Need experts out there to guide me in a good direction before I spend lots of $$ on what might be a simple problem. Odometer is off by 1/10 of a mile for every mile driven and speedometer is off by up to 10 miles per hour at HIGHER SPEEDS. Lower speeds and my speedometer is accurate around 35mph anything higher and I start to loose accuracy. Thought I would change the speedometer cable but why would I have accuracy at lower speeds and not higher speeds if it was a cable? As far as the odometer my tires are sized right according to door VIN tag and that shouldn't be throwing odometer off. Thought about changing out cluster on dashboard. The last thing I could do is change out or check gear ratio in rear axle. Would that throw both odometer and speedometer off? So money could be spent in alot of areas before I find the problem. (1994 Ranger 6cyl. 4.0L 4x4)

 

gear and tire size will throw it off, but if they haven't been changed, a trans swap could have done the same as well. i don't think there is anything wrong with the cluster, so no need to replace it. your speedo and odometer work together, off a speedo cable. where your speedo cable goes into your trans, there should be a plastic gear that drives the cable. this gear is replaceable with different sizes to correct speedo problems. but for the amount you are off, i probably wouldn't even worry about it. you can pull the speedo needle off and reset it at a higher speed if it would make you feel better. i use my gps unit on a long stretch of interstate to set my needles.

 

Yours is a manual speed-o, one that has a cable directly to the trans-t/c.
Only things, IMO, that can cause you problems would be something mechanical.
The Cable or gears, not much chance of them being broken or damaged or tire/diff gearing.

If you haven’t chg’d the gearing in the diffs or tire size, then the first thing I would do is look for another speed-o, either the separate unit or a Cluster and try it out.

I do not believe there is an electronic Speed-O for 94, so the computer thing is out, has to be mechanical. Just for grins consider lubing the cable, pull the Cluster, disconnect the speed-o cable from the cluster and put in some lube, maybe a rust-buster type but not too much but enough.

After that if the readings are off do the cluster change and see.
Next thing… how worn are your tires.

 

How would I know which gear to replace on the speedometer cable if there are different sizes?

 

i don't know for sure. they are color coded to the size/number of teeth. i think i have seen it on another ranger site.

http://therangerstation.com/tech_lib...peedogear.html

 

I do not know for sure, the trans gears can be looked at and replaced with OEM replacement but in the speed-o, you will need to disassemble and look at all the gears and see what is going on.
Trans Gear can be changed but usually when tire size or diff gearing is altered.
Speed-O Gears, usually replacement of the Cluster is in order unless you have time and patients to take apart and look-see.

The question is… do all speed-o’s have this problem but everyone else ignore it.

Lube up the cable first and see what happens.

 

I will look and see the next time I have a weekend off. Thanks all you RANGER nuts for the guidance!!

 

Hey, I am having this same problem with my 98, 4x4, 4.0L but I notice that the speedometer and odometer are off at all speeds. Let me know if you figure anything out.