Hello Everyone,

I know it's been a while since I've posted and I've been real busy at the new job and racing a hobby stock car has taken up pretty much all my time this summer. Now that the racing season is over I've parked my truck in the garage and started tearing it apart to find some oil leaks and take the mid-ship tank down to replace the sending unit.

In order to find the oil leak I had to take the transmission out again and thought it would be a great time to replace the speedometer drive gear since I've never been able to get the speedo to read correctly no matter which driven gear I've put on it (I've used the 16-20 tooth gears). The speedo has always been reading about 15mph slow at 55mph (speedo reads between 39-40mph). I've replaced the cable a couple of times and the speedo itself twice so I don't think the issue is there and that leaves me the drive gear. It is fairly worn down in the center and I don't think I'm getting all the teeth engaged.

That brings me to my question. Where can I find a replacement drive gear and should I stay with the 6-tooth green gear or move up to a 7 or 8 tooth gear?

Here are the specs:

245/75r16 tires
Borg-Warner T-18 transmission
16-tooth Driven gear
4.11 final drive

According to the calculator, with a 6-tooth drive gear I should be using a 16-tooth driven gear for the speedometer to read accurately.

If anyone has a place that I can order a new drive gear I would be very appreciative.

Thanks guys.

 

Welcome back, Jeremy! We've missed you. Do you need a part # for the gear? Oh wait, you can do that yourself. As for a recommendation on how many teeth, what would be the impetus to change?

 

That's what I was wondering. Should I change? I did check and the rear tires that I have on the truck right now are about 1.5" taller than the front tires. I'm switching them out with another set of rears that are closer to the front tires as far as diameter goes. That should get me closer to the correct reading on the speedo.

So, hopefully if I change the tire diameter of the rear wheels then I should be able to stay with the 6-tooth and 16-tooth combination.

I wasn't looking for a part number per se, but a good location where I could order one would be helpful as I haven't found a place online that has them and the parts stores obviously don't carry them.

Any suggestions as Ed retired over a year ago and the site has been turned off?

 

Sorry, I don't have any suggestions. Maybe Chris will?

 

Looking up speedometer gears in the catalog is a HUGE pain in the azz. Search the archives of this forum, I've seen places mentioned where these things were bought.

Here's a place I have bookmarked:

Speedometer Gear, Speedometer Gears, Ford, GM, Dodge 700R4

 

I think he's looking for the gear inside the transmission and a place to order one from. IIRC, he has the catalog.

 

Actually, I don't have the catalog, but I was able to find the part number I was looking for on one of the older posts thanks to Number Dummy. It is DOTZ-17285-A. After I had that I was able to find it on Amazon (it's amazing what you can find there) for around $42.

Now I just need to order it and put everything back together after I get the leaky oil pan gaskets redone.

 

Gee. They have a Ford speedo gear for a tranny that was made 30 years ago in stock, but not the label tape I need for a label maker that is still being sold? I just got off a chat session with a lady from India looking for it. But, I found it with two others at $16 for the part and $15 for the shipping. I'm not willing to pay that much for it, so will have to suffer with the while label for a while.

 

chart from frpp .the driven gear numbers are the regular short style .any for dealer can order it


Google Image Result for http://i59.photobucket.com/albums/g303/AdderMk2/speedogearchart.jpg

 

Thanks 86 but I have 5 of those already ranging from 16 to 20-tooth. I need the other gear. The one that is in the transmission. I found them thanks to Number Dummy posting the part number in an older thread.