Just recently put 17" moabs on my 00' xj and a RE track bar.

Issue:
When driving at 20 MPH, as soon as I let my foot off the accelerator, the speedo jumps to 70 mph. It didn't do this before the track bar installation. WTF?

 

No one has any thoughts?

 

I just had to replace a part on tranny did the same thing. It's a speedo module sensor. Was like 50 and that fixed mine

 

How did you diagnose this issue? Is there any rhyme or reason to these speedo failures?

 

What had happend is I took it to a local trans shop to have slave and master put in . I got it back and noticed speedo was messed up it would go up to bout 20 then bounce around so I room it back to the shop and they found the sensor was bad and replaced it . Doing fine now . I have never heard of it before so I learned something new

 

Anyone else with this issue?

 

mine was way off but not bouncing because the speedo gear was not set up for the axles in my 2000 when i dropped in a 4.0/ax15/231

put in the original gear from the 2000 and now its only a few mphs off

i have the extra module for a 231 if you want to buy it...

 

Jomps,
I appreciate the offer and I am seriously considering it. I am unsure if mine definitely needs to be replaced though. Is this the only troubleshooting technique? If it bounces it must be bad?
I will pm you in a few days and we can work out the details. Thanks.

 

idk how to test but if its not staying accurate then the sensor module is bad or there is another reason the computer thinks its bad...goodluck

 

your connection to the housing may be broken as mine is and if i hit a bump the guage goes crazy. if the guage is not accurate you need to get a new speedo gear to put in the housing and it will work fine and they are easy to replace

 

gear is fine unless teeth are broke...

 

the title of this thread scared me

and no i have no usefull info just glad this thread isnt full of dudes in speedo's

 

Uhhhhhh........thanks for your contribution?
Now that I think about it, my speedo does feel tight! Maybe that's why I'm losing pressure and there is an awful smell