Hey Guys, my new 6s stepper motor arrived and i dove right into fixing the gauge.
Using what i learned the first time around it was very simple to repair, i opened up the new 6s and removed the gears and windings, and then re-built the lexus motor with the new gears and winding. With very careful assembly i got all 3 gears lined up and engaged before snapping the bottom cover back over all three. In hindsight i realize now i actually lined up my gears incorrectly, i reversed the alignment of the big gear, having the hole on the outside and nub on the inside. Made no difference, probably impacts the spring rate of the needle by adding an extra half turn to the lower fixed coil.
Quick rundown:
1. De-solder stepper motor completely and pop it open exposing internal gears.
2. Repair broken smaller gear with glue (let it dry thoroughly!) or parts from another stepper motor
3. Using top cover with spring assembly sitting flat on something, assemble 3 gears with winding.
4. Carefully lower the bottom cover down over the top making sure the pins line up in the center of the gears
5. Confirm it rotates with the same resistance, and stops correctly turning it both directions
I made a quick youtube video of how i lined up the gears and snapped them together using the old parts and 6s top instead of the lexus top, but the job is the same in the video, just a little easier because the top sits flat. I also included a few photos of how i lined up the gears.
*In the video i have the long shaft/large gear flipped so i can lay the cover flat on the table, and i mix up top from bottom a bunch*
Cant believe i was debating sending my cluster to Tanin! Stepper was $28 on eBay! Now to figure out what they do to increase the brightness of the lights. New lights soldered into the board, or maybe the caps are drifting out of spec causing them to dim? Doubt it with the age, my Marantz sounded fine with 50 year old caps before recapping it.