I replaced my speedo cable the other day because it had melted against the exhaust and was no longer turning the speedo dial. On pulling the plastic drive gear out of the transmission, I found it to be a bit mangled! The teeth were pretty damaged, so I cleaned them up by shaving off the broken bits, and refitted it (finding a new gear at short notice is not an option here in England). Before I order a new gear, would I be right in saying that if this gear is damaged, then so, probably, is the other plastic gear attached to the gearbox output shaft (it's a toploader)? Is this a big job to replace? Do I need to take the trans out and take the tail housing off? or can it be done some other way? Thanks for any advice you can give. David
Get a flashight (torch?) and look in the hole where the speedo gear goes in. It seems to me that the drive gear in the tranny is metal. It is a sleeve that fits over the output shaft of the tranny... it has threads cut into it (like threads on a bolt) I have replaced chewed up speedo gears with no problems (no tranny-removal).... good luck. jimbo
The drive gear is metal. Usually they don't go bad but its not a huge job to replace if it is bad. You can do it with trans still in car. Tim
That's great news! I'll order the 'driven' gear for the end of the cable and let you know how I get on. Many thanks for your help with this. David
Hi, The most common mistake when replacing the plastic driven gear is that people put in the wrong gear, left instead of right and vice versa. The reason your gear was mangled in the first place is probably just that. 4-speeds have the hole on the right side of the transmission and need a left (L) gear and auto/3-speed have the hole on the left side of the transmission and need a right (R) gear. I seriously doubt that your drive gear is faulty. To make an exact calculation of which driven gear you need you just use the following program on the internet: Automotive Programs by Bowling & Grippo. You need to know how many treads your drive gear has like normally six for a hipo top-loader, tire diameter, rear end ratio and 1:1 in last gear. This means your speedometer will be right on the money as well. Good luck and let us know the results. Texas Swede
