FINALLY...anyone with Speedo Problems look at this
 

So as some of you may know i have been having a hell of a time trying to fix my speedo. Well today I finally got it right on the mark. So here is how I fixed it.

The background:
The speedo has been off since I bought the car in February. It has 3.73 gears and 275/40 tires. I knew that the guy tried to fix it by using the 23 tooth gear speedobut it was still off.

The FIX:
1. WellI first found out that the 23 tooth speedo gears are crap when I inspected it and the gears were half torn off (this was also confirmed by a local shop that specializes in speedo correction). So I took that out and replaced it with a more reliable 21 tooth gear. For me this is thesame as thestock one for my car which came with 3.27 gears. If you aren't sure check out this page to help you or PM me.

2.Then I purchased the SpeedCal from Dallas Mustang (This is almost a must for 96-98 mustangs with electric speedo). Installed it and used their calculator to find the code for the SpeedCal. It is very important that you know which speedo gear and rear gearsthe car had stock as well as the current setup (this was one of my big problems). I thought the car had a 19 tooth speedo gear stock.

3. If the gauge overlays have been changed you should suspect that the needles might be in the wrong places. This is how to fix the needles:
(a). You will need an external tech to measure the engine RPM. I had one of these from craftsman. I taped into the tan/white wire behind the gauges. I then compared the reading on the meter to the car's rpm gauge. If they are off, physically remove the needle on the car's rpm gauge and place it in the right place (it is important that the car's RPM gauge is correct cause you will use it to verify the cars speed).
(b). Then use this site to find out certain speeds at certain RPMs and make a list.Then go for a drive. Set the car at a specific RPM and use the information you gathered to check to see ifthe speedometer has the right speed for the RPM that you are traveling at.If they are notequal, physically remove the speedo needle and place it at the right speed (USE CAUTION IF YOU DO THIS WHILE DRIVING). Check to see that it is the speeds match up to a verity of RPMs.

After those three setups you should have an accurate speedo.

RE: FINALLY...anyone with Speedo Problems look at this
 

So, do you have a speedcal for 94-98's with a 5spd tranny? Do you want to sell it since you already used it? I had 3:27's stock as well and am changing to 3:73's!

RE: FINALLY...anyone with Speedo Problems look at this
 

I am using the SpeedCal. You should definately get one!

RE: FINALLY...anyone with Speedo Problems look at this
 

Mechanical

RE: FINALLY...anyone with Speedo Problems look at this
 

mine is a late 98 and it has an electric speedo. it doesn't run to the PCM like the 99+ do that is why I can't use a tuner to adjust it.

RE: FINALLY...anyone with Speedo Problems look at this
 

Mine is a late 98 model also, but it's a mechanical speedo. I had to get a Speedcal as my SCT did not work.

RE: FINALLY...anyone with Speedo Problems look at this
 

doesn't mechanical mean cable driven? cause if it is cable driven, a speedcal wont help you. This is how it is for my car:
1. Theiris a unit called a VSS (vehiclespeed sensor)connected to thetransmission (this iswhere thespeedo gear is attached).
2. The VSS is a small generator that sends out an "ELECTRICAL" AC signal to the speedo (in pre-99 models), or to the PCM (99+ models).

The SpeedCal contects "in-line" to that signal wire and modifiesthe signalbased on the code that you select for the speedcal. This is the only way to modify the signal on pre-99 models. 99+ models can flash the PCM using a tuner to modify the signal.

RE: FINALLY...anyone with Speedo Problems look at this
 

Its electrical: theres no cable

RE: FINALLY...anyone with Speedo Problems look at this
 

I basically was talking about the mechanical odometer as opposed to the electical/digital odometer

RE: FINALLY...anyone with Speedo Problems look at this
 

So in other words you have to have it hooked up at all times for you to maintain the correct speed? I was thinking it flashed the computer I guess! Dammit now I have a $15 plastic gear and could own a speedcal for $85........?????? Maybe I'll get one anyways