Speedometer isn't reading after changing speedometer gear

Moseley81

Moseley81

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Broxton,Ga
Hey everyone first off Happy Father's Day to all the dads.
Ok.. so i moved up tire sizes to a 33' and i changed the speedometer gear to a 31 tooth which according to the chart is the right size for 3.73 gears and 33's. My problem is now my speedometer isn't reading and its fully seated. Ive adjusted it twice and its its still not reading and its fully seated. Do i just need to keep adjusting it or is there a step im missing? Thanks for any help yall can give me.
 
Yea the old one worked it was a 36 tooth. I pulled the old one out of the sensor and put the new one back in. It was the same length. Just different color and small in diameter.
 
If you rotated it to the new number on the speedometer housing and it still doesnt work, you may have a defective gear. I bought one that worked for 2 days then started dropping off speed with the needle bouncing. I put the old one back in and it worked fine.

I had no gear teeth missing on the new one so I sent it back. I think it wasn't connecting to the speedometer shaft correctly.

I haven't bothered with a new one, because I'm only 3-5mph fast. If I drive at the speed limit I'm not speeding too much and I stay up with traffic.
 
The only things that come to mind would be to ensure the speedometer gear metal shaft snaps into the speed sensor housing properly and the harness connector is snapped into the sensor housing. You might also check the connector pins for oxidation.
 
InOmaha said:
If you rotated it to the new number on the speedometer housing and it still doesnt work, you may have a defective gear. I bought one that worked for 2 days then started dropping off speed with the needle bouncing. I put the old one back in and it worked fine.

I had no gear teeth missing on the new one so I sent it back. I think it wasn't connecting to the speedometer shaft correctly.

I haven't bothered with a new one, because I'm only 3-5mph fast. If I drive at the speed limit I'm not speeding too much and I stay up with traffic.
Click to expand...
Which way is the numbers for the speedometer housing supposed to be pointing?
 
Here...

image.jpeg
 
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On the speedometer sensor for my '98 XJ 4.0L there were number groups for orientation of the housing depending upon the speedometer gear you were using, but on my '01 TJ 4.0L the numbers are in a different location. There are notches for the lock down clamp that holds the speedometer housing into the transfer case output shaft housing.
You can rotate the housing in 90* increments in relation to the lock down clamp,
 
The usual reason for this issue is not having rotated the housing far enough for the new speedometer gear to engage its pinion gear underneath. Even when I've lined the numbers up I've often had to go back in and fiddle with it by rotating it a bit more until it starts working.
 
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