A good place to send your unit if you don't want to buy gears or it's beyond your abilities:
Ice Cold Auto Air -- Ask for Mike White (VDO authorized repair shop)
Overseas Speedometer -- Rick Borth (Repair shop) Links that you can find very good FAQs on: E39 Headlight Adjuster FAQ (PDF) -- Thank you David Voynow E39 Headlight Adj for Angel Eyes -- Another perspective -- Thanks Trent Cole Matthew's 850 Volvo Cluster R/R FAQ
Brickboard -- Volvo
Kino's Volvo Website -- 850 Cluster R/R FAQ
240 Volvo.com
Rennlist -- Porsche
Clark's Garage -- 924, 944,968 Porsche
911 90-98 odometer FAQ (Courtesy of Brian Smith)
928 Message Board
Porsche 928 Maintenance Tips and Procedures
Handwritten site reviews here
A thread for fixing a BMW or (MB-same thing) unit
Roadfly.com
Home of the First Fives web page
mye28.com
E36 Seat Gear FAQ
The Unofficial BMW Web Page
Removing your 1982-1988 Cluster (BMW 635)
Removing your 1972-1981 instrument cluster (BMW)
Taking apart your 1972-1981 speedometer (BMW)
Car Parts Directory - Parts and Car Stuff for Car Enthusiasts
German Star -- Good source for MB parts at good prices
MB Resources
VW Super Beelte Website
Autohaus AZ Tech Forum
Derek Dorroh's Eagle Premier and Dodge Monaco page
E-mail link: Dave Baumwald's electronic repair.(He fixes lots of different auto electronics)
Different Racing, home of the worlds fastest four door Saturn and S-series technical pages