Hello, I have a GOOD question. I have an 84' Olds cutlass, It originally came with 14" rallye wheels(they are still on), 307 engine with 200 metric tranny..(engine, tranny and carb are CCC controlled)

I've swapped out the engine and tranny from the original to a 77' Olds 350 engine and a 77'TH 350 tranny..the speedometer is WAY off. I was told to get a matching set of speedometer gears..Does anyone know what I need or can refer me to someone who does?

Fred Franklin

 

Hello Fred
Here's a speedometer gear for sale on ebay. This one has 37 teeth, you can get different ones with different numbers of teeth. I've never changed one so someone who has will have to speak up. I think... you unbolt the fitting where the speedometer cable attaches to the transmission and that this gear is right in there.

http://cgi.ebay.com/ebaymotors/NOS-1...item1c063b2b75

But to get the correct gear you'll need to know what gear ratio your rear end is, and not the wheel size so much as the height of the tire. For every one revolution of your tire this gear needs to make a specific number of revolutions. Unless... the gear from your 200 metric will fit your TH350. I have no idea if it does, but if so then all you would need to do is pull the one out of the Metric transmission and put it in the TH350. If not, I wonder if you can pull the metric one out and measure the diameter of the gear and count the teeth, then figure out what you would need for the TH350 gear to match that.

Maybe this makes sense and will help you, and maybe it won't! It's getting about bedtime for this old guy so hopefully others can add to this thread and help you figure it out.

 

You might, and I stress MIGHT, be able to take the gears from the old trans, but I'm not sure if they are the same on the 350 as the 200. Either way you should be able to get the correct tooth count from the old gears and order up a new drive and driven gear to correct your issue.
Check this site out.
http://www.transmissioncenter.net/sp...____va.htm#350

 

Something like this:

http://www.transmissioncenter.net/sp...____va.htm#350

 

Ummm.....Joe that is the same link I posted yesterday.

 

Or you can try this:

http://www.transmissioncenter.net/sp...____va.htm#350

(Ok, ok. Sorry. But if it is good enough for Joe............)

 

DOH! (sound of hand smacking forehead)