Slip in the rear, run it for a little while, then when funds and time are available, swap in lower gears, drop the Detroit Locker that was up on the shelf into the rear axle and move the Powertrax No-Slip up to the front Dana 44.  Sounded like a good plan.

So we set out one fine Sunday morning to install a Powertrax No-Slip into the rear Dana 44 of a Jeep CJ-7. 



Digging In

It started out as any good axle project might, by loosening lugs of the rear tires before jacking it up.

Then we secured the vehicle on jack stands and blocked the tires.

We removed the differential cover and cracked the seal to let a watery, mocha expresso mix out of the differential.  First sign of trouble ahead?  Maybe but it isn't like we haven't seen that before.  Sort of comes with driving though rocker panel deep creeks and mud holes.  Which is good reason to inspect your gear oil once in a while.

First inspection of the gears and the carrier were fine.  Nothing looked worn or damaged.  So we let it drain and cleared out any crud at the bottom.





Following the Powertrax No-Slip instructions, the passenger side axle will have to be pulled out a few inches, so we removed the passenger wheel and drum brake, then removed the 4 retainer bolts for the passenger side axle shaft located on the inside of the brake backing plate. Then pulled out passenger side axle shaft a few inches.



The Powertrax No-Slip instructions suggested that with some gear ratios you are able to remove the pinion shaft retainer bolt or Roll pin in this case, and then remove the Pinion Shaft without removing the carrier from the axle.  Apparently with some gear ratios the ring gear is not as thick and the pinion shaft will clear the ring gear and slide out.  A 12 penny nail with the point ground flat made a good improvised replacement for the long thin punch, which we didn't have.  With the Roll Pin out, we tried removing the pinion shaft.  It didn't clear the 3.07 ring gear.  The carrier will have to come out.
So we jumped over to the driver side and removed the tire, brake drum, retaining bolts and pulled out the driver side axle a few inches as well.
Removing the Carrier

We marked the Carrier Bearing Caps as left and right, top/bottom prior to removing them.  I used a center punch and punched 1 mark on the driver-side/top and two marks on the passenger-side/top and made a mental / verbal note.  Then we removed the Bearing Caps and set them aside.

Then we proceeded to remove the carrier.  Generally the carrier is a snug fit.  Sometimes very snug.  In most cases we've had to use a series of pry bars, to gently pry the carrier out of the axle housing. Don't pry on the gears unless you are scrapping them.  If you use this method of prying, hang onto the carrier.  They have been known to let go and pop out.  Very tight axle housings might require a spreader, which bolts onto the axle housings diff cover plate bolt holes and spreads the housing open ever so slightly; enough to pull the carrier out.

With a little persuasion from the 18" pry bar and a smaller pry bar, we had the carrier out.


To the Shop Bench

Since the Ring Gear had to be removed, we found that we could grab the carrier in the vice without touching the bearings or spider gears.  This setup good access for use of the breaker bar to back off the ring gear bolts.

With the ring gear removed, we tapped out the pinion shaft.  Funny, those usually slide out.  Seems to be some resistance on this one.

With the pinion shaft out, the Spider Gears and Spider Gear Washer rotated out.
The Spider Gear and thrust Washers that the axles slide into were next to be removed.  The passenger side slide right out.
Driver side Spider Gear and Spider Gear thrust Washer were a different story.  For some reason they would begin to come out but would seize up and not budge.  An old 30 spline axle shaft made a good battering ram to pound out the spider gear.


This is where things got interesting...

Once the Driver-side spider gear was out, we could see why it didn't want to come out.  If you look to where I'm pointing out in the top picture to the right, you'll see metal stuck to the machined surface of the spider gear.  Click the picture for a close up.  That metal came from the carrier in the bottom picture again...  click the picture for a close up.  How that happened, I'm not sure.  I'd guess the axle sat for a long time and had moisture in the axle housing.  The metal to metal seized, then later when it went back into service, it tore the metal from the housing and scored the hell out of the carrier's machined surface where the spider gear rides.  The bottom picture you'll see what the spider gear surface should look like.

What did this mean to the PowerTax No-Slip install?

Look again at the carrier's scored surface.  That's where one side of the PowerTax No-Slip Coupler rides.  The carrier and Coupler are supposed to be close tolerance.  The good side was a close tolerance fit, the scored side was not and it wobbled in the carrier.  Not good.  I think the PowerTrax No-Slip would probably be damaged in a short period of time without a clean engagement of the PowerTrax Coupler and the PowerTrax Driver and Synchro
Ring to the Paddle.  A quick end to a fine 400 dollar lunchbox locker that really should be up front.


So Now What?

This is where the trail takes a left turn.  These were my options:

  • Install it anyway and risk damage to the PowerTrax No-Slip.
  • Pull the carrier out of a Scout Dana 44 and try to shim and use that.
  • Put the original open carrier back together with the damaged parts and play with it for a while until I have funds and a time window to install the Detroit locker sitting up on the shelf.
  • Get it to the shop and do the gears and the Detroit Locker within the next 3 weeks, just in time for the "OK Auto 4x4 Tour 2006" ... or ...
  • We try to put the Detroit in Ourselves!
With "OK Auto 4x4 Tour 2006" only a few short weeks away and the thought of another weekend offroad with an open carrier, we decided to try out skills (read luck) at installing the Detroit Locker and getting the gears meshed right.

If you want to continue reading about how to install a PowerTrax No-Slip, follow this link.

Installing the Detroit Locker

The first thing we had to do was pull the old wheel bearings off.  We were going to reuse them and the shims so using a big gear puller, we successfully pulled the bearings off both sides without tearing up the shims (too much).  We kept them separate to identify which went on the left and which went on the right as well as the shims, left and right.

We also got of the micrometer and compared the two carriers, the open and the Detroit Locker, to figure about where the ring gear bolting surface was on both.  We were trying to guess at about where the shims might have to be moved to get the ring and pinion gears to mesh as well as possible.

The two carriers were close in measurements from the driver-side end to the ring gear bolting surface (close enough) so our first attempt at putting it in was to put the shims back where the were on the open carrier and tap the bearings on using a large socket, tapping on the inner bearing race.  Smearing some grease on the inside of the bearing races helped them go on easier.

We then bolted on the ring gear to the book specified 55 lbs of torque.

Since we lacked any real measuring devices, we found that the Detroit was too wide to get back into the axle housing.  So back to the bench to remove about 2/100ths.  We decided on removing a 2/100ths shim from the side that seemed to be the side that should get the ring gear about where it was in the open carrier.  Nothing technical, just plan old backyard mechanic "saboutrite".  A second time getting the carrier in the axle housing and it was a snug fit and the backlash seemed to be about what we would expect it to be on a professionally setup axle, judging by past pro installations we had done for us. 

We bolted in the bearing caps to the book specified 60 lbs of torque and smeared some grease on the ring gear to get a pattern.  We rolled the drive shaft forward to roll the gears through the grease. A close examination of the grease, then a run upstairs to reference this document to see what the pattern looked like on the charts.  We both agreed that it looked good. Close enough to put it back together and take it for a test run.



Reassembly Stage

We cleaned up the axle housing seal surface with a razor and some break cleaner.  The axle bearings were also clean up and greased even though the wheel bearings are lubricated by the gear oil.  We also cleaned the outer seal surfaces and put a little silicone sealant on the outer axle seals to ensure a good seal.


The axles were slid into the Detroit and the retaining plate re-bolted to the brake backing plate.  The brake drums were re-installed and the tires put back on, hand tightened.


A liberal coating of gasket silicone was placed on the axle housing and the cover plate bolted down.  We broke for lunch to allow the silicone to set up a little before pumping in the gear oil.  After about 45 minute we pumped in some gear oil and plugged it up.  We lowered the Jeep and tightened the wheel lugs.  A quick test of the locker was to jack up one tire as it was being backed out to see the other grab.  It did.  Nice.

First Run Out

Our first run out was around the neighborhood.  The Detroit was quiet, yet noticeable.  I've had experience with a locker on the road so I knew what to expect.  Throttle in a turn will push the vehicle towards straight ahead.  Shifting through the gears will cause the short wheel based CJ-7 to jerk one way or the other a little.  Knowing it was going to happen, made it easier to predict and compensated for.  The gears were quite, no odd sounds. After a short run, when we got back, we felt for any heat build up of the axle housing and that was minimal.  Seems fine so far.

2nd Run Out ... Offroad

The following weekend I took the Jeep over to a friends house for a little backyard (38 acres worth) wheeling through mud and trails.  Through some low, swampy areas of the property, it was very noticeable the Detroit locker was back there powering the Interco Super Swamper SSRs.  With minimal effort, the Jeep climbed through some very sloppy mud.  Its good to finally have a Locker in the Project CJ-7. 


Final Thoughts

First, the gears are temporary.  3.07 will be 3.73 soon.  With a T-18A transmission and its 6.32:1 first gear and the Jeep in 4 low, the crawl ratio is not as bad as it might be without the T-18.  A 6.32:1 first gear helps compensate for the 3.07 gears nicely.  When time allows, the gears will be swapped and the PowerTrax will be installed up front at that time.

Even though we didn't plan to install the Detroit Locker ourselves it worked out in the end.  I have little concern about wearing out the gears due to a slightly less than perfect shimming of the gears.  Mainly because the Jeep sees very few road miles, most is offroad and that amounts to very few miles in a years time.  Secondly the gears are coming out soon anyway and a pro will install the new gears at that time.  Overall ... very pleased.  Can't wait to hit the trails of Rausch Creek in a few weeks.




Offroad Tire Info
Tire Terminology
Wheel Terminology
How to Pick the Right
Tires for your Truck
Truck Tire Info
Tires - What Hits What Fits
All Terrain  Mud Terrain
Tire Reviews & Info
Mud Terrain MT Tire Reviews
All Terrain AT Tire Reviews
Super Swamper Bogger
Super Swamper SSR
Super Swamper SX
Super Swamper Vortrac
Interco IROK TSL
Super Swamper LTB
Super Swamper TSL
Super Swamper TSL Radial
Super Swamper Narrow
Interco SS-M16 Swamper
Thornbird TSl Radial
Thornbird TSl Bias
Thornbird TSL
Parnelli Jone Dirt Grip
BFGoodrich Krawler
BFGoodrich MT T/A KM
BFGoodrich MT T/A KM2
BFGoodrich AT TA KO
BFGoodrich Mud King XT
Bridgestone Dueler MT
Cooper Discoverer ST
Cooper Discoverer STT
Cooper Discoverer ST/C
Firestone Destination MT
General Grabber MT
General Grabber AT2
Green Diamond Icelander
Ground Hawg Mud Tire
Hankook Dynapro MT
Hankook Dynamic MT RT01
Hercules Terra Trac MT
Hercules Trail Digger MT
Kelly-Springfield Safari DTR
Kelly-Springfield Safari MSR
Kumho Road Venture MT
Kumho Road Venture KL71
Kumho Road Venture AT
Dick Cepek Mud Country
Dick Cepek F-C II
Dick Cepek Fun Country II
Dick Cepek Fun Country Nylon
Dick Cepek Fun Country Kevlar
Mastercraft Courser MT
Mastercraft Courser HTR
Mastercraft Courser HTR Plus
Maxxis BigHorn Radial
Maxxis Creepy Crawler
Maxxis Trepador
Maxxis Buckshot Mudder
Maxxis MA-SW
Maxxis M-8080 Mudzilla
Maxxis MT-754 Buckshot
Maxxis MT-753 Bravo
Maxxis MA-751 Bravo
Maxxis MA-S2 Marauder II
Maxxis MA-S1 Marauder
Maxxis MT-762 BigHorn
Nitto Mud Grappler
Nitto Dune Grappler
Nokian Vatiiva MT
Pit Bull Rocker Extreme
Pit Bull Maddog
Pit Bull Growler
Goodyear Wrangler MT/R
Pro Comp Xterrain
Pro Comp All Terrain
Pro Comp Mud Terrain
Pro Comp Xtreme AT
Pro Comp Xtreme MT
Toyo Open Country MT
TrXus Mud Terrain
TrXus STS All Terrain
Mickey Thompson MTZ
Mickey Thompson MTX
Mickey Thompson Baja Claw
Mickey Thompson Baja Crusher
Competition Claw
Dunlop Mud Rover
Yokohama Geolandar

Latest trips Offroad
... trail reports with the Project CJ-7
click here.

Sounds System, Raised the Rear Seat
Storage below and a great place to mount 6x9 Speakers for Great Bass ... In a Jeep!

York AC Compressor Conversion.  What used to pump Freon, now pumps compressed air to the front and rear bumpers.  125 psi,  2 gallons of storage, air fittings at the bumpers, enough CFM to power air tools!.  Click Here for more  Details


Dick Cepek's 2008 F-250 Super Duty Project Vehicle ? Project CRUSHER

Warn X8000i
Winch Installation

ARB Air Locker Install
Jeep Wide Track Axles Swap

Mud Tire Reviews

Building a Garage?
Need a Garage Plan?

Reader's Rigs and Seriously Stucks!


Jeep Trans Swap Info
T-18A Transmission Rebuild & Short Shaft Conversion