Just purchased this vehicle, didn't notice until I'd driven 50 miles that speedometer jumping around. Believe problem is small gear inside transmission that supplies signal to speed sensor. Can buy the gear for $40. Is this a user servicable installation or do I need to go to shop to drop transmission? Tks

 

If I'm not on the right page, please delete. Will someone please help locate a speedometer driven gear for my sister? I have been searching for two weeks now for the driven gear (18) tooth without success. I thank you in advance. Herb