Which speedo gear?

I knew I was gonna forget to mention that I had 4.10 gears and 35" Goodyear Wrangler MTR's.

Stock 258 w/D300 if anyone cares.

Kevin,

Try the 33.

The charts told me to use a 34 tooth gear for my BFG MT 33x10.50R15 tires (nominally 32.8") and 4.10 gears. The dealers here had none in stock so I tried a 35 tooth gear. It works pretty near perfectly for me. Here's a pic of my GPS reading 99.1 km/h and my speedo needle just a shade higher than 100 km/h:

Is this the chart that told you to use 34?:

Tells me I need 36 teeth whereas 35 is actually best. Tells you to use

34 and therefore confirms that you should try 33.

Steve

Kev> Ok, I've been researching which speedo gear to get for my Dana 300. I came

This probably won't show up, but my chart says 34

G e a r

R a t i o

Tire Diameter (Teraflex #'s listed; Mopar part number: 520676xx, e.g.,

52067628) (Note: The "L" gears do not work in the 231 transfer case.) 35" 33" 32" 31" 30" 29" 28" 27" 4:56 SG35 SG36 SG37 SG37 SG38 - - - 4:10 SG33 SG34 SG35 SG36 SG37 SG38 SG39 SG41 3:73 SG31 SG32 SG32 SG33 SG34 SG34 SG35 SG38 3:55 SG30 SG31 SG31 SG32 SG33 SG33 SG34 SG37 3:07 SG26L SG26L SG27L SG27L SG28 SG28 SG29 SG31

--James

Unless someone convinces me otherwise I think I'll probably go with the 33.

That looks familiar, but it's for a TJ and therefore I assume different.

Should be the same...... "should be"

You know the more correct way to figure it out is; get a GPS and take speed readings from both the GPS and speedo at different speeds. Figure out the percentage off the gauge is. Then remove the old gear and count the teeth. You should be able to get a new gear that is really close.

On another note, I have seen people list their speedo gear sizes and even having 8" rims versus 10" rims makes a difference in the gears.

--James

There were several posts on this, I had the same problem after regearing. I checked on the chart ordered the speedo and was way off. The problem is the tires could say 33" but are infact 32.8.

The only solution is to drive in your jeep at 100KM and use a GPS. To do this you must be on a highway and keep the speed constant. Once your spedometer reads 100km check the GPS. Mine was reading 108 ( I am 8% off). I have 36 teeth speedo.

36 * 1.08 = 38.88 so I ordered a 39 teeth and I am on with in 1KM.

Thanks, I guess it doen't need to be exact for my purposes. I don't drive on the road/highway that much. I guess I can live with it being "in the neighborhood".

So is it the same in any transfer case? I guess I thought the gearing of the transfer case would affect it, and therefore you would need different gears for different types of T/C's.

Someone already posted one for TJ's, and Bills appears to be from a XJ site.

Just don't wanna hassle with getting the wrong thing for my CJ & D300.

Just replaced mine if it helps, D 300, 4.10 gears and 33" tires, 34 tooth gear.

General rule is 2 MPH per tooth. I'm running a 36 w/ 4.10 gears and 33X12.5 tires and it's dead on per my GPS.

Scott