-   Wrangler General Discussion (
-   -   Rubicon--No speedo gear? (

3X4X4 01-14-2013 06:48 PM

Rubicon--No speedo gear?
Why does the Rubicon (06 TJ) use a Hall Effect speedo signal instead of a gear? I do not understand?

I see there are a number of electronic methods to correct the speedo by installing an electronic box. Yellow Box etc. Is this the best way to go or is there some more comprehensive means of dealing with this?

My concern is shift points and other engine info--my Rubicon is an automatic.

Thanks a ton.


biffgnar 01-14-2013 07:43 PM

22 Attachment(s)
I believe it is a matter of TC size. The 241 is a bigger case than the 231. The TJ rear driveshaft is already very short. By going to a tone wheel you can keep the driveshaft longer. Many of us with 231s end up converting to a tone wheel when we do super short slip yoke eliminator (not something the 241 requires). Personally I use a Blue Monkey Speedo Healer but they are all generally the same as to modifying the signal between the TC andthe PCM.

Shift points on the 42rle are just annoying. No way around that. Best thing to do is keep the signal accurate through electronic adjustment. Results will not thrill you but they will be better than not correcting.

3X4X4 01-14-2013 08:56 PM

Thank you for the answer, that makes sense to me. So if I install one of the electronic corrector boxes I can adjust my speedo correctly and it may also help with the shifting?

My Rubicon seems to have plenty of power, I suspect it has been regeared already to suit the 35X12.5X15 tires and wheels that were installed, it does not feel sluggish at all but my speedo is way off, to much to do easy mental correction and of course it varies with speed. I need to get it corrected and hopefully it is simply a matter of a 100 dollars (plus or minus) e-box. A little more than a gear swap in dollars but it might actually be easier to swap wheel and tires sizes and still correct the speed and data signal?


Thank again.


3X4X4 05-11-2013 09:30 PM

My Yellerbox installed with plug and play harness:


rubicon17 05-13-2013 09:28 AM

i just installed a speedohealer from blue monkey last week, took like 5 minutes total including the programing and it made a big difference, i only have 33s, shift points are back to stock and i can actually get on the freeway and cruise instead of having to run the crap out of it. well worth the money. i had to add 9.1%, i wonder if the trans would shift any difference if i made the speedo read faster than what im going? like +15 or 20%?

jay-h 05-18-2013 04:55 PM


Originally Posted by 3X4X4 (Post 14790292)
Why does the Rubicon (06 TJ) use a Hall Effect speedo signal instead of a gear? I do not understand?


Speedo gears are pretty much extinct. Virtually all vehicles use either a sensor on the transmission or at the wheels.

3X4X4 05-18-2013 07:04 PM

double post

3X4X4 05-18-2013 07:06 PM

Thanks Jay-H but I done figured it out since January, ;). These electronic boxes, Speedo Healer, Yellerbox etc. really work very well. It is possible to change gearing, tires etc. and custom program the unit in a few minutes. Auto transmissions benefit greatly as the shift points are back where they belong. You can run winter tires, summer tires and in a few minutes change your program. It took me about 30 minutes to install including the RTV and the Radio Shack box. Then two test drives to dial it in. I would not want to do it every week but if you seasonally change tires or go to a special off road tires for an event, this is the e-ticket.


The time now is 11:51 AM.

Powered by vBulletin Version 3.8.8
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.