This thread covers a new method for adjusting skipping teeth on FF and/or REW on SONY WM-DD series walkmans. It applies to all units that use a center-gear type mechanism: WM-DD, WM-DDII, WM-DDIII, WM-DD100, WM-DC2, WM-DD30, WM-DD33, WM-D3. The problem is described in the original tutorial found here: https://www.walkman-archive.com/articles/sony-dd-repair-guide_05.html (points 11 and 12). Do note that you need to test the walkman upside down (cassette door facing up) as well as there are situations where FF and REW work fine when unit is operated in the normal position, but will skip teeth when upside down. What is described in the original tutorial is quite hard to do because it involves removing the center gear to properly bend the arm and not risk bending the shaft on which the arm slides. Given this and the fact I prefer to not bend the gear arm at all, I thought of an alternative solution which I have tested for quite a while and works well. On the method described below, you only need to desolder the head wires, tilt the PCB and remove the FF/REW buttons. Instead of bending the gear arm, this method involves sticking a very small piece of cloth-type electrical tape right where the button is pressing. Depending on how much warp there is in the center disc of your particular walkman, you may need 1 or 2 pieces of electrical tape. Start with 1 piece, test and then apply a second piece on top if necessary. When you are satisfied with the result, add 2 small drops of liquid super glue on 2 opposite sides so the tape will remain there. It is obvious that you should clean any grease that was there before and not put grease after you do this repair as it won't be needed anymore.
I have tried your fix above and although it corrected REW noise and grinding, it resulted in both spools spinning.... so in my case, the issue was certainly elsewhere. I believe the chassis may get twisted and that's the cause for some of these issues. That could happen because the device was dropped or during disassembly - it is quite tricky to get the chassis out of the case without any guidance - or perhaps someone was heavy-handed. This may be an explanation why these small tolerances on parts that have no obvious signs of wear seem to go out of spec. If you hold a running chassis in FF or REW that is skipping or noisy and gently twist the chassis, you may find the problem disappears. It's hard to recommend this because it could put something else out of alignment, but I have successfully solved the rewind issue by twisting the chassis. It's a tiny tiny amount, carefully applied. It's like taking your Walkman to a chiropractor. And check the case is straight too! My chassis and case were not noticeably damaged or twisted, it had no side-effect on FF or PLAY or screw hole alignment, it's fractions of a mm of twist. So if all else fails, maybe this helps someone. Stuart.
Both reels spinning after the adjustment means the center disc has excessive up/down wobble. The original gear assembly (center hub, disc, gear) was molded as 1 piece, meaning any misalignment of the disc in the mold didn't matter as the assembly was perfectly centric in that original setup. However, when a new gear is installed any wobble in the disc (usually there is both vertical and horizontal) will show up. In the vast majority of cases the wobble is small enough that won't cause major problems: horizontal wobble can render increased gear noise, while vertical will make the unit skip teeth in FF/REW and requiring this adjusment. In the situation that both reels engage at the same time, first thing to do is install another gear. Found the FixYourAudio CNC gear to work better for this scenario. Many times installing a better gear will fix the problem, requiring no further adjustments or even reverting back to no adjustments. There are cases though when just installing a different gear is not enough. In such cases, you need to add tape and also file the button at the same time, so the adjustment is less than thickness of the tape.
That makes sense. Thanks. If I need to go inside again, I'll pick up a FixYourAudio CNC gear and give that a go!!
Thank you for posting this. My DD33 needed to have extra pressure on the rewind button to keep the RW reel gear and center gear height-aligned. In its normal resting position it would slip a lot. The original gear is not damaged yet. Everything else works perfectly and I doubt this walkman has ever been dropped or abused (the condition is too good) so bending the lever angles was not the most appealing idea. Two squares of cloth tape fixed it right up.
