qscorp

My 915 transmission got stuck in 2nd gear due to several speedometer ring magnets falling out and jamming the sliders. These magnets are held to the ring with a bit of epoxy glue. Is there a better way to secure these magnets to the ring, or some all electronic speedometer to avoid this problem recurring?

Peter Zimmermann

Wow, this is one for the books! Did someone just have this trans apart? I've inspected hundreds of those magnets, some with 300K miles, and have never found a loose one or cracked epoxy. Need to know more!
Pete

qscorp

The tranny had not been apart for at least the ten years (and 70K miles) that I have had it, but what brought this on was some spirited driving in autocross. When the case was opened we found a few broken dog teeth scattered around inside. Also we found that the drain plug had been replaced with a non-magnetic one. I have had the fluid changed 3 times in 70 K miles of use as a daily driver only.

Peter Zimmermann

So it wasn't speedo ring magnets, just dog teeth? As the synchro ring in an '86 or earlier car starts to wear the reduced thickness of friction material means that the synchro/slider can't stop the gear entirely before the dog teeth are engaged. Eventually the dog teeth break off, until the synchro ring pops out of position (the ring of dog teeth hold the synchro ring in place along with a large retainer), which renders the gear inop. Getting stuck in a failed gear is really unusual, the more common problem is that the gear can't be engaged. AutoX or not, I've seen transmissions that were blue inside from lack of oil/heat, and those magnets stayed in their little recesses. I would love to see some pics if you can manage it!
Pete