I have a 2001 TJ and a year ago added larger tires and a new speedometer gear. When I did this, I thought a heard a very subtle noise from the area of the new speedo-gear, but so subtle, I didn't think anything of it. A year later, the noise isn't bad, but less subtle than it used to be. I'm thinking I have a bad speedo-gear, but don't want to spend ~$70 to test this idea out. I'm wondering if it's possible to take the gear out and see if the noise goes away. ... in other words, if I take the speedo gear, are there any issues besides not being able to see how fast I'm going?
Will lack of speedo gear harm anything?
- Thread starter JeepSki11
- Start date
SteelHeadz
Super Moderator
On an 01 TJ, the speed sensor is a direct input to the PCM/TCM and ABS. The TCM needs the input from the speed sensor for shifting reference along with the engine RPM that's from the PCM IF IT'S AN AUTOMATIC.. The ABS also uses this signal to determine ABS engagement if in fact the parameters are met for the ABS to engage, Speed Vs. Pressure. This also is in referrence to the ABCM(Airbag control module). When the parameters and thresholds are met in an event of impact, Depending on the vehicle speed, the Airbag which has two deployment circuits, will deploy at a certain rate Vs. speed. So to answer your question, It is critical but not readily seen and there are subsequent consequences if you ignore it's function other than just telling you how fast your moving. For testing and diagnostic purposes, you should be okay, but not in a long term disable.
SteelHeadz
Super Moderator
You should be fine.. Keep a cover on it when you take it out.
Bounty__Hunter
Super Moderator
You will be fine for a test drive. Pull the speedo sending unit out, remove the gear, and replace the sending unit into the transfer case to seal it up.
Your check engine light will likely come on, but you will be fine.
Your check engine light will likely come on, but you will be fine.
Crazy4diesels
New member
If the noise came with the new gear you might not have the mesh right. Did you turn the speedo gear housing to line up with the correct number of teeth? - John
Bounty__Hunter
Super Moderator
The speedo gear is plastic, I doubt it can generate enough noise to hear while driving. I'd bet your problem is something else.
jfrabat
New member
X2; I even had my gear fall into the transfer case (stupid me did not rotate the housing to the appropiate side) and it did not make any grinding noises...
