TCCoA Forums banner

1 - 5 of 5 Posts

·
Super Moderator
Joined
·
9,245 Posts
Discussion Starter #1
First off, this is a stock T-bird LX. Stock rim size, stock tire size (although 215s, not 205s). Ever since I've driven the car I've noticed that the speedometer has indicated a speed roughly 5 MPH faster than the actual speed of the car. Just today I took it out with my GPS to verify the inconsistency across different speeds:

Speedometer speed/GPS speed
20/15.3
30/24.5
35/29.3
45/39.3
75/70.5

As you can see, it's a pretty much constant 5 MPH difference. I know that the odometer reading is correct. I make a 237 mile trip (according to Google Maps) on average twice a month and each time my odometer reads that I've traveled 235.7 miles.

Another thing I've noticed is that the transmission shifts into final gear when the speedometer reads 40 MPH (35 MPH in reality). I have a friend with the EXACT same car (same model, engine, color, options, etc) and his shifts when his speedometer indicates 35 MPH.

Yet another thing I've seen is that on my cluster the speedometer dial is supposed to rest at the 5 MPH mark when the car isn't moving. As soon as I start rolling, the dial begins to climb up the scale.

I know for a fact that the cluster on this car is all electronic - I've already replaced two of the bulbs that illuminate it.

Any ideas as to what might be causing this? Or perhaps a remedy?
 

·
Super Moderator
Joined
·
9,245 Posts
Discussion Starter #3
Is the sprocket at the center geared or is there a way I can mark it so I know where it was originally?

By the way, this is the same T-bird my dad drives (llwta76), you've helped him (us) multiple times in the past. There's a thread he started about the Traction Assist being off constantly since we replaced the PCM...

Thanks!
 

·
Newbie
Joined
·
5,650 Posts
The needle just clips onto a post that rotates. Using a fork, you can pop the needle off and then reposition it. Get up to a speed and set the cruise and then place the needle where it needs to be for that speed. You can mark the needle where it rests so that you know where it was originally.
 

·
Super Moderator
Joined
·
9,245 Posts
Discussion Starter #5
I just took out the speedometer section and held the metal spindle underneath with a pair of needle-nosed pliers as I pushed the arm back 5 MPH. Seems like I got it! Thanks!
 
1 - 5 of 5 Posts
Top