Had the same problem
I had the same problem, I managed to fix it without removing the dials. I started disassembling the actual speedo from behind, removing the cover for the drive cog (where the cable attaches) and then removing the screw gear. When this was done I discovered that the first cog on the odometer (fraction of miles) was slipping when it had to roll from 9 to 10 (It gets loaded by needing to turn the subsequent number at this point.) My first attempt at repair was to squish the cog tighter onto its shaft with a pair of needle nose pliers, this work for 99.9km at which point it stopped again. My final solution was to drill a 1/16th inch hole between the teeth of the cog right through to the shaft. I then dropped in some thin cyanoacrylate glue (get it from a modle store, or try crazy glue) the thin glue seeps between tyhe cog nd the shaft thus making it stop slipping.
Mine is an 83 so not identical but I hope that this helps.
Almost mint 1983 230E eurospec.
Honda civic for those not so mint moments.