Probably you best bet would be to use LEDs in place of the standard bulb. Going higher in wattage will only heat the optics and melt things.

I know a member on here used them in his 124 with good results.

I believe the bulbs are 194 Wedge Bulbs..
Search Results For "194 wedge" | LED Replacement Bulbs for Cars | 12v | Super Bright LEDs

One word of caution on this approach...I had a customer send in a cluster to be re-worked. He bought a kit of gears off a website and it turned out they were just a hair undersized for the system and one of the gears missed meshing. So as long as you get the proper diameters, you should be all set.

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Cruise Control not working? Send me PM or email (jamesdean59@gmail.com). I might be able to help out.
Check here for compatibility, diagnostics, and availability!

(4/11/2020: Hi Everyone! I am still taking orders and replying to emails/PMs/etc, I appreciate your patience in these crazy times. Stay safe and healthy!)


82 300SD 145k
89 420SEL 210k
89 560SEL 118k
90 300SE 262k RIP 5/25/2010
90 560SEL 154k
91 300D 2.5 Turbo. 241k
93 190E 3.0 235k
93 300E 195k

[QUOTE=JamesDean;3342303One word of caution on this approach...I had a customer send in a cluster to be re-worked. He bought a kit of gears off a website and it turned out they were just a hair undersized for the system and one of the gears missed meshing. So as long as you get the proper diameters, you should be all set.[/QUOTE]

I'm using the SWAG method of estimating because my gears are shot. The speedo & odometer drive mechanism has been specific to the rear end ratio on other cars I've been involved with. It would be helpful to have a compiled list of rear end ratios and odometer gear specs.

I plan on installing and comparing GPS speed with the speedometer after it's repaired.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

OK. Thanks.

Thought I would post this here. It's a very good write-up on fixing a bad 123 odometer with lots of photos.

How to Repair Your Broken Odometer

just keep in mind, the 126 has a different fault issue than the 123's do.

the 123's have an aluminum gear that slips on the shaft, and the shaft needs to be knurled or the gear needs to be glued back to the shaft (I STRONGLY recommend the knurling method)

the 126's are electic motor driven, and there are super thin gears that just disintegrate, and need to be replaced.

the 126's cluster is easier to remove. I've never needed any tools, you just grab the top, and the adjuster knobs, and pull it out.

the 123 is a bit tougher, with the speedo and oil pressure lines needing to be disconnected first. so pushing out from the rear is the best.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!