Least Expensive way to Recalibrate?

[Lunentucker]

Hmmm.... I didn't know about the centering the steering wheel option. That's awesome. But then again, the app probably has a lot more things since it's updated. Good information!!!

I'm not sure I'd trust that one.
I was messing with displaying my steering angle in the dash display the other day while driving, and there's a good bit of movement, in both the steering wheel and the tires, before it reports a degree of angle change.
Assuming the JScan reads from the same source, I wouldn't rely on it to heavily for alignment setup.

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[dmwphoto]

Jokes and humor are in the O thread.

Done right - the same folks that say "your winch is draining your battery" while they stand next to a big red switch that says OFF, right next to the battery.
The same folks who say "I fixed it" and they move the winch ground cable from the battery negative to a small stud on the fender - the same stud the battery negative is connected to.
The same folks who use an impact wrench to torque wheels ( and the list goes on)

Dealership may charge $100. Many have a minimum (even if you happen too accidentally find one that does it right). That minimum could be 1 hour, could be 1/2 hour, but it's likely not far from the cost of a DIY device.

Scenario 1 - dealer does the tire size recalibration. They look at the tire, hmm, a 33, and now you have two possibilities:
A. Dealer looks up the tire and sees the diameter posted is 32.8" and that's what they plug in. (gets you close if lucky)
B. Dealer measures tire as it sits on the truck and plugs it in (more correct)
And for each of those you have two possibilities -
tech uses his phone as GPS and checks accuracy
tech says "done, I plugged in what they told me, good enough"
I'd bet dinner on "I plugged in the number I found, I'm done" and the assistant drives it out and parks it and they call you it's done.

Scenario 2 - you purchase the software and cable needed to DIY. You now own the equipment. It costs only slightly more than the dealer's fee - sometimes about the same.
you plug in the numbers, take it for a drive and compare with GPS and it's off a bit, you go back, tweak the number, drive it again - perfect (well, within any reasonable figure anyway)

And then you drive it a year or two and decide now you want a tire change - any one of many reasons from a list of possible reasons - want to lift it and get bigger for climbing up the side of the Grand Canyon and crossing the Colorado River, or mudding with friends, or whatever.

With 1. you go back to a dealer, pay again, roll the dice as to is it A or B
With 2. you own the stuff, you don't pay a penny extra.

Or, 2 years later you decide you want a Toyota Prius instead and sell your JT - you can now sell your bypass cable, extension cable, and BT adapter for about half of what you paid and get a bunch of your money back.
With 1, the dealer has your money.

If you own the software and hardware, you can also do much much more - got an odd misfire, decided to add power locks or passive entry or change to LED lighting?
Well, you could pay a dealer to make those changes, or - you could already own everything you need to do it yourself.

I just can't see paying the big bucks and hoping you get a tech who actually plugs in correct numbers.
On the other hand - does anyone who takes their Jeep to a dealership to have the tire size change ever even both to LOOK to see if they did it right?
My bet is that half of those Jeeps done by a dealership are wrong if you compare the odometer and speedometer to fact.
Are they going to spend time? Or will they look at some chart, plug in a number and drive it out and collect your money and never bother to see if their number matches the reality.
I've looked up a fair number of tires and sometimes find that one site will say a tire is xx diameter and other have a different number..........

I guess I had to smile when I saw "done right" in the same sentence as the word "dealer".

If you will never do another thing to that Jeep, will never do anything else at all, don't care to ever reset any codes, read any codes, do any other diagnostics, will never change tires again and maybe not even keep it that long - the dealer may be worth it. Maybe - but to assume it will be done right, not so sure I'd go there as you can bet they won't do any more than go in, plug in a number, save it, and disconnect their equipment. It's up to you to test it and see if what they put in matches reality.

If I ever decide Jeep sucks, this is the last Jeep I'll ever own, sell 'em all, buy an Escape as a true off-road vehicle, I can at least recover some of my money selling the bypass cable and other stuff. You have an asset in those things, and it's an asset where the value keeps going up in the eyes of Jeep people (and even on Amazon - man, I'm glad I bought when I did.)



The problem comes in by size definition. The system stores it as a rolling circumference. The app or device translates that to a diameter.
So which diameter do you use? Is it a 33" tire? No, depending on the tire, brand, etc. it's likely a 32. 7 to 32.8 or similar while standing free.
But on the truck it's likely a 32.6
Took me two entries to get the odo and speedo to match GPS and reality. Nothing I looked up and plugged in was the exact number. I got it close, figured whether I needed to go higher or lower and changed the number a bit, tried it - spot-on.
Plus - if you change your mind in 2 years - you can go in and do it again for FREE. Dealer won't do it again for free. Sell the Jeep? Then sell the equipment and get some of your money back. Sell your Jeep? Can't go to a dealer and ask for money back because you sold your Jeep.

look at all the people messing things up by using tasers and J scan and end up with other issues. Not everyone has your background. I trust my dealer to do things right. So far no issues for me. I have 40 years of automotive service background in dealerships.
IT is my opinion and I stand by it.

 

[Toro34]

I am looking to go to 37" tires, and no other crazy changes. What is the least expensive way to recalibrate the speedo, etc for the new tires? Just seems excessive to spend $200+ for anything I have seen on a device I'll use for the one change. Any other options?

I wouldnt look at it as 'one time' thing. Tires are not all 37" in size. Once on the vehicle they are usually closer to 36.5'

If you decide to try a different company on your next set, their tire sizes will most likely be different. ie BFGs run small, usually 35.5' for a 37. So you should recalibrate again.

Most of the tools mentioned above (I use a Tazer) will give you additional options for troubleshooting and additional changes to the vehicle. TPMS settings, switching lights from halogen to LEDs, and some convenience features like turning the passenger seat heat on during remote start, or activating the rear camera with turn signal, there's lots of situations where you need to reprogram.

37s are expensive, in the grand scheme, saving up another 200 on a 2500 purchase is worth it in this case

 

[ShadowsPapa]

look at all the people messing things up by using tasers and J scan and end up with other issues. Not everyone has your background. I trust my dealer to do this things right. So far no issues for me. I have 40 years of automotive service background in dealerships.
IT is my opinion and I stand by it.

IMO your points are valid. I'd trust some techs to do it - the ones that did my VIN update on the 2020 when I installed passive entry and asked for a couple of other things, I'd trust them totally to get it right. They did a great job on the 2020's steering gear swaps.
But then when I went back for low battery voltages (which I ended up fixing myself by doing what I should have done to begin with - reset IBS, charge each battery, done) I got the "your winch is draining your batteries and I wanted to ask them to prove they made it through high school shop class. Switch - OFF - what part of "dead circuit" don't you get, can't drain battery if the power is disconnected.

You have to know your dealership, figure the tech you get THAT day knows more than the tech I got on the battery thing.
You have to find out what that dealer charges, and then be honest with yourself- is it a "I really want to do it but electronics scare me" or "I've done this 100 times, it's stuff you do in your sleep".
Everyone wants to - only a few should.
Sound about right?
To each their own skill.

Some of the stuff I get into my shop that others have worked on totally supports your points.........

BTW - shop rates here approaching $200/hour.

 

[tysongladiator]

Jokes and humor are in the O thread.

Done right - the same folks that say "your winch is draining your battery" while they stand next to a big red switch that says OFF, right next to the battery.
The same folks who say "I fixed it" and they move the winch ground cable from the battery negative to a small stud on the fender - the same stud the battery negative is connected to.
The same folks who use an impact wrench to torque wheels ( and the list goes on)

Dealership may charge $100. Many have a minimum (even if you happen too accidentally find one that does it right). That minimum could be 1 hour, could be 1/2 hour, but it's likely not far from the cost of a DIY device.

Scenario 1 - dealer does the tire size recalibration. They look at the tire, hmm, a 33, and now you have two possibilities:
A. Dealer looks up the tire and sees the diameter posted is 32.8" and that's what they plug in. (gets you close if lucky)
B. Dealer measures tire as it sits on the truck and plugs it in (more correct)
And for each of those you have two possibilities -
tech uses his phone as GPS and checks accuracy
tech says "done, I plugged in what they told me, good enough"
I'd bet dinner on "I plugged in the number I found, I'm done" and the assistant drives it out and parks it and they call you it's done.

Scenario 2 - you purchase the software and cable needed to DIY. You now own the equipment. It costs only slightly more than the dealer's fee - sometimes about the same.
you plug in the numbers, take it for a drive and compare with GPS and it's off a bit, you go back, tweak the number, drive it again - perfect (well, within any reasonable figure anyway)

And then you drive it a year or two and decide now you want a tire change - any one of many reasons from a list of possible reasons - want to lift it and get bigger for climbing up the side of the Grand Canyon and crossing the Colorado River, or mudding with friends, or whatever.

With 1. you go back to a dealer, pay again, roll the dice as to is it A or B
With 2. you own the stuff, you don't pay a penny extra.

Or, 2 years later you decide you want a Toyota Prius instead and sell your JT - you can now sell your bypass cable, extension cable, and BT adapter for about half of what you paid and get a bunch of your money back.
With 1, the dealer has your money.

If you own the software and hardware, you can also do much much more - got an odd misfire, decided to add power locks or passive entry or change to LED lighting?
Well, you could pay a dealer to make those changes, or - you could already own everything you need to do it yourself.

I just can't see paying the big bucks and hoping you get a tech who actually plugs in correct numbers.
On the other hand - does anyone who takes their Jeep to a dealership to have the tire size change ever even both to LOOK to see if they did it right?
My bet is that half of those Jeeps done by a dealership are wrong if you compare the odometer and speedometer to fact.
Are they going to spend time? Or will they look at some chart, plug in a number and drive it out and collect your money and never bother to see if their number matches the reality.
I've looked up a fair number of tires and sometimes find that one site will say a tire is xx diameter and other have a different number..........

I guess I had to smile when I saw "done right" in the same sentence as the word "dealer".

If you will never do another thing to that Jeep, will never do anything else at all, don't care to ever reset any codes, read any codes, do any other diagnostics, will never change tires again and maybe not even keep it that long - the dealer may be worth it. Maybe - but to assume it will be done right, not so sure I'd go there as you can bet they won't do any more than go in, plug in a number, save it, and disconnect their equipment. It's up to you to test it and see if what they put in matches reality.

If I ever decide Jeep sucks, this is the last Jeep I'll ever own, sell 'em all, buy an Escape as a true off-road vehicle, I can at least recover some of my money selling the bypass cable and other stuff. You have an asset in those things, and it's an asset where the value keeps going up in the eyes of Jeep people (and even on Amazon - man, I'm glad I bought when I did.)



The problem comes in by size definition. The system stores it as a rolling circumference. The app or device translates that to a diameter.
So which diameter do you use? Is it a 33" tire? No, depending on the tire, brand, etc. it's likely a 32. 7 to 32.8 or similar while standing free.
But on the truck it's likely a 32.6
Took me two entries to get the odo and speedo to match GPS and reality. Nothing I looked up and plugged in was the exact number. I got it close, figured whether I needed to go higher or lower and changed the number a bit, tried it - spot-on.
Plus - if you change your mind in 2 years - you can go in and do it again for FREE. Dealer won't do it again for free. Sell the Jeep? Then sell the equipment and get some of your money back. Sell your Jeep? Can't go to a dealer and ask for money back because you sold your Jeep.

While being funny, I agree with everything you said. Yoko says my tires are 36.9. At the pressures I run daily, it's more like 36.8 (maybe 36.7). This is another reason why it's more beneficial to do it yourself. Dealership probably won't do all of that.

 

[tysongladiator]

I'm not sure I'd trust that one.
I was messing with displaying my steering angle in the dash display the other day while driving, and there's a good bit of movement, in both the steering wheel and the tires, before it reports a degree of angle change.
Assuming the JScan reads from the same source, I wouldn't rely on it to heavily for alignment setup.

Yea. There is a noticeable lag between the movement of the tires & steering wheel and what it displays on the dash. It would be interesting to see if that same lag is in the app as well.

 

[dmwphoto]

I can agree with those points @ShadowsPapa

 

[ShadowsPapa]

I'm not sure I'd trust that one.
I was messing with displaying my steering angle in the dash display the other day while driving, and there's a good bit of movement, in both the steering wheel and the tires, before it reports a degree of angle change.
Assuming the JScan reads from the same source, I wouldn't rely on it to heavily for alignment setup.

Nope - different.
What the off road stuff reports is the average tire angle calculated based on the steering wheel angle. It's not a direct read, it's a calculation.

It's a ratio as well, based on the steering gear ratio so xx degrees of steering wheel movement figured on a yy steering sector ratio gives zz tire angle - calculated average since there is Toe out on Turns to consider - right wheel angle will be different from left wheel angle so it's an average. Right may be 16 while left is 14.5 degrees and then it averages the two.
(JT is 13.3:1 ratio)
JSCAN directly reads the exact steering wheel angle directly.

 

[Jefe1018]

JSCAN if you feel comfortable, pay someone to make it their problem if you don’t.

Either way, nothing about this hobby has ever been cheap.

 

[Lunentucker]

Nope - different.
What the off road stuff reports is the average tire angle calculated based on the steering wheel angle. It's not a direct read, it's a calculation.

It's a ratio as well, based on the steering gear ratio so xx degrees of steering wheel movement figured on a yy steering sector ratio gives zz tire angle - calculated average since there is Toe out on Turns to consider - right wheel angle will be different from left wheel angle so it's an average. Right may be 16 while left is 14.5 degrees and then it averages the two.
(JT is 13.3:1 ratio)
JSCAN directly reads the exact steering wheel angle directly.

You ARE married, right?
Damned shame.

 

[Phi502]

Jscan can be done for less than $100.
Everything you need for Jscan:
Jscan app and license
Gateway interface cable https://amzn.to/3sNotzT
Bluetooth adapter https://amzn.to/3sSMLrV
Gateway Extension Cables https://amzn.to/3LecUbb (this is optional, but you will be glad you had it)

 

[Grump Fish]

Another vote for Jscan. I got the 3 VIN license so I could use it on both of our JTs. Changing tire size and TPMS settings was very easy and more cost effective than the other options.

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