VSS Gear (Page 1/1)
842m4SE JUL 08, 01:05 PM
Hi all, so my 84 Fiero's speedo hasn't been working, so I took out the VSS to try to diagnose the problem. I'm not sure whether taking it out dropped it in or it had previously fallen out, but in any case that gear is missing and I'm guessing is in the transmission.
I'm going to try to fish it out later today by draining the transmission so I can see the thing, but is it possible to have driven the car without issues with the gear having fallen out into the transmission?
And also, where is a source I can find a VSS gear now? The Fiero Store was my first choice and I ordered from them, but apparently their supplier isn't making then anymore and they don't have any in stock. Just wondering where I can find a rare part like that intact.
Xenoblast JUL 08, 03:17 PM
The VSS gear is plastic so it shouldnt do any MAJOR damage to the transmission. Still, dont drive the car with that in there. Look in ebay or facebook marketplace for parts fieros and ask to buy the VSS, its not a commonly broken part so people usually dont take them.

You could buy one of those small cameras that people use to look into the cylinders to look in the transmission aswell, I think they are pretty cheap.

One test you could do is try and spin the sensor shaft with a drill, and see if the tachometer responds. If it does, that probably means the gear was never attached.

[This message has been edited by Xenoblast (edited 07-08-2021).]

fierofool JUL 08, 04:39 PM
The VSS doesn't affect the tach. Only the speedometer and odometer. I've tested them as suggested by clamping the shaft into a power drill and turning the ignition on.

I dropped a gear in an 85 4-speed and the car ran like crap because the vehicle speed didn't agree with the throttle position sensor input and other inputs. It may be that you raked the gear off when you retracted the VSS. Very easily and commonly done. If you did, it may very well be lying just beneath the VSS port. Let me know if you need either the VSS or gear, or both.

When the gear came off, I got a very loud bang and jolt, and not only did my gear come off, but the shaft broke as well. A trans shop disassembled it, found pieces of the gear but never found the metal shaft. Never had any problems from the transmission, though.
842m4SE JUL 08, 09:28 PM

quote
Originally posted by fierofool:

The VSS doesn't affect the tach. Only the speedometer and odometer. I've tested them as suggested by clamping the shaft into a power drill and turning the ignition on.

I dropped a gear in an 85 4-speed and the car ran like crap because the vehicle speed didn't agree with the throttle position sensor input and other inputs. It may be that you raked the gear off when you retracted the VSS. Very easily and commonly done. If you did, it may very well be lying just beneath the VSS port. Let me know if you need either the VSS or gear, or both.

When the gear came off, I got a very loud bang and jolt, and not only did my gear come off, but the shaft broke as well. A trans shop disassembled it, found pieces of the gear but never found the metal shaft. Never had any problems from the transmission, though.



It's looking like I'll need the gear, can't find it in the transmission at all.
I checked by raising the car and it didn't float towards the entrance either, and checking the speedometer by spinning the end with it connected actually did work, it sounds like the gear was damaged or had fallen off somehow. VSS fine.
Would you have one that would work for an 84 4 speed?
fierofool JUL 08, 09:42 PM
I do. There were several, depending on final drive, tire size, etc. The ones I have may not be the exact one you require, but it will work with any manual transmission. Priority Mail postage is about $9, so take that into consideration and pm an offer with your address.