Rubicon question

"Troy" <troy@ .> wrote in message
. ..
> He is going to have to buy a speedo gear from the dealership, according to
> the ring and pinion gear he already has. I used this link to figure mine
> out: http://www.raingler.com/tech/speedoChart.asp
>

There is no need to buyit from the dealership, any speed shop should carry
them.



> Funny thing is that the parts guy at my dealership said I'd have to
> reflash my computer but I bought the proper speedo gear anyway (he said it
> wouldn't work). It does.
>
> I really think its a bad idea not to change the gears with that size tire,
> might be doable with 3.73 but my jeep had 3.07 with a manual transmission
> when I went to 33's and it was so bad I didn't drive it until I could buy
> the gears.
>

I agree with you, BUT the Rubi comes stock with 4.10 gears anyway, so it may
work out okay. I stick to 4.56s if I was doing it, so the 4.10s won't be too
bad.

Someone in this group said the Rubicon automatically recalibrates
speedometer for tire size, like it may have an axle height sensor.
God Bless America, Bill O|||||||O
http://www.billhughes.com/

Rich wrote:
>
> I've got a neighbor who has a Rubi. 2005 I think. He's getting ready to lift
> it and put 35" tires on without a gear change. (not a choice I'd make but
> non-the less). He's wondering what he can do to recalibrate the Speedo
> without going to the stealership. I'd know what to do if he had a CJ. My
> guess is he needs a computer reprogramming. True?
> Thanks
> Rich

Jeff, the Rubicon 4:1 T- case IIRC doesn't use a speedo gear, it uses an
induction pickup sensor on a tone ring inside the case.

"Jeff Strickland" > wrote in message
...
> He will do the same thing you'd be doing -- switch the gear in the speed
> sensor.
>
> He ought to be able to find the speed sensor on the output of the tcase in
> essentially the same place as on your CJ. The sensor spins around because
> it is mounted on a gear that mates to something inside the tcase. Swap the
> gear to recalibrate the speed sensor.
>
>
>
> "Rich" > wrote in message
> news:XwIPf.1602$ky1.188@trndny06...
>> I've got a neighbor who has a Rubi. 2005 I think. He's getting ready to
>> lift it and put 35" tires on without a gear change. (not a choice I'd
>> make but non-the less). He's wondering what he can do to recalibrate the
>> Speedo without going to the stealership. I'd know what to do if he had a
>> CJ. My guess is he needs a computer reprogramming. True?
>> Thanks
>> Rich
>>
>

I've heard that before too but I can't imagine how it would do that unless
there is some kind of sensor, I'd guess a GPS module.

"L.W. ("ßill") Hughes III" > wrote in message
...
> Someone in this group said the Rubicon automatically recalibrates
> speedometer for tire size, like it may have an axle height sensor.
> God Bless America, Bill O|||||||O
> http://www.billhughes.com/
>
> Rich wrote:
>>
>> I've got a neighbor who has a Rubi. 2005 I think. He's getting ready to
>> lift
>> it and put 35" tires on without a gear change. (not a choice I'd make but
>> non-the less). He's wondering what he can do to recalibrate the Speedo
>> without going to the stealership. I'd know what to do if he had a CJ. My
>> guess is he needs a computer reprogramming. True?
>> Thanks
>> Rich

That said, I am skeptical.

"L.W. ("ßill") Hughes III" > wrote in message
...
> Someone in this group said the Rubicon automatically recalibrates
> speedometer for tire size, like it may have an axle height sensor.
> God Bless America, Bill O|||||||O
> http://www.billhughes.com/
>
> Rich wrote:
>>
>> I've got a neighbor who has a Rubi. 2005 I think. He's getting ready to
>> lift
>> it and put 35" tires on without a gear change. (not a choice I'd make but
>> non-the less). He's wondering what he can do to recalibrate the Speedo
>> without going to the stealership. I'd know what to do if he had a CJ. My
>> guess is he needs a computer reprogramming. True?
>> Thanks
>> Rich

No, the Rubicon has no way to self-calibrate its own speedometer. The
dealer must reflash the computer but I don't think they have a way to
reflash for any tire as large as 35".

And the Rubicon's performance with its 4.10 axle ratio with 35" tires
and the 5-speed or 6-speed tranny would absolutely suck big-time.
Performance would not be so bad with that combination if it had an
automatic though.

Jerry

L.W.(ßill) Hughes III wrote:
> Someone in this group said the Rubicon automatically recalibrates
> speedometer for tire size, like it may have an axle height sensor.
> God Bless America, Bill O|||||||O
> http://www.billhughes.com/
>
> Rich wrote:
>
>>I've got a neighbor who has a Rubi. 2005 I think. He's getting ready to lift
>>it and put 35" tires on without a gear change. (not a choice I'd make but
>>non-the less). He's wondering what he can do to recalibrate the Speedo
>>without going to the stealership. I'd know what to do if he had a CJ. My
>>guess is he needs a computer reprogramming. True?
>>Thanks
>>Rich

--
Jerry Bransford
PP-ASEL N6TAY
See the Geezer Jeep at
http://members.cox.net/jerrypb/

That is the combo I'm currently using. While not ideal, I'm not a rock
crawler so with the auto trans it is satifactory. There has been nothing
that 4LO didn't get me out of.

tw
__________________________________________________ ___________________
2003 TJ Rubicon * 2001 XJ Sport * 1971 Bill Stroppe Baja Bronco

"There is a very fine line between 'hobby' and 'mental illness'."

Pronunciation: 'jEp Function: noun Date: 1940

Etymology: from g. p. (G= 'Government' P= '80 inch wheelbase')
A small general-purpose motor vehicle with 80" wheelbase, 1/4-ton
capacity and four-wheel drive used by the U.S. army in World War II.
__________________________________________________ ___________________

Jerry Bransford wrote:
> No, the Rubicon has no way to self-calibrate its own speedometer. The
> dealer must reflash the computer but I don't think they have a way to
> reflash for any tire as large as 35".
>
> And the Rubicon's performance with its 4.10 axle ratio with 35" tires
> and the 5-speed or 6-speed tranny would absolutely suck big-time.
> Performance would not be so bad with that combination if it had an
> automatic though.
>
> Jerry

i have 456 with 35's and bought a new speedo gear at the dealer it was only
10 bucks



"Rich" > wrote in message
news:XwIPf.1602$ky1.188@trndny06...
> I've got a neighbor who has a Rubi. 2005 I think. He's getting ready to
lift
> it and put 35" tires on without a gear change. (not a choice I'd make but
> non-the less). He's wondering what he can do to recalibrate the Speedo
> without going to the stealership. I'd know what to do if he had a CJ. My
> guess is he needs a computer reprogramming. True?
> Thanks
> Rich
>
>

Yep but again, that won't work with a Rubicon that does not use a
speedometer gear.

J. Sprauer wrote:
> i have 456 with 35's and bought a new speedo gear at the dealer it was only
> 10 bucks
>
>
>
> "Rich" > wrote in message
> news:XwIPf.1602$ky1.188@trndny06...
>
>>I've got a neighbor who has a Rubi. 2005 I think. He's getting ready to
>
> lift
>
>>it and put 35" tires on without a gear change. (not a choice I'd make but
>>non-the less). He's wondering what he can do to recalibrate the Speedo
>>without going to the stealership. I'd know what to do if he had a CJ. My
>>guess is he needs a computer reprogramming. True?
>>Thanks
>>Rich
>>
>>
>
>
>

--
Jerry Bransford
PP-ASEL N6TAY
See the Geezer Jeep at
http://members.cox.net/jerrypb/

http://www.dakotadigital.com/index.c...rod/prd126.htm

Several folks on the rubicon owners' forum have used this solution and
say it's dead on compared to GPS speed.

The computer is capable of being properly calibrated for 35's w/ stock
gearing by the dealer's computer too, but it's not possible with
numerically higher gear ratios. For what you'd pay them, though, the
Dakota solution is probably a better deal overall since if he ever does
change gears, he just needs to reprogram it again.

-jd

Rich wrote:
> I've got a neighbor who has a Rubi. 2005 I think. He's getting ready to lift
> it and put 35" tires on without a gear change. (not a choice I'd make but
> non-the less). He's wondering what he can do to recalibrate the Speedo
> without going to the stealership. I'd know what to do if he had a CJ. My
> guess is he needs a computer reprogramming. True?
> Thanks
> Rich