speedometer calibrating

[69projectKAOS]

i wasn't sure where to post this, but i was wondering how you calibrate a speedometer on a 69 camaro. i have a th350 if that helps. the speedometer says that im doing like 90 when im actually doing about 50-55mph. thanks-Dom

[CarPlayLB]

Go here

http://700r4.com/speedoCalc/speedocalc.shtml

this is real easy! I believe the gears are the same for the 700r4 as the TH350...good luck!

[130fe]

Here is another website http://www.tciauto.com/Products/Techinfo/speedo_gears.asp You can find out the parts numbers for the correct ones when you have to change them. I always found them cheaper at the chevy dealer than through some of the online retailers. If you have to change the drive gear (always get them mixed up name wise- the one on the trans tail shaft), Pretty easy to do:
1. Jack the car up
2. remove driveshaft
3. remove 4 bolts holding tailshaft to tranny (have a small drip pan when you remove it). Not alot of fluid but some will come out.
4. remove and replace that particular gear and reverse steps.
Be sure to get another "square o-ring" for the tailshaft housing from the dealership while you are there.

The other one (the one behind the speedo cable) is easy to get to. Remove speedo cable and the bolt and retainer. Most of the time, I feel it is easier to remove the tailshaft and see what you have and start from scratch. That way you are not doing this a couple of times trying to get your speedo working right. They are different colors but depending on how long they have been in trans fluid you might not be able to tell the right color. Hope this helps.