Speedometer Gear help

[Tiretrack]

OK, New to the Jeep world and this forum.
So far I am loving both.

I am in need of help. I have a 84 CJ7 , frame off resoration with Fiber body. Changed the 4c to a 360 and upsized the clutch to match.
Added 31" tires and now the speedometer is off.
I am moving faster than what is stated. I did the math and it appears that I need a 29 tooth gear. Original tranny and gear ratio's. I am making the assumption that its a 3.52.

Any opinions, help and locators for this gear would be a big help.

 

[jarbidge09]

You do not say if you added larger or smaller tires I will assume larger. The larger the tire the slower you speedo will read. I know with the D18 and Dana 20 the speddo gears can not be changed I think it is the same with the Dana 300 . I was told you can change some of the gearing inside the Transfer Case but am not sure what it amounts to it was going to cost me to much so I just live with being 5 mph slower.

 

[LASTCJ786]

No you can change the 81 and up Dana 300 speedo gear go to
4WD.com they have them.

Note: The Dana 18 and 20 use a steel speedo gear. as do the 1980
Dana 300 .

 

[Old Dog]

I got the one for my 83 off ebay.

 

[AGR377]

My speedometer is off by a few mph which i can deal with but it bounces contantly by 5 mph or so it never reads steady. Anything I can do?

 

[CJKrawler]

My speedometer is off by a few mph which i can deal with but it bounces contantly by 5 mph or so it never reads steady. Anything I can do?

That sounds to me more like the cable or the Speedometer. make sure the connection at the tc is good.

 

[Old Dog]

My speedometer is off by a few mph which i can deal with but it bounces contantly by 5 mph or so it never reads steady. Anything I can do?

You could try greaseing it.

 

[73CJ]

When you finally get tired of the speedo being off, think about trying a Nordskog or Dakota digital speedo. It will calibrate with any size tire. Push the program button, drive 1 mile. Hit the button again and 31, 36 or 38.5s, doesn't matter. It's right on!

 

[LASTCJ786]

Try Napa they sell stuff to lube the cable. 4WD.com has a speedo chart.