speedo cable

['97 V8]

i searched asnd called autozones and lordco's..equiv to autozone in canadia, and got no true answer. bien that ill be runnin 33" tires with 4.10's, where can i get a speedo gear that accomadates the change? ive read posts on how to take it out....preety easy bit no one has said where to get a different sized one. please prove me wrong and let there be a thread ot there...or did autozone screw up and have one...adding more to the debate of why we dont need autozone.

 

[section525]

I got mine at the Ford dealer. Do you know what color you are going with?

 

['97 V8]

they come in colors?

 

[section525]

Yeah, the color = tooth.

But I'm thinking that running 33s with 4.10s will probably put you pretty close to stock. So the speedo could be really close to acurate. I think "Robert" has a pretty good thread with calculations and whatnot on this site... somewhere.

 

['97 V8]

yeah i read it and did a calculation..or was it the gear ratio to stock rpm with tires. what color are your runnin....just out of curiousity

 

[section525]

I think I am running... shoot I don't even know. Maybe green? I could look but it would be useless for yours if you're going with 4.10s.

This is what I figured for yours. Now, the math owns me so you may want to double-check. As you can see they're pretty damn close in the long run.

 

['97 V8]

yeah...oh well it'll be a good excuse to get out of a ticket if i ever manage to get one. thanks section....your my hero

 

[410Fortune]

Um isnt 97 the year they switched to the non cable operated speedometer?

Your Ford dealer has the gears.
If you dont have a cable operated speedo then you have to calibrate the speedometer at the computer.

 

[section525]

Um isnt 97 the year they switched to the non cable operated speedometer?

Your Ford dealer has the gears.
If you dont have a cable operated speedo then you have to calibrate the speedometer at the computer.

Where have you been the last few days? We've been worried sick!

I think 94 was the last year of the cable. Then 97 was the last year of the tcase vss. Now everything is built into the RABS.

 

['97 V8]

but but....from what i read on the furom 97 was the last year they used the vss, and in 98 they switched to computer stuff. thats whta i read from the sticky. mine is an early 97...built in 96 mountaineer.

 

[section525]

Well what happened was they switched from a VSS sensor (who's sole purpose was to give the truck's speed) to utilizing the RABS (rear antilock brake sensor) to get the axle shaft turns. This way you can swap gears out and it will not effect your speedometer. But yes, since they switched sensors, you must now get the computer reprogrammed to change your speedo. But luckily you're an old skoo 97 with the good stuff still.

 

['97 V8]

should i take it into a stealership and have it done?

 

[410Fortune]

NO
You go to the dealership to buy the correct gear, based on the # of teeth you need, once you figure out the ratio.
First remove your speed sensor, note the color of the plastic gear and count the number of teeth.

I have been partying and also working on trucks the last couple days, don't worry you cannot get rid of me that easy!

 

['97 V8]

okie...and dont mind me for bien stupid, but umm how do i know how many teeth that need to be added.

 

[section525]

I don't think you need to change your tooth count at all.

 

[Glacier991]

<== Still has all his teeth.

 

[410Fortune]

Section is saying with 4.10 and 33's you put yourself right back to stock.
Have you tested your MPH?

First count the nuber of teeth you have on your stock gear and get the color.
Then determine which way your speedo is off, if any at all.
Then go buy the gear with one fewer or one more tooth then stock.
Swap gears and check the speedo again, it is very likely that the gear you have is the correct one as Section said. But not all 33" tires are the same size
The changes you can make by going with a different speedo drive gear are not as precise as you may think, changing one tooth can have quite an impact on the speedometer.

On my truck with the 5.0L, 4.10's, and 35" tires I cannot get my 88 speedometer to be acurate at all speeds. the 21 tooth gear I have installed is the most # of teeth they make (I believe, I think I may have seen aftermarket gears now with more teeth) and with my combo my speedo is still off. When I put my 33" tires on it is ALOT more accurate (especially at lower speeds) but it is still no GPS.

I am not too worried about this because I plan to ditch my stock speedo and tach shortly......

 

['97 V8]

i'll take you and sections word for it. if its like a miniscual change like a couple off its ok. reason bieng is that the little efer cops here in vancouver pull you over just goin 10kph over. last thng i need is a smart a$$ cop givin me hell...btw there tickets are 135 bucks for speedin..and get this, you get a discount of 25 dollars if you pay within 10 or 30 days. cant remeber which. but hell i'll tell him my speedo is off a bit.

thanks john and 410 for your help. i'll check it out saturday.

 

[410Fortune]

it will be off by a percentage, that perentage will increase as you get to higher speeds.

So say it is reading 12kph when you are doing 10, when you get up to a higher speed the speedo may read 50 kph when you are doing 59kph.

I was very surprised to see how far mine is actually off when I got a GPS unit in my truck.
Also the radar trailers they put on the side of the road and display your speed are not exactly 100% accurate, though they were more acurate then my speedometer!
My GPS is acurate to within 3 ft.

Our ticket system here in Colorado is similar, you get $$$ off and less points if you pay it early and avoid a court date.

 

[ma96782]

Next time you see a cop on the side of the road w/ a radar gun.........ask him to help you out.....in the interest of science or public relations.....explain to him your problem.......he'll more than likely agree.....after all, you want to get your speedometer FIXED so you DON'T speed. The cop will also enjoy his day too.....helping you out in the name of science and public relations.

Travel through his trap zone at the recommended speed (steady now).......he'll tell you what you ACTUALLY clocked at (MPH)......then take that information down to the dealership. Speedometer says _____ MPH, cop's radar said it was actually _____ MPH.

OR

Go to a shop that calibrates speedometers (ask the cop where his vehicle is calibrated at).

Aloha, Mark

PS.....Please make the arrangements with him BEFORE you go SPEEDING through his radar trap.

Here is another guy trying to figure out the correct gear for his speedometer problem.

http://www.explorerforum.com/forums/showthread.php?t=154152