Need Second Opinion

[Street Fighter]

i am new to the SHO game(a week into it). the car i bought has most of the common 95 ATX problems. and here is ANOTHER one i found the hard way. it appears my speedometer is off, alot actually, b/c i had the cruise set at 65 mph and got pulled over for 75 mph. so not only do i have to fix an assload of stuff now i have pay for a ticket!
anyway, i assume the VSS is causing this? is it unheard of for the VSS to cause a 10 mph difference? i think it becomes farther off the faster i go. it is also causing problems with my shift points. sometimes it's unsure what gear to select.
i just wanted to see if this sounds in line with a faulty VSS? thx.

 

[SHOtimer]

Your VSS may well be bad, if you are having shift problems but that would in no way affect your speedometer. That is a cable driven device which attaches directly to the transmission, it is purely mechanical. Their might be a problem with the cable, or your tires might be an incorrect size causing the problem.

Doug

 

[Street Fighter]

the tires are the right size, i checked already. so you're saying the VSS doesn't have anything to do with the speedometer? the speedo cable doesn't run through the VSS? i ask b/c on a mustang the speedo cable is connected through the speed sensor.

 

[roswell998]

the tires are the right size, i checked already. so you're saying the VSS doesn't have anything to do with the speedometer? the speedo cable doesn't run through the VSS? i ask b/c on a mustang the speedo cable is connected through the speed sensor.

Yes it is connected through the VSS, BUT it is a mechanical straight through so a bad VSS outputs an electrical signal which is out of spec, but that does not affect the rotational speed of the pass through shaft and the connected cable.

You might have a bad speedo head. Maybe someone knows of speedo calibration procedures. Perhaps a search of the forum will turn up something on that subject.

 

[Street Fighter]

does anyone know the stock tooth count on the speedometer gear? i'd rather check for something like that before i start buying a bunch of crap.

 

[Cobraii976]

well be prepared to remove the rear motor mount and anything else in the way to get to the speedo gear. It's located on the VSS. If I were you I would take it to a local speedmeter shop have it tested then calibrated and then fight the ticket.

 

[rangerj]

Call, or better yet visit, a Ford dealership parts department. Check on whether or not there are more than one speedo gears with a different number of teeth. The gear should be different for 14 inch wheels, versus 15 inch, or 16 inch wheels.

I don't know about Ford and the SHO, but I ran into the same problem on a Chrysler product a few years ago. Chrysler has three different speedo gears, 19 teeth, 20 teeth, and 21 teeth that apply to the different sized wheel and tire combinations. A one tooth difference would be off by 3 mph at 35 mph, but the speedometer error could be more depending on the trans gear ratios, so that 10 mph was very possible.

You may also get the same information at a shop that specializes in speedometer calibration. If you find that your speedometer is that far out of calibration you should document it and get a sworn statement from a calibration shop, and a receipt for the repair (recalibration). This service is usually about $100 to $150. How much is the ticket and the increased cost of insurance?

Then fight the ticket as you did not have the required "intent" to violate the speed laws. Best of luck, rangerj

 

[Street Fighter]

Call, or better yet visit, a Ford dealership parts department. Check on whether or not there are more than one speedo gears with a different number of teeth. The gear should be different for 14 inch wheels, versus 15 inch, or 16 inch wheels.

I don't know about Ford and the SHO, but I ran into the same problem on a Chrysler product a few years ago. Chrysler has three different speedo gears, 19 teeth, 20 teeth, and 21 teeth that apply to the different sized wheel and tire combinations. A one tooth difference would be off by 3 mph at 35 mph, but the speedometer error could be more depending on the trans gear ratios, so that 10 mph was very possible.

You may also get the same information at a shop that specializes in speedometer calibration. If you find that your speedometer is that far out of calibration you should document it and get a sworn statement from a calibration shop, and a receipt for the repair (recalibration). This service is usually about $100 to $150. How much is the ticket and the increased cost of insurance?

Then fight the ticket as you did not have the required "intent" to violate the speed laws. Best of luck, rangerj

i'm not worried about the ticket. i'll just have my lawyer take care of it. i get alot of tickets...shh.
man this thing(SHO) is killing me. i would like to service the eng., trans., and cooling but every damn day i find another "sensor" that needs replaced. i haven't even got the chance to detail it yet b/c i'm checking out some sort of problem each night. this thing is falling apart faster than i can get s#$% replaced or checked.
i guess i'll add a speedometer head and VSS to the "checkout" list. although i'm putting towards the bottom. i already have a O2 and PFE sensor coming in the morning.

 

[1995mtxsho]

Perhaps you might find some similarity in this thread?
http://www.shoforum.com/showthread.php?p=367919#post367919

 

[Street Fighter]

i don't have the bouncing problem. mine seems to work fine until i hit about 55-60. then the needle slows down even though i am accelerating. i do believe it is correct until i reach these speeds. after that...i have no idea how fast i am going.