I have been searching for a long time now, and I cannot find any real help with my new problems.
I regeared my 3.08 to a 4.10 and now my speedo is wacked out.
I thought I would just flash the computer at the dealership, but no.
No programer, nothing obvious to add, what am I missing?
Can anyone give some advice or direction?
I'm getting desperate.

 

I didn't see what year vehicle you are talking about. Now the older ones (pre '99, I think) had to be changed by changing the little plastic gear in the vehicle speed sensor assembly. The newer ones are done by flashing the pcm. Now the dealer is only able to flash your pcm with if that particular gear ratio setup and tire size was originally offered stock. Yours may not have been. Now the dealer should have told you this, if they knew anything at all.

In my situation I went from 3.55s to 4.10s in my old '98. Well Ford didn't have a plastic gear with proper number of teeth. I stopped at the local speed shop and got the proper gear -- brand new MOPAR gear that has worked fine now for years.

Mike Troyer can easily get your speedo right with a custom flash and you can get his tuning at the same time. So, the right flashing is available, but very likely not from the dealer. Give Mike a call. He can answer your questions far better than I. I called Mike in my situation and he was able to tell me exactly how many teeth I needed on my replacement gear.

best of luck, you've got the hard part done, now the speedo fix is very doable

enb

 

My appologies, I now see your truck is a '98 like mine. So the fix is done thru the little plastic gear change not reflashing. In my case the dealer was absolutely no help at all. Now I don't know your tire size, but I think the gear I used had either 21 or 23 teeth on it. From my experience Ford didn't have it. Do you have a manual or auto trans? For the manual the vss (vehicle speed sensor) is located near the back of the tranny on the driver's side. It has, I think, two small bolts holding it in. Remove those and pull assembly out. Gear is held on by a small metal clip. Just change gears and put back together. Now you may not be able to get spot on accuarate as your individual setup (gears and tires) may not have a gear with the exact proper number of gears.

These gears are about $5, if memory serves. Try a local speed shop or even your Mopar parts counter. I would pull that vss first to see what that little gear looks like. I suspect your original will have about 12 - 15 teeth on it. You will likely be needing 21-23. Grab a Chilton manual, if you needed, to see what you are looking for.

best of luck

enb

You should really be liking those new gears!