Swapping Speedometer Cog

[z_again]

Hi, I have a 77 280z with a 5 speed in it. I assume the car came with a 4 speed and the 5 speed was put into it by the previous owner. My speedometer is off by about 12% (too high as measured with a GPS).

My question is, what is the easiest way to swap the speedometer cog? Can you do it from inside the car through the opening for the gear shifter or do you have to do it from underneath the car?

The reason I ask is that I have the center console pulled right now as I am installing the MSA rear speaker panel kit. If it should be done from the top then now is the time to do it.

Also, my car is getting the typical fumes in the car. When I pulled the center console I found the rubber boot on the shifter had a nice big tear in it. So replacing that now and will see what happens. This is my first Z with a standard, the previous 3 had autos (so my wife could drive them). One thing I will say is that I never had exhaust fume problems with the autos. Any idea on that?

Thanks, Les

[sblake01]

You change the cog from underneath. Beware, the gear lube will spill out when you remove the sleeve so be prepared to catch the lube in something. You'll also have to top up the lube level when you're done. I've never had exhaust fume problems with a stick. The type of transmission has no bearing on that. (no pun intended:))