Topic: Speedometer Gears

[Jeffy]

Well, I'm on the look out for a 39T gear.  I can't believe how much these things have jumped in price.  When I bought my 35T and 37T, they were around $15-18 at the Dealership.  Now they're $118.  You can find them online for around $39 but I think that's still a hell of a lot.  Especially since they're imported from Taiwan.  Anyone have one they want to trade or sell outright?  It need to be a 4.5" long shaft and not the 2.5" short shaft the TJ's use.  The part number is #52068061.

[aw12345]

Good luck finding one, the 39 and 40 tooth gears are pretty hard to come by.
The 50 dollar converter box might be a better bet in the long run

[Jeffy]

Good luck finding one, the 39 and 40 tooth gears are pretty hard to come by.
The 50 dollar converter box might be a better bet in the long run

I've seen a few places with them for $39.  There is another company, PPR, that makes them.  I think it's the actual company that makes them or else imports them from Taiwan.

Here's the part number for the 39T - PPR-3091-0639L

The cheapest electronic option is Dakota Digital.

http://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=126/category_id=287/home_id=59/mode=prod/prd126.htm

[aw12345]

I know how much the are, 2 gear changes or tire changes and the dakota unit paid for it self

[Jeffy]

I'm just surprised the price jumped $100.  I'll probably just get the right gear.  I don't see myself getting it regeared or changing tires anytime soon...  maybe.

[Mozman68]

I still have to correct the wiring on my Dakota Digital unit....I did notice that at some point they did update them so that once it is wired in you simply hit "up" or "down" to correct the speed...I just need to wire into my new sensor and too lazy to crawl under there and do it.

[sharpxmen]

I still have to correct the wiring on my Dakota Digital unit....I did notice that at some point they did update them so that once it is wired in you simply hit "up" or "down" to correct the speed...I just need to wire into my new sensor and too lazy to crawl under there and do it.

you can always do it in the engine bay where the wires join the main wiring harness (not sure where that is on your TJ but if I were to do it that would be my choice rather than going with another set of wires all the way to the sensor).

[Bounty Hunter]

I've got a whole bunch of speedo gears, but the closest I have to what you need is a 36t or a 41t.

Have you checked with www.tacomaspeedometer.com ?

[Jeffy]

I've got a whole bunch of speedo gears, but the closest I have to what you need is a 36t or a 41t.

Have you checked with www.tacomaspeedometer.com ?

Sent them an email.  I have a 35T, 37T and a 41T.  Currently I have the 41T installed and it's about 4-5MPH off at 65 mph.  I'm pretty sure the 37T was about the same.

[sharpxmen]

Sent them an email.  I have a 35T, 37T and a 41T.  Currently I have the 41T installed and it's about 4-5MPH off at 65 mph.  I'm pretty sure the 37T was about the same.

1/41.....65mph
1/37.....72mph

[Jeffy]

1/41.....65mph
1/37.....72mph

So you're saying it should be correct with the 41T?

[neale_rs]

It means that with the 37 it would only be off by 2 or 3.

[sharpxmen]

So you're saying it should be correct with the 41T?

i'm saying that if now it shows 65mph with 41T at the same speed with 37T will be showing 72mph (neale got it right).

if you meant that at 65mph real speed and with 41T the speedo displays 60mph then with 37T at the same real speed would display 66.5mph

[Jeffy]

I had both in there and both were off but on the other side of correct.

[sharpxmen]

I had both in there and both were off but on the other side of correct.

not saying it's correct, just gave you the impulse equivalent speeds based on what you provided. Not sure what the stock size tires you had initially on your jeep but if i take 28'' as stock and 33 what you have now at 65mph real speed (and displayed with 28'' stock tires) with 33'' tires would display 55mph (with stock gears) - you however have 4.56 gear ration compared to 4.10 so that would make the speedo display 61.3mph (so that is about 4mph lower than real speed and consistent to what you are reporting) - at this point swapping the 41T with the 37T would make the speedo display 68mph

so according to my math in your configuration at 65mph real speed with 41T = 61mph, 37T=68mph (-4/+3) - that is based on 28'' stock tires and 4:10 stock gears (if different then the numbers will be different) - seems to be in the same ballpark to what you were seeing before, 37T is a little bit closer to reality but still off and not much of a difference

Also, different speeds result in different mph offset, percentage based would be the accurate way to measure it (same at any speed).

Sounds like the dakota digital would be the best option if you plan to play around with the tires in the future, one time payment and call it a day