NEED SOME INFO ON SPEEDO GEARS FOR MY 97 GT AND T45

[ARPM]

I was looking for a set of speedo gears to use on my 97 GT cuz I have 4.10 gears and a T45. I was told that a 7 tooth drive gear along with a 23 tooth driven gear was the perfect combo for me and a *bay seller told me that I must use an Electronic Speed Calibrator cuz is the only way to get it correct. Has Any one tried the gears swap only and worked? Thanks in advance for any help you can provide.

 

[wmburns]

I always understood that for the 96-98 model year cars with a VSS sensor the rear end gears are adjusted with a PCM tune. Or with an external electronic box such as Speedcal.

The changing of the speedo gears works for the older cars.

 

[ARPM]

I always understood that for the 96-98 model year cars with a VSS sensor the rear end gears are adjusted with a PCM tune. Or with an external electronic box such as Speedcal.

The changing of the speedo gears works for the older cars.

I was told that all digital speedos needed a Speedcal and mechanical speedos like mine used gears to correct them. My 97 it's all stock and only 4.10 gears were added by the P.O.

 

[bhuff30]

The speedometer appears to be mechanical on the 96-98 mustang, but it is actually driven by an electric motor instead of a mechanical cable arrangement like the older cars. Thus, you will need a speed calibrator instead of a swapping out the gear.

 

[ARPM]

The speedometer appears to be mechanical on the 96-98 mustang, but it is actually driven by an electric motor instead of a mechanical cable arrangement like the older cars. Thus, you will need a speed calibrator instead of a swapping out the gear.

Looks like everyone agrees on the Speed Calibrator device. I wonder what will happen if a set of 7 tooth drive/23 tooth driven gear is used instead of the Speed Calibrator. Wil it change the actual reading?, Will it bring it closer to the real speed? These are things that wonder in my mind. Any how I am going to order the Speed Calibrator from the *ebay guy. he is asking for $107.00 shipping included and that's not bad at all.

 

[FoxRod87]

I put 3.73s in my 96 and swapped out the speedo gear and got it close. I think it is off by 4mph now.

 

[ARPM]

I put 3.73s in my 96 and swapped out the speedo gear and got it close. I think it is off by 4mph now.

Thanks for the info. That's what wanted to hear. Now if only one of you guys did it with 4.10 gears and a T45 I will love to see the results.

 

[pilks]

I have 4.10's in my 98gt 5speed

guys at cjponyparts did the entire install and gear speedo correction....

EXCEPT
its not perfect, in fact its off.

I believe they used a 21 tooth ill have to check my receipt.

The faster I drive the more the MPH is off.

I got a great deal from cjpony parts ($535"i believe thats what i paid cant remember" including tax for frpp 4.10s speedo correct and labor, install kit, etc.) I didnt have the money, but if i did i would have probably gotten the ford racing speedcal (i think thats what its called)

anyway the guys at cjponyparts told me that going with anything higher than a 21tooth has led to failure. i think i remember them telling me they tried a higher teeth gear 23etc. and they were breaking.(in other cars)

dont quote me on that exact cause but im pretty sure thats what i remember ill have to check my receipt again to make sure the numbers are correct.

its not the worst thing in the world. On the highway i just stay with the flow and i also have a gps that shows an est mph display. I pretty much figure its in between the 2 readings i have. its kinda ghetto but its not the end of the world. Like i said the higher the mph the greater my speedo is off.

 

[COramprat]

The 96-98 can use a gear (23 tooth) but mine tore up after about a year. That is the general problem with the plastic gear. I have a Speedcal but have since swapped my T45 for a 3650. I can let you have it for A LOT cheaper than a hundert bucks. It's used but it works. PM me...

 

[bhuff30]

I've often read that the 23 tooth gear is pretty much at the limit of reliability. It just has too many teeth and not enough strength to be reliable long term. I run a 23 tooth in my 2.3/C4 and tore up one as well. Other gears are more reliable, but the 23 tooth is just at the limit.

 

[ARPM]

The 96-98 can use a gear (23 tooth) but mine tore up after about a year. That is the general problem with the plastic gear. I have a Speedcal but have since swapped my T45 for a 3650. I can let you have it for A LOT cheaper than a hundert bucks. It's used but it works. PM me...

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