have you regeared?

[zouch]

first, read the instructions so you have some idea of what you're trying to do and how to do it.

i find taking measurements to not be particularly useful. since what i'm trying to do is adjust the speedometer to read accurately, i'll take a drive on the highway with a GPS program indicating speed and see if the J**p speedo is reading high or low, and adjust the tire size entry on the Tazer up or down until the speedo reads correctly. start with some value that's almost an inch smaller than what tire size you think you have (i.e.; 36.x for 37s). yes, it will likely take a few tries.

regearing costs vary depending on who does it and (to a lesser extent) what parts are used, but expect it to be $2-3K.
i would work with a speciality shop experienced with regearing J**ps rather than the dealer; it's not likely anyone at a dealer sets up gears often enough to be in good practice at it, and it seems to be as much art as science.

i don't know of any good reason to use the Tazer to program in invalid values for gearing. what's the point?

EDIT:
note: you should not have your phone plugged into the J**p while you are trying to get your speed check; at least some phones will pick up the speed off of the (inaccurate) speedo in the J**p..

yep its first on the list to do today tazer so I haven’t read the instructions yet cause I’ve only done the TPMS but what tire size do I enter or 37 do I do a chalk test or just enter diameter? and on another note what is the cost of regearing?
Is it better to do it at the dealer so that it’s warranty and if I end up buying an extended warranty that should be covered as well?
Or should I do it at a well qualified shop?

here is another really dumb question but I just don’t know the answer to it
What would happen if you programmed with a taser that you have 488 gears when you really have 456 gears?
It’s only like a 7% difference with the computer. Just read that horsepower and torque down a little bit or something entirely unforeseen happen?

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[3TV]

yep its first on the list to do today tazer so I haven’t read the instructions yet cause I’ve only done the TPMS but what tire size do I enter or 37 do I do a chalk test or just enter diameter?

The instructions for a Tazer tell you to measure the overall height of the tire with the weight of the vehicle on it and at the tire pressure you will be using.

Place a level across the top of the tire and measure from the bottom of the level to the ground to get this measurement.

I personally have found that this method is not completely accurate. When I did this on my 4-door on 40s I found that if I want to drive 80 mph, I have to set the cruise control at 78 mph. On my 2-door on 37s I found that if I want to drive 80 mph, I have to set the cruise control at 79 mph.

I used the same Tazer recommended measurement on both Jeeps. I haven't bothered to readjust the tire size parameters. I think it is close enough.

YMMV, see post above.

 

[Ratbert]

It will alter the shift points in the automatic transmission. Not a whole lot more.

And throw off your speedo.

Note that having the shift points off can significantly impact how it drives.

 

[Ratbert]

When attempting to verify your speedometer with an iPhone, make sure the phone isn't connected to the Jeep. Apparently CarPlay synchronizes the two for some stupid reason.

And no, I don't have an iPhone. Just regurgitating what people with iPhones have said.

 

[grimmjeeper]

And throw off your speedo.

Note that having the shift points off can significantly impact how it drives.

It doesn't throw off the speedo. That's a direct calculation off the ABS sensors and the tire size. Axle ratio never enters that calculation.

For the automatic, the computer needs to know how fast the output shaft is spinning to know when to shift. Some transmissions have a sensor in the transmission to measure that. A lot of them rely on the ABS sensors (used to be the transfer case sensor back in the day). To get accurate data you need the right tire size and the right axle ratio.

The JL may use the same calculation to detect clutch slip. I don't know for sure on that. But other than something like that, axle ratio doesn't impact a manual transmission.

 

[Ratbert]

It doesn't throw off the speedo. That's a direct calculation off the ABS sensors and the tire size. Axle ratio never enters that calculation.

Excellent point. I hadn't considered that detail.

 

[Flip]

Sport with stock gearing. I run skinny 33" tires, I have not regeared and no intentions too. Slow & steady for me or old & slow take your pick.

 

[X35]

Willys XR here with factory 4.56 gears. No intentions to re-gear or ever run tires larger than 35”. I feel the Jeep drives great as is.

 

[Flip]

Willys XR here with factory 4.56 gears. No intentions to re-gear or ever run tires larger than 35”. I feel l the Jeep drives great as is.

That sounds a great set up, lucky.

 

[AmericanPatriot100]

25 sport v6 6Mt stock 3.73s 35s very very rarely do I get to 5th gear. Still see a calculated 20.1mpg computer says 16.9-17.7mpg speedo is off about 7mph. I’d love to regear but I also would love to axle swap to Rubi axles so I haven’t gone down that rabbit hole yet.

 

[GabeBoyTheGreat]

25 sport v6 6Mt stock 3.73s 35s very very rarely do I get to 5th gear. Still see a calculated 20.1mpg computer says 16.9-17.7mpg speedo is off about 7mph. I’d love to regear but I also would love to axle swap to Rubi axles so I haven’t gone down that rabbit hole yet.

Pretty sure the stock gears are 3.45s.

 

[AmericanPatriot100]

Pretty sure the stock gears are 3.45s.

Yeah that’s my bad. I put 3.43 and meant 345 it looked wrong so I switched it to 373!

 

[gato]

You need to ask in the poll manual vs auto. With the auto there is little reason to regear. The manual V6 is a completely different story.

 

[wanderer]

success without regearing i am seeing 8th after installing my tazer that being said it is not as zippy as with 35s and 456 so i may go to 488 next step suspension ughh this is getting just empty every pocket and sesrch the couch for spare change

 

[wanderer]

if you regear would you do it through the dealer to preserve your warranty? would an extended warranty cover a regear performed by a dealer?
what if you went through a shop ? would a jeep that has new gears be covered for an engine issue if the regearing was done by s shop?

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