speedo calibration after lift

jeeprookie

New member
Anyone know anything about the Superlift Truspeed calibrator module?
I want to correct my speedo after I put on 33's and I saw this on a site.
 
The electronic calibrators just correct your speedometer. If you change the speedo gear, your computer will know your correct speed.

It is really a complete waste of money to get the near $200 unit when you can easily install a cheap gear.
 

TwistedCopper said:
The electronic calibrators just correct your speedometer. If you change the speedo gear, your computer will know your correct speed.

It is really a complete waste of money to get the near $200 unit when you can easily install a cheap gear.

Yeah, I had heard that before (probably here), but wasn't 100% sure, so I didn't say it......5 minutes and $10 to $25 for a speedo gear swap.
 

Where is the speedo gear located? Planning on lifting and going with bigger tires soon, so might as well ask now.
 
Re: RE: Diff Questions

SenorCole86 sig:
1980 CJ-7 Renegade
(In the middle of a LONG restoration)

You might as well change that to :
1980 CJ-7 Renegade
(In the middle of a NEVER_ENDING restoration)
 

where can I get this $12 part..? anyone have a link.. I just got 33's and I would like to know how fast Im really going
 
I bought mine from the stealership for $21. There were two transmission places in town that sometimes have them used for around $5, but they didn't have any like I needed.
 
Sparky wut gear ratio is in ur YJ? Im not exactly sure wut gear ratio mine is. Its a '93 YJ with a 4.0L. Im doing a lift and tires to 31x10.5 and I'm definitely doing this.
Mike
 

Radio doesn’t work missing fuse

Good question, raptor....I don't recall! For some reason 4:11 comes to mind, but I really don't know. Cross checking the chart I used to figure how many teeth on the speedo gear I needed, it looks like I used the 4:11 (4.10:1) gears. Different charts give slightly different recommendations for number of teeth, though, and I guessed at 36. It's close, but I really think I needed to get 37 instead. Someone told me here that most of the YJ's in '94 had the 4:11 gears, but there were some that were different. There is supposed to be a tag on the diff that tells what they are, but mine either wasn't there or I couldn't read it, I don't remember which.
 
Most YJ's, regardless of year, generally follow these guidelines for axle gear ratio:
2.5L with manual: 4.11
2.5L with auto: 3.73
4.0L or 4.2L with manual: 3.07
4.0L or 4.2L with auto: 3.73

This isn't a steadfast rule, as with everything else jeep, but generally holds the most true for the 2.5L jeeps. The 4.0L and 4.2L jeeps also had some 3.55 and 3.73 mixed in, whatever Jeep decided to put in.

www.sierrajeep.com/speedome.htm
www.stu-offroad.com/speedo/speed1.htm
 
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