speedo does not read correct mph

[illumastorm]

i just bought a 94 ranger, 4 banger, 5-speed manual, stock size tires. driving it home i noticed the speedo seemed off, i called my wife on the cell and while she was following me she said she was doing 55 mph and at the same time the ranger speedo showed 47 mph. i do know the tranny was replaced and i was wondering what might be wrong and how can it be fixed? if it was a little off i could deal with that but being almost 10 mph off i think i need to fix that otherwise the cops will be stoping me a lot.
thanks

 

[locovaca]

There's a good writeup in the tech library:

http://www.therangerstation.com/tech_library/Speedogear.html

 

[dennis461]

oh oh

i just bought a 94 ranger, 4 banger, 5-speed manual, stock size tires. driving it home i noticed the speedo seemed off, i called my wife on the cell and while she was following me she said she was doing 55 mph and at the same time the ranger speedo showed 47 mph. i do know the tranny was replaced and i was wondering what might be wrong and how can it be fixed? if it was a little off i could deal with that but being almost 10 mph off i think i need to fix that otherwise the cops will be stoping me a lot.
thanks

Does it stop at 47, or will it go higher?

Meaning, if your driving at 45 does it read correctly?

 

[Joe_Roofer]

Errr, the cops would be stopping you for driving to slow?
My exploder has the same problem, sounds like an easy fix...
I've got to much other stuff to wory about right now.

 

[Wicked_Sludge]

read it again. he was actually doing 55, when his speedo read 47. meaning if he was doing 55 by his speedo, he'd be doing over 65 actual speed.

 

[pocket-rocket]

Changing the gear on the speedo cable is cake. I just did mine after going from a 3.45 rear gear to 3.73, but I had to drive my truck to the dealer that had the gear in stock and mine was the opposite of yours, lol. I was driving down US20 and keeping up with traffic (65mph speed limit and most people do 70-75) and my speedo read 80-85 most of the time One bolt keeps the hold down in the side of the trans, get it out and the cable comes out with the gear on the end. Pull the clip off the gear and the old one slides off. Put the new one one, put the clip back in, push it back in the trans, put the bolt back in and tighten it down and your done. The hardest part is finding a dealer with the one you need in stock. Places like Advance and Autozone don't stock them. I gave them $4 and got change back for mine too

 

[illumastorm]

thanks guys, sounds like it will be an easy fix, just need to figure out the right gear tooth i need and replace it.

 

[illumastorm]

one more thing, since i know the tranny was replaced i am sure the guy got it from a ranger with a different axle ratio then what this has, so that is why the speedo is off?

 

[Wicked_Sludge]

the doner ranger could have had different axle gear ratios or different tire sizes....or both.

 

[illumastorm]

ok i went to that web site for figuring out the gears but i am confused!!!
i remove the cable and it has a black gear on it now, i did the math thing and it shows i need a red gear, i think, or either the pink?
it has 225-60r15 tires, axle ratio is 3.45 . if someone else is better at figuring this out let me know because i suck at math even with a calculater

 

[locovaca]

Well, you showed 47 while doing 55.

55 - 47 / 55 = .145 (14.5% too slow)

20 * (1 - .145) = 17.1

So you're looking for a white gear.

 

[illumastorm]

i knew i was wrong,
will be getting a white one this weekend. thank you sir