shaodome

iTrader: (3)

So I've been hunting down the dead speedo problem in my 1992 SC300 5spd (W58) for a few months now. I broke out the oscilloscope this weekend and found I had NO signal at all coming from the speed sensor itself, despite it being a new piece direct from Toyota.

So as a test, I hooked the speed sensor to a drill and manually spun it and received a signal. This signal also now caused the speedo in the gauge cluster to move, thus confirming the cluster and the wiring are fine. The problem is now mechanical.

Upon installing the new speed sensor, I had to reuse the old stock plastic gear and shaft from the original piece. It also appears that the transmission was rebuilt at some point due to the RTV seen on the trans case. Has anybody seen the plastic gear get worn to the point where it no longer makes contact with the screw gear in the trans? I'm trying to find a replacement plastic gear (very difficult it seems) and if that doesn't work that means internally something is wrong with the W58 trans.

Have any board members here experienced this issue and do you happen to know where I can find a replacement plastic gear?

Thanks!

shaodome

iTrader: (3)

Well...I ordered the plastic piece from Elmhurst Toyota on Supra Forums for a whopping $18. Hopefully that will fix the issue...

boobstar

did it work?

JspecSC3

iTrader: (4)

Do you have pictures of what the plastic gear looks like? I might be experiencing the same problem. Thanks in advance.

shaodome

iTrader: (3)

nope no pictures, but its like a $15 part, so even if you do replace it, you won't be out a ton of money. Another way to test to make sure the sensor itself is fine...

Just pop out the sensor and attach the gear side to a drill. Turn the key on and spin the sensor, your speedo should move.