I want to add CDL to my '02, so after doing a bunch of research I decided to rebuild a 2004 case. Primary goal is to gain CDL, but I also decided to fit 1.41 high-gears and an improved HD cross pin. 1.41 is the perfect ratio for stock diffs and 32" tires. The HD cross pin will prevent the differential from blowing up in the event of excessive free-wheel spin.

I may actually fit an Ashcroft ATB instead, which is an alternative to the HD cross pin. This depends on how worn my differential is. If its too worn, I'll probably go with the ATB for $500 instead of a new diff for $1,000.

Resources Used
• RAVE Manual. Section on repair and overhau
• LT230T overhaul manual
• Land Rover Toolbox Video Series

Improvements
• Add CDL to my '02
• Regear from 1.22 to 1.41 high to fix uphill *******
◦ New intermediate gear and input gear is necessary for this
• Fit HD cross pin to differential
• New Timken bearings, races and seals

Tools
• Sockets, ratchet, spanners, the basic set of tools
• Impact gun is very helpful for flange nuts, differential nut
• Differential nut socket (from Ashcroft)
• Pin punch set
◦ Straight, tapered, and an extra long set (8")
• 3 jaw puller. I think I used the smallest one… 3"
• 20 ton press
◦ Various sized adapters to help. 3/4" socket set, ball joint kit, etc
• Bearing race and seal driver set
• Plastic chisels
• Copper hammer
• Sledgehammer
• Deadblow hammer
• Magnetic screwdriver
• 30mm socket
• Fish scale
• Calipers
• Micrometer
• Feeler gauge
• Blocks of wood
◦ 2x2, 2x4, and 4x4's in 1 foot lengths
• Heavy duty snap ring pliers. 8"

Do I need to regear? Use the calculator: Ashcroft Transmissions - Ratio Calculator

Part 1: Basic Teardown of major components


Part 2: Detailed teardown
• Differential
• Front housing, rear housing, main casing


Part 3: Inspection
Part 4-?: Assembly

Videos will be uploaded as I work my way through the rebuild

 

Love the video!

I would love to find out where the white connectors for the two 2004-specific CDL sensor switches get connected when you install the new 2004 transfer case. My 2003 Disco came with a 2004 transfer case which was installed by an independent repair shop. However, the shop did not install diff lock sensors & harness. Therefore, my dash lamp for CDL-engaged does not work at this time.

 

Thanks. I believe they plug into this adapter:



However I don't recall seeing 4 of those black connectors (2 for each switch) in the factory harness... I only remember two... so I'm not entirely sure yet on that one. Might have to splice them in parallel?

 

I did some checking on Rave. I hope I am intepreting this correctly....

My Rave shows two types of transfer cases for the Disco-2:

- up to 03 model year
- from 03 model year

According to Rave (see page 1 and page-2 on attached), the diff lock sensor switch for the "up to 03 model year" transfer case has a two-prong type as shown in page-1 on the attached. I believe the two black connectors go into these two prongs. I believe the harness in post #3 may be for the earlier CDL version of the Disco-2 transfer case.

I also mistakenly bought this same harness thinking it would work for my 2004 transfer case

Page-3 of the attached shows the 2004 transfer case. The two diff lock switches are termed in RAVE as the "diff lock FRONT warning switch" and "diff lock REAR warning switch". If I am assuming correctly, one switch will monitor a locked CDL position. The other switch will monitor an unlocked CDL position. Each switch sends a respective signal to the CDL-locked and CDL-unlocked dash lamps.

 

No, the switches are in parallel for the '04 case:



So if either switch is depressed, the diff lock light will illuminate.

What I don't know at the moment is what connectors my '02 disco has. If I remember correctly, it has only 2 single-lead black plugs.

There are two switches, each switch as a 2-lead plug. The adapter I posted earlier will plug into this, and convert it to 2 separate single-lead plugs. So using 2 adapters, the result is 4 single-lead black plugs that need to be hooked up to the ABS computer.

 

Cool, thanks for the clarification.

I also need to open up my center console and peek into the top of my transfer case is see what connectors I have on my 2003.

 

Neat video!

...but why bump up the high range ratio to 1.41:1??

Because if you have an uphill problem, that's what Low range is for, right?!

And if low range can't do it, then low range in Reverse should conquer anything, yes?!

 

Not sure if you are serious or not, but I'll answer anyway. I can't climb highway grades very well. Can't do above 50-55mph without revving the engine to 4k+ rpm in 2nd gear. The tranny will be in 3rd gear at best, but often jumping between 2nd and 3rd all the time. The 32" tires means the RPM is way too low for a given speed. 2700 rpm @ 70mph is ideal... I'm at around 2318. Bumping the gears to 1.41 brings the RPM up to 2699... perfect!

I could regear the diffs instead to get a better low range too, but I don't want to do any work on the diffs at this time. In 1-2 years I might be interested to do lockers and 34" tires, which will warrant a regear at the diff

 

Ah, it's a highway speed thing to regear. I was thinking offroad.

 

Ahh I get it now.

Yeah... there are not any options to regear the low range for the transfer case.. only high range.