Modern Vespa

The odometer and speedo stopped working on my et4, the PO had replaced the worm gear, so I was annoyed to see it happen again

I opened up the hole, removed the plug, spacer and worm gear, sure enough, chewed up.

Along with it was a TON of rubber/plastic bits. i spent 20 minutes blowing them out, no idea what they come off of.

When I pear in the ring gear itself is a bit chewed up, so my thoughts are it is silly to replace the work gear since the ring gear will destroy it anyways.

Question is; how hard is it to replace the ring gear in the front wheel? and while I am at it, any other parts I should order for the front wheel... idk bearings? whats common maintanance up there.

i am in canada but have a freind down in the states for a short period so I can still take advantage of cheaper prices

For starters, take out the hub and clean up the ring gear. Piaggio uses an "awful" grease that turns to "gum" over the years. That's usually the reason the worm gear gets chewed up…

Yeah! do you have any info on how to do it

unfortunately, a fairly common failure.

you can sometimes get away with a new gear, but you should fix it right.

and, sadly, fixing it right is a gargantuan pain in the ass.

there's only like 4 parts you need. the bearings should be fine unless you have some crazy high mileage bike or it's lived a life off road.

so, the gear resides in the caliper carrier. but to do it *right* you have to remove the caliper carrier. and this is the classic if you give a mouse a cookie. because to get the caliper carrier off you have to pull the wheel, caliper, the hub and the shock. then you replace those few parts and assembly is the reverse of the whole taking apart and cleaning thing.

so, if you've got room to do the work and some fairly basic tools it's totally doable. the biggest hurdle will be torquing up the hub nut and making sure you've got the right pliers for the circlip to remove the caliper carrier.

other than that, tedious cleaning.

Greasy, does that mean taking the shock off completely, or just dangling from the top bolts? I ask because the nuts on the top shock mounting bolts on my ET4 had me cussing like the sailor I was. To me those nuts were more difficult to get to than the spark plug. Neither job was fun.

Replace the plastic gear it is a very easy job. If it fails again replace it again. Easy job not expensive no need to do anything more. Just one persons opinon have done it on a couple bikes. Have not had to do it twice on any of them.

60% of the time it works every time

Rick, no need to remove the shock completely. just the two Allen head bolts that secure it to the caliper carrier, and then you can swing it out of the way. well, technically, the knuckle assembly swings down and out of the way. but no need to mess with those god forsaken upper bolts.

Maybe ill just replace the small plastic gear every few years