LeSabre--The Granny Problem

My speedometer reports me as going 10mph faster than I really am, meaning that I am always 10mph slower than I think I am.

So when I go 55, I'm really cruising at the Granny Drag Strip speed of 45 mph.

My friends think I'm speeding when I'm doing the speed limit, and the other drivers think I live in fear of the limit.

(When I explain the 10mph difference my car takes flak, and I don't like people hating on my stuff)

Does anyone have a fix for this, or is it just the Curse of the 15-year old (92 model) Straight Bar Speedometer?

Are you running shorter tires (Less overall diameter) than what the car came with? Most 92 LeSabres came with 205/70/15 and would measure approximately 26.4” O.D. Are yours less than that?:sunglasse

The 15 year old tires were supposed to be replaced with identical sized tires, and they were. The specs match the car.

Goodyear (never go to this place, EVER!) put the tires on, and I'd expect them to calibrate the speedometer, but they didn't....and after Goodyear nearly got me into an accident with their negligence, I am sure as anything NOT taking my car back there again.

Is there some way to recalibrate the sensor? Or am I stuck like this?

Has the transmission or the VSS (vehicle speed sensor) been replaced since the car was new?
:popcorn:

I was thinking that either the VSS or possibly the guage in the cluster itself was faulty.

As far as my experience goes, it has not.

Considering where the car came from, I doubt it.

Taking into account the level of skill of a mechanic who can't even properly clamp a brake line, I doubt Goodyear did.

So no, I don't think it has been.

Is it easier to just swap it than to attempt to fix it? **This isn't like the infamous O2 sensor to get out though, is it? 15 years of metallic 'bonding' is not easily undone....

I don't remember if I had this problem prior to the new tires though.

If I found out that GoodYear screwed it up, I would not be suprised. At all.

It is fairly easy to get at, if I remember right. Its just a couple bolts on the passenger side of the transmission (I could be wrong tho, its been a while since I've been under my car...stupid school)

And I doubt goodyear could have screwed it up. This is just a part that dies on occasion.

Would its death only mean a 10 mph speed innacuracy?

Also, does the faulty speed reporting cause my car to shift innapropriately? (it shifts at 35, but isn't 35 really 25, making my car shift too early.....)

BTW, could you give me some more info on getting to the speed sensor?

Would its death only mean a 10 mph speed innacuracy?

Also, does the faulty speed reporting cause my car to shift innapropriately? (it shifts at 35, but isn't 35 really 25, making my car shift too early.....)

BTW, could you give me some more info on getting to the speed sensor?

Open your hood, step over to the passenger side fender with a flashlight and lean over. Look to your left and find the end of the transmission closest to you. Do you see where the axle goes in? Just above that on the body of the transmission is a wire going into a sensor. It is small and black and is about 3/4" wide. That is your vehicle speed sensor. Getting it off is not too hard, but may be very dirty. I think it is a single 10mm bolt but I can't remember for sure. Clean the whole area first, then remove it.

As to your other questions, I really do not know. The question is, how do you know you are going 10 mph slower?

^^ Couldn't have said it better myself.

The wire harness is just clipped on so its easy to pop off. Check all the wires to make sure that they aren't broken or have worn insulation.

I had a feeling that, after driving other cars, my 45 wasn't everyone else's 45.

So I had a couple people tail me in their cars, with my spedometer reading 45, and they consistantly said that according to them, I was only going 35.

My speedometer reports me as going 10mph faster than I really am, meaning that I am always 10mph slower than I think I am.

So when I go 55, I'm really cruising at the Granny Drag Strip speed of 45 mph.

My friends think I'm speeding when I'm doing the speed limit, and the other drivers think I live in fear of the limit.

(When I explain the 10mph difference my car takes flak, and I don't like people hating on my stuff)

Does anyone have a fix for this, or is it just the Curse of the 15-year old (92 model) Straight Bar Speedometer?

Did you check all 4 tires for being the proper size. Friends had a wrong size tire put on their car for a replacement. Took 6 months to find that was what was setting off their low air pressure sensor.