Speedo off after Gear install

[97woodward]

Hey guys, yeah as ive told you my 4.10s were installed two days ago and I now have the car back. I noticed right away that my speedometer was off the second I got on the highway. Probably around 9-10mph off. I would have called my mechanic back but he had already closed for weekend and he doesnt reopen until Monday.


I asked him if he installed the Speedo Calibrator and he said he did. He specializes in Mustangs and is very well known, he also does gear installs all the time. Is there a way for me to figure out if he actually put it in? And if he did is there a reason why it could still be off? Any help is appreciated

 

[Willis_98GT]

in your case. it was either a dallas mustang speedcal. or he changed the out the actual speedometer gear. check around.

 

[96sohc]

The little gears themselves aren't dead on accurate, especially over 3.73's; thats just the nature of it.
If you want dead-on precision, you need a Speedcal.

 

[97woodward]

IS there a way to check and see if i got one?

 

[96 blue moon]

I would talk to your mechanic and see if he changed out the old speedometer gear and installed the correct one for 4.10 gears.

 

[nyuk98gt]

Guys:

For the record, there is no gear alone that will fix the speedo. The best option is to leave the stock gear in (orange, 19 teeth IIRC) and use a SpeedCal or Abbott ERA calibrator. FWIW, I have had a SpeedCal installed for many years and my speedo/odo is dead-on accurate. It is a good little device and well worth the $100. Installation is pretty easy and the instructions are great with lots of pictures for reference.

+1 for asking your mech/tech what he installed. If he used the "white gear" (21 or 23 teeth - sorry, can't remember the exact number) then it will be in the ballpark but it will still read more speed/miles than actual (so, more than 1 mile for every real mile travelled). The teeth are very thin and they will fail in time. The bottom line is, why register more miles on your car than you are actually putting on the car?

HTH,

Chris

 

[glittle75]

just for my .02

I got 4.10's in my 98 gt, and ordered the steeda abbot, (Black) for automatic, and had the g/f drive her cavalier in front of me, and every speed was dead on.

steeda makes good stuff.

 

[Jrgunn5150]

Twist the shifter knob off, then pop the shifter bezel up and out. In the cavity on top of the tunnel should be your speedcal sitting there.