Cell Phone Speedometer

[Adam Roby]

How accurate are those speedometer apps?
In my wife's car it seems bang on, but in my Jeep while I am reading 110 km on my speedometer, her app is showing only 101 km.

Everything is stock in my Jeep, no lift, normal tires, etc...
What can make my speedometer be so far off if indeed it is?

 

[Hdale85]

Pretty darn accurate actually. I've been using one on android for a while now as I can't get the speed sensor out of the diff...... need to try and tackle that again.

If your tires are in fact stock size, then it could be the pigtail connector starting to go bad or the speed sensor starting to go bad. Mine up until I broke it more was still reading speed it was just WAY lower than I was actually going.

 

[TwoBobsKJ]

I've found the GPS apps to be very accurate and use it when I know I'll be driving through an area with a lot of radar-happy troopers

As far as the speedo goes on the Liberty... Many find them to be off, some by quite a bit. Even with factory tires mine was off. With larger tires with 4.10's I expected the speedometer to be off even more but it didn't really change. It reads slow by 5% - so if it's reading 70mph I'm actually traveling about 74mph. I've taken the Libby to a couple of different dealers to see if they will do a "pinion reset" to correct the speed reading.

The service writer looks at me like I'm asking to date his daughter or something...

Bob

 

[renegade 04]

I corrected the problem by just taking apart the instrument cluster and just moving the hand forward.

 

[teeje]

Change the sensor and your diff fluid. Corrected mine


Sent from my iPhone using Tapatalk

 

[Adam Roby]

Change the sensor and your diff fluid. Corrected mine

Diff fluid... hmmm.. what's the logic there? I was planning on changing it, since I have no clue when or if it has ever been done. How expensive/difficult is it to change the sensor?

 

[teeje]

Diff fluid... hmmm.. what's the logic there? I was planning on changing it, since I have no clue when or if it has ever been done. How expensive/difficult is it to change the sensor?

Relatively easy. There's a (8mm i believe) on the sensor, take that bolt out and turn the sensor back and forth so it breaks loose and it'll pop right out. As far as the diff fluid goes, there's a fill plug, take the fill plug out and get a hose and suck on it until the fluid starts to come out (get a nice drink to get the taste out too) and spin the wheels (with the jeep on jack stands of course) until most of the fluid comes out. This is how I did it and it worked great. The problem is, the fluid gets dirty over time and the sensor is magnetic. Once the fluid gets so dirty, it contaminates the sensor and it becomes harder for the sensor to read the teeth. Should work well for ya. I used Mobile 1 Synthetic with the friction modifier that it calls four. Buy 2, you'll need it.