5-Inch Sky Robot
FDM in Vacuum
Custom Discovery Roof Rack
August, 2012 - Sierra Backpacking
July 22nd, 2012 - Hiking in Santa Barbara
July 15th, 2012 - Valley of Fire
May 5th, 2012 - Afton Canyon
April 28th, 2012 - Devils Playground
Convict Creek Trail
January 2012 - Mustangs
January 3rd, 2012 - Heart Lake
August 7th, 2011 - Kelso Dunes
August 5th, 2011 - Lundy Canyon Hike
August 2011, Mammoth Archery
Birds in the garden
June 4th, 2011 - San Gorgonio
May 29th, 2011 - Sequoia National Forest
April 23rd, 2011 - Living Desert
April 2nd, 2011 - Death Valley
March 8th, 2011 - Mountain Palm Springs
February 13th, 2011 - Iron Smelt
November 13th, 2010 - Mojave
October, 2010 - Mammoth
September, 2010 - Mammoth
September, 2010 - Duck Lake Trail Backpacking
Iron bloom forging
August 28th, 2010 - Mt. San Jacinto
OSM Import: US Designated Wilderness
July 25th, 2010 - Mojave Mustangs
July 17th, 2010 - Mojave Exploration
Bloomery furnace iron smelting
Open Street Map: Mojave Project
June 13th, 2010 - Mojave
June 6th, 2010 - El Cajon Trails
Wolf Mountain Sanctuary
March 28th, 2010 - Salton Sea
March 21st, 2010 - South Main Divide
March 13th, 2010 - Anza Borrego Wildflowers
March 7th, 2010 - CSULB Japanese Garden
February 2010 - Mammoth
Dakota and Asha Celebrate Christmas, 2009
November 21st, 2009 - Mojave Road
November 14th, 2009 - Anza Borrego
Exploring The East Mojave: The Afton Canyon Area
Broken flex plate
Remote Image Serving
Astro/night photography in Inyo National Forest
Wild Mustang Sightings
September 26th, 2009 - Night Photography In Frazier Park
August 15th, 2009 - Catalina dive trip
January 24th, 2009 - Mojave Exploration
July 2008 Mammoth Vacation
President Barack Obama!
April 12th, 2008 - Wildflowers and Landmarks
My Grandfather's Alfa Romeo Spider
March 8th, 2008 - Carrizo Plain
Bridge To Nowhere
October 20th, 2007 - Big Bear Camping
October 22nd, 2007 - Fire
Scottish Highlands, Aug 7th, 2006
Scottish Highlands, Aug 6th, 2006
August 5th, 2007 - Duck Lake Trail
May 26th, 2007 - Kelso Dunes
Culloden Battlefield, Aug 5th, 2006
May 20th, 2006 - Irwindale Renaissance Faire
Edinburgh, Aug 4th, 2006
The Clifs of Moher, Aug 3rd, 2006
The Burren, Aug 2nd, 2006
Bunratty Castle, Aug 1st, 2006
May 5th, 2007 - Mojave
Truck Audio/Data Network
2007 - Master Bath Remodel
The Ring of Kerry, Jul 31st, 2006
Victory in 2006!
Blarney and Killarney, Jul 30th, 2006
Dublin and Cork, Jul 29th, 2006
Dublin, Jul 27th & 28th, 2006
What Can I Do?
April 30th, 2006 - Anza Borrego
New desktop: Intel 805 D
Jan 7th and 14th, 2006 - Hiking
Whiting Ranch Hiking
Digital Photography with Linux
September 5th, 2005 - Living Desert
August 19th, 2005 - Mammoth
Hiking and Photography
July 30th, 2005 - Tucker Wildlife Sanctuary
Death, Fright and Photography
May 14th, 2005 - Red Rock
April 2nd, 2005 - Death Valley
Count Every Vote Act of 2005
Linear Logic ScanGuage
November 6, 2004 - Mojave
Super Tuesday, 2004
Canon A80 Camera
Jul 25, 2004 - Death Valley
May 4th, 2004
Landscaping - My Front Slope
Stump Pullin' Yeeee Haw!
Feb 22nd, 2004
Feb 16th, 2004
PostgreSQL Logfile Analysis
Mountains? Desert? Jan 30th, 2004
Jan 28th, 2004
Ceiling Cargo Basket
Front Bumper Version 2
Land Rover Valve Jobs
The Matrix: Revolutions
Greg Davis CDL Linkage
Mom's Turkey Gravy
Julian Pie Company
The KB1DIG 2-meter Halo Antenna
Gardening is hard!
Aug 13th, 2003
SQL and Perl
Jul 9th, 2003
Jun 17th, 2003
Some People's Comments
Dakota is a silly dog
The Matrix: Reloaded
Chris' Stage Bottle Harness
April 23rd, 2003
DVD Burning Under Linux
My Satellite Phone
My Near-Death Experience
Laser Cannon Revival
Front Bumper, Version 2
KPC 3 Plus and HTX-252
Moving, moving moving...
New new house
In Truck Dr. Pepper
My Favorite Toilet
Late Thoughts: Dr. Pepper Cooler
265/75-R16 Tires on a DII
George W. Bush
Horses Sep 14 2002
August 17th Yukon Dives
My Custom Front Bumper
Bracketless, Renamable Links
Jul 28 2002 Day Trip
Jedi Group, my T1 and money
A Bumperless Discovery!
My Custom Rear Bumper
Vanessa's 24th Birthday
Jun 30th Dive to Long Beach Canyon
PHP/PostgreSQL String Quoting
Tonsillectomy, Uvulaectomy and Turbinite Reduction
240 Watt CO2 Laser Cannon
The Tulsa Rib Company
The quality of hard disks these days
Email notification of articles
Email notification of comments
erikburrows.com source code
Renisance Faire Jun 9, 2002
Computers hate me, and it is mutual.
Star Wars Sucks!
Horses, Jun 1, 2002
Land Rover Mileage
Insomnia, Robin goes evil.
100 Watt Diode Laser Test Firing 1
2001: A Space Odyssey
TDI Deco Class
Horses, Apr 30, 2002
My Truck Batteries
The Zope Bible
100 Watt Diode Laser
The New www.erikburrows.com
Hunter the Kitty
Matts Desert Pics
|Greg Davis CDL Linkage -   2003/10/13||Viewed 101 times this month, last update: 2005/08/31|
|Greg Davis designed a DIY center differential lock for those Land Rover discovery II's made in 2000 and 2001 which still have the locking differential in their transfer cases. The design utlizes 3/8inch socket driver extensions and U-joints, plus a hand-made end piece. He published this design in the Tech section of Discoweb, where I saw it several months ago.|
I really liked the simplicity, elegance, and low cost of the design, and have been thinking about doing it myself for a while. This last weekend, I started the project. I created the first version of my linkage, and test-fit it in my truck.
This required a complete dissasembly of the center console, but I managed to get it in place without having to completely remove the transmission tunnel cover. I did this by threading a wire through the hole, out the path I wanted the linkage to go, and pulling it back up with the wire. Thus, I avoided taking the cover off, and even more importantly, without having to dissasemble the delicate pieces of the main shifter.
Here you can see where the socket driver extension comes up through the transmission tunnel cover. It's held up by a pipe clamp, on top of a washer. Below the washer is a rubber grommet which completely seals out the noise of the engine and transmission.|
That patch in front of the shaft is a cover over the first hole I made, which turned out to be too far forward. It would have interfered with the operation of the high-low shifter. I covered the hole with a piece of galvanized steel sheet, and pop-riveted it in place. Some 'goop' sealant makes it waterproof and quiet.
This is only the test-fit. Now I need to remove it, cut the shaft to put the shifter knob just above the console floor, and paint the welds on the linkage to prevent rusting.
Here is the linkage I made. The key is the 10mm X ~15mm hole at the end, which fits around the flats on the CDL control. I used a spark-plug socket for the end, instead of a seperate joint and socket, just to save cost and complexity. I also cut the socket down do about 3/4 inch. It's got to be as short as possible to clear the fuel lines which run right over the transfer case. This does clear, by about 2 inches, but just to be sure, I rounded all sharp corners.
After sizing the upper shaft, and adding three divits for the set-screws of the knob, I rustolium'ed and oiled it, then with the help of Vanessa, installed it, and replaced the center console. As described in the tech section of Expedition Exchange, everything went together very easily.
And after the installation, the knob works perfectly, actuating the center differential locking mechanism with some, but not too much force. Actually, it's just perfect. It takes too much force to do it by accident, but not so much you need to worry about breaking anything.
Now I need to take it out to the desert for a real trial!
I've been on two good off-road trips with the CDL,
the Borrego and the Mojave. The CDL makes a HUGE difference. When one wheel is off the ground, ETC (electronic traction control) just doesn't cut it, but a locked center diff pulls me up and over.
Alex (2005-12-07): I am thinking about putting this on my 2000 disco but have heard that the traction control will cause considerable damage to the drive shafts and transfer case over time - is this true?
Erik (2005-12-07): A CDL does add additional stresses to the driveline, but the CDL that
you are trying to actuate is exactly the same one as on the D1 models,
since the transfer case is the same model, and actually the D2 prop
shafts and axle shafts are stronger than the D1, so you should be in
However, if you are going to be racing your truck across boulders, you
could still break stuff, but so would any setup.
If you want to discuss this with some pros, (and people who pretend to
be pros, like me) check out www.discoweb.org
Rich L (2006-02-16): go to www.ashcroft-transmissions.co.uk/part_17.html#pa2 which have a full description and parts to do the official Land Rover modification and this site explains how the ETC is compatable with the centre diff and what wires to cut etc. a really excelent website on this subject.
Erik (2006-02-17): Rich, thanks for the link. Yes, that is a very nice alternative to the somewhat hacky project above.
Steve (2006-11-29): This is the best diy job I have seen yet and am going out to the shed to begin manufacturing one now. There's no way I'm parting with $600.00 for a kit just to enable the CDL. Great work.
Erik (2006-12-04): Thanks Steve!
brian (2008-02-25): i know its 2008 and this post is old but do you have any pics of exactly where the CDL control is on the disco 2? thanks for any info....email@example.com
Erik (2008-02-25): Brian, it's in a very hard place to photograph. It's on top of the t-case, up in the transmission tunnel. If you put your hand up and over the front output flange of the t-case, if you have the CDL nipple, it'll feel like a 1/2"-3/4" threaded rod, with a square base.
Will (2010-01-23): There is a pneumatic controlled CDL available from C&M Manufacturing. You can get it through Great Basin Rovers. It is controlled by air like an air locker and it is around $200. I have some pictures if anyone is interested.
Lynx S (2010-01-26): Hey I would like to see some pix and get more info on that air locker kit.
Blake (2010-02-10): Thanks for the design spec's; great job, brilliant actually. Intuitive and functional. Much less to break or fail, and even if it does, you are intimate with the simple design and could fix it in 15 minutes in the hardware store parking lot. I think I'm going to cut a groove so I can use a circlip to maintain the position of the shaft and put a fixed 90-degree in it near the top so the respective CDL status is known at a glance. (fore/aft=un-locked and rotated = locked.) I might also Plasti-Dip/Plasti-Cote the entire linkage once finished for protection and stock appearence. Great idea and execution. Thanks again.
Will (2010-02-21): The web address is cm-mrg.com where you can get the kit. There is a nice video for install and it is quick...like 30 mins to install.
Will (2010-02-21): Correction the the web address for the Pneumatic CDL shifter. cm-mfg.com
Patrick (2016-02-15): I get this thread is ages old, but I was wanting to know if you remembered how long the extensions were. TIA.
Erik (2016-02-15): I don't remember, but from the picture it looks like a 6in and a 10in extension.