Novak Conversions Jeep Wrangler TJ radiator

Weird speedometer issue

Chemrock

New Member
Original poster
Joined
Sep 26, 2024
Messages
2
Location
Cedar City, UT
I've seen lots of speedo issues, but I haven't found one for my situation yet.

I have been running a 32 tooth gear and my speedometer has been dead on. Been that way for months. I just installed a SYE kit with a new rear driveshaft. I triple checked to make sure the gear housing is indexed properly, inspected the teeth, made sure I installed the blue gear on the new SYE shaft and both snap rings are there, made sure the electrical connector is good and tight...

Here's the problem: My first test drive after installing everything didn't show a speed until I hit about 15mph, then it suddenly jumped up and bounced around a bit before settling down. It reads now, but it's not accurate anymore. It shows about 5mph slower than actual speed at 45mph. The other weird part is that the speed bounces +- 5mph while I'm driving a steady speed. I even tried cruise control, and it wreaked havoc. The throttle was surging because it was getting fluctuating speed readings. The fluctuation is constant.

Does anyone have an idea of what would cause this? The only thing different I can think of is that new SYE shaft with the new blue gear. But why would that cause these new issues when they didn't exist before? And throw off the accuracy?

Thank you
 
I had a similar problem several months ago when I replaced the speedometer gear to calibrate speed after changing tire size.
What I discovered was the O ring has split and was interfering with the mesh of the gears.
Remove the speed sensor housing and check the O ring to ensure this hasn't happened to yours.
 
Last edited:
Update:
I drove my Jeep again today and everything returned to normal, like it was never having problems. Not sure what that was about, but it seems to be fine now. Thank you for taking the time to read about my weird ghost of a problem!
 
Novak Conversions Jeep Wrangler TJ radiator