changing speedo gears

[ocbaud]

tell me exactly what i need to do and what parts i'll need to change the gears in my speedo to read accuratly.

with the 2.73 gears and 255/70/15's the speedo was dead on.

what gears will i need to get in order to change it to read correctly with 3.73's and 27" tall tires? and would a chevy dealer carry these gears? what all will i need to do to change it

[ocbaud]

so lets see...

i would need a drive gear of 15 teeth
and
a driven gear of 43 teeth

i guess when i swap out my rearend, since i'll already ahve the drive shaft disconnected, i'll do this too.

[mckpaul]

swervin's old site http://www.73-87.com/ has an article with pics that should help a lot. I just went through all that, replaced the 700r4 in my truck with one from a Suburban, had to change the gears. Well, actually, ended up not having to change the drive gear, turned out that it was the same. My stock combo was 18 teeth on the drive gear, 36 teeth on the driven gear, so I just put the 36 in the tranny that's in the truck now. I went ahead and pulled the tailshaft cover to verify the gear in there was the right one, and changed the rear seal while I had it off.

Like you, my rear end is 2.73 and the tires I'm running are 255/70/15's. When you get into it, I'd like to know how many teeth your current driven gear has that makes it dead on. Thinking of changing my 36 to a 35 tooth. The 36 tooth is white (but probably looks orange or red from soaking up the dye in the fluid) and the 35 tooth is orange.

Also, I have a green 42 tooth gear that came out of the Suburban tranny. Gears are cheap, but if you want it to play with to compare it to a 43 or whatever, you can have it, I'll mail it to you. There again, it's from a 700r4, not sure what tranny you're messing with or if the speedo gears are the same.

[loblazer]

Go to www.tciauto.com and they have all the info and calculations you need to pick the right gears for your trans.

Doug