how to calibrate a speedometer? - Ranger-Forums - The Ultimate Ford Ranger Resource


General Technical & Electrical General technical and electrical discussion for the Ford Ranger that does not fit in any other sub-forum.

Reply
 
LinkBack Thread Tools Search this Thread
  #1  
Old 03-21-2011
Member
Thread Starter
 
Join Date: Oct 2010
Location: aspers, PA
Posts: 801
how to calibrate a speedometer?

so i put bigger tires on my ranger, i have like 29 inch tires from like 24 - 25 inch tires and well obviously my speedo is really off, so i want to know if any of you know how to calibrate a speedometer, i did find one how to but it wouldn't let me open it. so any help will be greatly appreciated, thanks?
Reply With Quote
  #2  
Old 03-21-2011
Member
Thread Starter
 
Join Date: Oct 2010
Location: aspers, PA
Posts: 801
well i talked to a mechanic today, and he told me that the speedo reads like a ring gear in the tranny, any of you know which gear that is, or if its different for my year, and what kinda gear do i need, and what vehicle i can get it from? thanks!
Reply With Quote
  #3  
Old 03-21-2011
TheRedRanger01's Avatar
Member
 
Join Date: Jul 2010
Location: San Antonio, TX
Posts: 200
Just do the math. Its wasted money when you could just figure out what your real speed vs your displayed speed is. lol
Reply With Quote
  #4  
Old 03-21-2011
Member
Thread Starter
 
Join Date: Oct 2010
Location: aspers, PA
Posts: 801
eh, but its really ****ed up, its not always five slow, my friend behind me was going 65 when it said 55 so its just a pain in the ***. i just want to know if there is another vehicle i can get the ring gear out of which will be fairly cost effective to go to a junk yard and get it
Reply With Quote
  #5  
Old 03-21-2011
dieselT4x4's Avatar
Member
 
Join Date: Dec 2010
Location: Pembine, WI
Posts: 65
no... it's maybe a 2mph difference. there are calculators online to figure it out
and yes the sensor is a speed sensor in your differential. don't take it out, I had a broken one in mine for a while and it really screwed up my tranny.
Reply With Quote
  #6  
Old 03-21-2011
NJmaz's Avatar
Member
 
Join Date: Jan 2011
Location: Eatontown, NJ
Posts: 76
My friends speed sensor was messed up in his 99 2wd auto trans. As soon as you went over 60, the speedo would flip out, and the truck would downshift into second after a few seconds. So yea, dont screw with that
You may be able to take off the needle and adjust it a bit, but that wont get you exact really.
Reply With Quote
  #7  
Old 03-22-2011
Billy4x4's Avatar
Member
 
Join Date: Mar 2008
Location: Kawartha Lakes
Posts: 626
tuner/programmer
Reply With Quote
  #8  
Old 03-22-2011
Member
Thread Starter
 
Join Date: Oct 2010
Location: aspers, PA
Posts: 801
well its def way more that 2 mph, believe me i'm the one driving it, it wouldn't even go past 65 and i could tell i was flying when i was coming down the hill, and there's a spot a little after 50 were when i slow down it hesitates before going down, now mines a manual transmission a lot simpler than an auto, if the ring gear is up front then it should be fine to replace it, however if i have to take half the transmission apart then i'm obviously not going to bother, it would be nice to have an accurate speedo so when i see a cop on the highway it would be nice to know how fast i need to slow down to in a hurry,
Reply With Quote
  #9  
Old 03-22-2011
Member
Thread Starter
 
Join Date: Oct 2010
Location: aspers, PA
Posts: 801
is there a programmer for an 89? that's still probably more expensive than knowing what vehicle i can take the ring gear from and getting from a junk yard and having the experience of taking it out.
Reply With Quote
  #10  
Old 03-22-2011
Toms994x4's Avatar
Member
iTrader: (4)
 
Join Date: Jul 2009
Location: Sanford, NC
Posts: 1,300
Got a GPS?
Reply With Quote
  #11  
Old 03-22-2011
Member
Thread Starter
 
Join Date: Oct 2010
Location: aspers, PA
Posts: 801
nope, too poor, i use map quest? that's the issue i would borrow one form somebody but if it gets stolen it a big chunk of change outta my pocket, come on guys i like getting my hands dirty anybody know what gear i need?
Reply With Quote
  #12  
Old 03-22-2011
BlackRanger04's Avatar
Member
iTrader: (2)
 
Join Date: Jun 2010
Location: Louisville,KY
Posts: 1,240
Quote:
Originally Posted by Toms994x4 View Post
Got a GPS?
A GPS would actually be the cheapest way to go ... I bet you could find one on e-Bay or Craigslist for 50 bucks.
Reply With Quote
  #13  
Old 03-22-2011
V8 Level II's Avatar
RF Veteran
iTrader: (4)
 
Join Date: Nov 2004
Location: Michigan
Posts: 7,831
All of this talk about ring gears, programmers and rear axle sensors is BS.

The 89 speedometer is cable driven off the transmission (2WD) or the transfer case (4WD). There is a small gear that can be exchanged to another tooth count to correct the speedometer for axle ratio and/or tire diameter changes. The gear is located on the VSS sensor that drives the speedo cable so the VSS must be removed to access the gear. Swapping to the gear with the correct tooth count will fix the speedometer error IF your combination is still within the range allowed by the available gears.

Go to the Tech Library at www.therangerstation.com and read the section on 94-back speedometer correction for more info.
Reply With Quote
  #14  
Old 03-22-2011
01RangerEdge's Avatar
Scrambles the DeathDealer
iTrader: (11)
 
Join Date: Jul 2009
Location: Jackson, MO
Posts: 7,598
^That's how speed is read on both my 77's.
Reply With Quote
  #15  
Old 03-22-2011
Toreador4x4's Avatar
Member
iTrader: (6)
 
Join Date: Apr 2007
Location: Livonia, MI
Posts: 3,958
Quote:
Originally Posted by rwenzing View Post
All of this talk about ring gears, programmers and rear axle sensors is BS.

The 89 speedometer is cable driven off the transmission (2WD) or the transfer case (4WD). There is a small gear that can be exchanged to another tooth count to correct the speedometer for axle ratio and/or tire diameter changes. The gear is located on the VSS sensor that drives the speedo cable so the VSS must be removed to access the gear. Swapping to the gear with the correct tooth count will fix the speedometer error IF your combination is still within the range allowed by the available gears.

Go to the Tech Library at www.therangerstation.com and read the section on 94-back speedometer correction for more info.
and it took 13 replies for someone to be correct...my face was turning red as i read down the list of the tuners and OSS tone rings in the transmission...remember guys, there was a time when you could do things to vehicles without pressing buttons
Reply With Quote
  #16  
Old 03-22-2011
Member
 
Join Date: Mar 2010
Location: Redding, Ca
Posts: 76
A speedometer shop can make you a ratio adaptor. Any ratio you need. It just mounts to the transmission and the cable mounts to that. Then if you go back to orginal tire size just pull it off. Some other size? just change gears in the adaptor. It's a little box about 1 X 2 x 3/4.
Reply With Quote
  #17  
Old 03-22-2011
StxDangerRanger's Avatar
RF Veteran
iTrader: (2)
 
Join Date: Dec 2010
Location: Flat Rock, Mi
Posts: 6,313
Quote:
Originally Posted by rwenzing View Post
All of this talk about ring gears, programmers and rear axle sensors is BS.

The 89 speedometer is cable driven off the transmission (2WD) or the transfer case (4WD). There is a small gear that can be exchanged to another tooth count to correct the speedometer for axle ratio and/or tire diameter changes. The gear is located on the VSS sensor that drives the speedo cable so the VSS must be removed to access the gear. Swapping to the gear with the correct tooth count will fix the speedometer error IF your combination is still within the range allowed by the available gears.

Go to the Tech Library at www.therangerstation.com and read the section on 94-back speedometer correction for more info.

Finally somebody gets the right answer. and that "IF" in his statement is actually a no. trust me, i've got 32's and they used to be 29's (i think). there isn't a better gear you can install. just calculate the difference.

Quote:
Originally Posted by Toreador4x4 View Post
and it took 13 replies for someone to be correct...my face was turning red as i read down the list of the tuners and OSS tone rings in the transmission...remember guys, there was a time when you could do things to vehicles without pressing buttons
You were getting red? i was going nuts! he has an 1989 ranger. some members on this forum weren't even born then! in 1989 there was no OBII all your diagnostic tools nowdays would be worthless on that truck.
Reply With Quote
  #18  
Old 03-22-2011
Member
Thread Starter
 
Join Date: Oct 2010
Location: aspers, PA
Posts: 801
yeah i actually found out about that little pinion looking gear today, while researching, now i just need to find the tooth count needed and i will be on my way, and i for the last time i would just calculate the difference, but its really ****ed up. anyways, thanks bob, too bad, i found that out before i had a chance to read your post.
Reply With Quote
  #19  
Old 03-22-2011
dieselT4x4's Avatar
Member
 
Join Date: Dec 2010
Location: Pembine, WI
Posts: 65
Quote:
Originally Posted by StxDangerRanger View Post
You were getting red? i was going nuts! he has an 1989 ranger. some members on this forum weren't even born then! .
touche. all I know is my 98 has a rear axle sensor.
I should learn to think a bit next time before another embarrassment
Reply With Quote
  #20  
Old 03-22-2011
Member
Thread Starter
 
Join Date: Oct 2010
Location: aspers, PA
Posts: 801
hey its alright, we all make mistakes, its just part of the learning process,
Reply With Quote
  #21  
Old 03-22-2011
StxDangerRanger's Avatar
RF Veteran
iTrader: (2)
 
Join Date: Dec 2010
Location: Flat Rock, Mi
Posts: 6,313
Quote:
Originally Posted by 894banger View Post
yeah i actually found out about that little pinion looking gear today, while researching, now i just need to find the tooth count needed and i will be on my way, and i for the last time i would just calculate the difference, but its really ****ed up. anyways, thanks bob, too bad, i found that out before i had a chance to read your post.
I have my doubts on your finding the right tooth count. i've looked before for my truck and there isn't very many out there.
Reply With Quote
  #22  
Old 03-22-2011
RLong31's Avatar
The Ban Hammer
iTrader: (5)
 
Join Date: Jul 2009
Location: Monrovia, IN
Posts: 2,629
You should just FEEL the speed you are going. It's way more accurate than this technology crap and gears and teeth and whatnot.
Reply With Quote
  #23  
Old 03-22-2011
StxDangerRanger's Avatar
RF Veteran
iTrader: (2)
 
Join Date: Dec 2010
Location: Flat Rock, Mi
Posts: 6,313
Quote:
Originally Posted by RLong31 View Post
You should just FEEL the speed you are going. It's way more accurate than this technology crap and gears and teeth and whatnot.
lolwut? I just go as fast as the guy in the fast lane, if i FEEL like i'm speeding. i go by a cop and find out.
Reply With Quote
  #24  
Old 03-22-2011
01RangerEdge's Avatar
Scrambles the DeathDealer
iTrader: (11)
 
Join Date: Jul 2009
Location: Jackson, MO
Posts: 7,598
Quote:
Originally Posted by RLong31 View Post
You should just FEEL the speed you are going. It's way more accurate than this technology crap and gears and teeth and whatnot.
Seriously? The gear driven speedometers are pretty accurate
Reply With Quote
  #25  
Old 03-23-2011
RLong31's Avatar
The Ban Hammer
iTrader: (5)
 
Join Date: Jul 2009
Location: Monrovia, IN
Posts: 2,629
Quote:
Originally Posted by StxDangerRanger View Post
lolwut? I just go as fast as the guy in the fast lane, if i FEEL like i'm speeding. i go by a cop and find out.
Lol, nice.

Quote:
Originally Posted by 01RangerEdge View Post
Seriously? The gear driven speedometers are pretty accurate
No dude, not really. I was kidding, lol.
Reply With Quote
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Calibrate speedometer 01 ranger Wheels & Tires Semi-Tech 6 01-30-2008 12:37 PM
Speedometer reads wrong! SuperKid General Technical & Electrical 7 02-25-2007 11:58 PM
Correcting My Speedometer reallyflyguy Drivetrain Tech 4 02-16-2007 08:25 PM
speedometer conversion? solodos General Ford Ranger Discussion 26 03-17-2005 08:51 AM
digital Speedometer blacknight New Ideas 10 10-04-2004 10:30 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -6. The time now is 06:54 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.