People stare at me at the beach. I wouldn't mind that so much if they didn't keep trying push me back in the ocean. Actually, I'm about 40+ years past wearing a speedo at the beach.

On the other hand, I finally found my hand held GPS unit from my last racing days and used it to check the speedo on my '96 Ram 1500. I thought it was off as I would run over the limit and most vehicles would pass me. My speedometer is reading high. I talked to the previous owner and when he bought it, the owner before him said it ran high. It's is now on it's third transmission. The one in it is new and was a rebuild of the one built before. That was a Jasper unit.

How does the speed sensor work on these? Does it read the speed itself or does the computer read the sensor signals and convert it to a speed reading? Where is the VSS on these? I'd like the speedometer to read right. Both to avoid tickets and also not line miles faster than I actually am.

 

What year is the truck? Where the Speedo gets its info from changed over the years.

 

1996 Ram 1500 SLT Laramie 4X4. It has 3.5 rear but acts like it has 3.73. As far as I know, the rear hasn't been changed. It runs, drives and shifts just fine. Just a high reading on the speedometer.

 

You maybe able to change the pinion factor thru the ABS module, That is you have a output sensor on the tail housing of the transmission. Or if you have a speed sensor you can change the gear by the color of the gear.

 

Speed sensor is on the t case, You many want to pull it out and see what gear is on it. Different gears for different axle gears.

 

Yeah, verify what gears you have in the diff. Various places sell the driven gears for the VSS. It's easy to correct.

 

I've changed the driven gear to compensate for over size tires. I haven't done one on one of these trucks and wanted to make sure the system was similar. I had a GMC van a while back that had shifting issues and the speedometer was WAY off. That one turned out to be a combination of a stuck solenoid in the transmission and a pin setting in the computer. Talk about fun tracking it down.

This is a good solid truck but I don't want to be throwing parts at it. My initial suspicion was when the transmission was rebuilt the first time, the wrong drive gear was put in. I'll be near the stealer later today and see what they say. Probably the suggestions here and my suspicions.

 

I have an old Haynes manual for my truck. I like these for the specifications they have. I'm quite capable of most repairs without a book. However, while looking to see what it said about the VSS on the transfer case tail shaft, I noticed it mentioned two setting for the sensor. I'm wondering if the first time the transmission was rebuilt, if that got put in wrong. The second time it was rebuilt, they put it back like it was before. This could explain how the previous two owners had the speedometer reading high. This truck could very well have 5000-10,000 less miles than the clock is showing.

 

Then the odometer is reading higher when driving, thinking you are doing the speed limit?

 

Yes. Most traffic passes me. On the interstate, an indicated 80 mph was 73.2 on my hand held GPS. The only way to really know what gears are in the rear is to pull the cover and I'd like to avoid that. I tried put it in gear to count drive shaft rotations but forgot it has a Surgrip rear end. I'll swing by a transmission shop I've done business with since the early 80's and see what they say.