1999 GT

i installed a mach 1 gauge cluster on my GT and everything works perfect, except the speedo is off by 5mph...i thought maybe because machs have 3.55's but what do you guys think-

cliffyk

It may be because Mach I's came with 3.55 gears, however I was not aware of any differences in the cluster's servo motors. Did you swap the electronics from your old cluster, if not how did you deal with PATS?

Also, if it's 5 mph off at all speeds then it's a needle placement issue, not gearing related...

Tazzy

Mine was the same on my 04 GT , I used my old electronics and used my GPS and the diablo to set the gears. Now the speedo is correct.

1999 GT

yea i swapped the circuit board off the stock cluster, everything else is accurate because i checked them off the digital diagnostic readings but i'll just move the needle...i was just curious to see if this happened to anyone else

Tazzy

If your stock cluster mph range was lower ie 140mph and the mach cluster is higher ie 160mph moving the needle will not be as accurate as changing the gear ratio in the ecm with a tuner.

1999 GT

both clusters go to 150mph

Jordan123

Where did you find the cluster at? I have been looking everywhere and i can t fnd any

1999 GT

prestigemustang.com it came out of a wrecked 03 mach...and yea, they're are very hard to find so i jumped on this one when i saw it