speedometer

[snake2144]

need some help here, my speedometer is off by eight miles per hour would anyone know why?

j

 

[viprtek]

need some help here, my speedometer is off by eight miles per hour would anyone know why?

j

What size tire does your truck have on it?

 

[snake2144]

305/40/22 i believe that they are stock

 

[SilvrSRT10]

need some help here, my speedometer is off by eight miles per hour would anyone know why?

j

How did you determine that and is it high or low?

 

[snake2144]

radar video screen that shows your speed ran past it several times and it was off by 8 miles per hour. if i show 60 on the gauge i am running 52

j

 

[hemi killer]

I would not trust that. Get someone to go out with you in another car that has factory size rims and tires (new car) and go side by side on the interstate. That should tell you how much you are off.

 

[ViperJeff]

Just a little insight....

The Sheriffs Department here calibrates there speed checks 3 mph high, just to make people think their speeding

So it may not be all what you think

Find a better place to verify your speed

 

[viprtek]

GPS is the only true way to measure your own speed.

 

[viprtek]

GPS is the only true way to measure your own speed.

 

[snake2144]

hemi keller thanks but i already did that and i was of by 6 to 8 miles per hour.

 

[SilvrSRT10]

I wonder if someone put 4.56 gears in it before he got it. I'm not sure which way or by how much that would throw his speed off. Any thoughts? I think it would make him read faster than he was actually going.

 

[westmintrans]

Is it a QC or RC because the speed sensor in the auto's for the QC is common for going out. they get debris from inside on the ends and cause all sorts of problems. If his rearend was changed it would have to be a lower gear by about 10% like from 4.10 to 4.56s or from 4.56 to 4.88.

 

[tinygiants]

Do a stopwatch run over a marked course. Around here we have 5 mile stretches that are laid out for truckers. Set the cruise control and time the run. That would get you a nice accurate speed in lieu of the GPS.

Dale

 

[TheMoparConnection]

Follow a mile marker and check your tripodometer. That will tell you if you're off. If thats off take in to your local dealer and have them check the pinion factor. It's possible it has never been set.

 

[Bone]

There is a way to recalibrate the speedometer/gauges, or at least someone posted on this awhile ago. I believe it had something to do with holding in the trip button while cycling the key on and off, but not starting the engine.

 

[TheMoparConnection]

yeah. you can try to recalibrate it. with key off hold the trip button down and turn the ignition on. keep holding for a couple of secs until all the cluster light come on.

 

[snake2144]

thanks guys i will try this in the morning see if it works, if so i will let you know for future owners who may have the same problem

 

[Prof]

I seem to recall that someone posted saying that tire size has nothing to do with the speedometer...that there is a sensor on the drive shaft or something that calibrates rotations...does anyone else recall that post?

 

[WILDMAN]

WILDMAN

I had the 4:56 gears put in my truck and don't have any problems with the speedo. Tire size or gear change should not effect the speedometer, so I am told.

Wade

 

[rottenronnie]

My '03 Hemi truck came factory with 17" wheels. I had them changed to 20" before I picked it up. The speedo was off because of this but the dealer fixed it in 2 seconds with a laptop.

Ron