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Help Dialing In Rubicon with Mopar Lift and 37s

caraddictionisreal

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So I have had the fortune of taking a few 200 mile highway trips in my Rubicon with 2" Mopar lift, Fox steering Stabilizer, and 37x12.5r17 Ridge Grapplers. She is not a German luxury car for sure. I wanted to get some feedback from others with similar setups on ways to make this thing a little more stable at speed (and yes, I know its still a Jeep as this is my fourth Wrangler...TJ, JKR, JKUR, JTR). I have two issues I'm trying to resolve.

1. Steering and Alignment- Other than the Mopar lift and Fox Steering Stabilizer (supposedly they installed a track bar upgrade but it looks stock to me), nothing else has been changed. I am on a waiting list for parts for the steering box TSB, which I hope will nullify the dead spot at center which makes the truck dance when you pass a big rig. The tires currently look to have a little bit of negative camber in the front. My question is...What else do I need to do to neutralize the steering and make sure the axles, wheels/tires are mechanically in line to work properly? Or should I just get the steering box changed and an alignment and call it a day?

2. Shift Points- I added the Tazer Mini to correct for the increased tire size, hoping it would also somehow adjust the shift points. Accelerating, I sometimes notice it hangs in a gear way too long. At Interstate speed, it also doesn't like going into 7 or 8, so its often running at 2.5 to 3k RPM for long periods. Should I make adjustments to the Tazer settings or is there some other reprogram available. Not interested in doing gears or anything crazy expensive, but I'd like to get it dialed in so its livable (and safe) to drive daily.

Thanks in advance for the Feedback.

Jason
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Nespeezy

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So I have had the fortune of taking a few 200 mile highway trips in my Rubicon with 2" Mopar lift, Fox steering Stabilizer, and 37x12.5r17 Ridge Grapplers. She is not a German luxury car for sure. I wanted to get some feedback from others with similar setups on ways to make this thing a little more stable at speed (and yes, I know its still a Jeep as this is my fourth Wrangler...TJ, JKR, JKUR, JTR). I have two issues I'm trying to resolve.

1. Steering and Alignment- Other than the Mopar lift and Fox Steering Stabilizer (supposedly they installed a track bar upgrade but it looks stock to me), nothing else has been changed. I am on a waiting list for parts for the steering box TSB, which I hope will nullify the dead spot at center which makes the truck dance when you pass a big rig. The tires currently look to have a little bit of negative camber in the front. My question is...What else do I need to do to neutralize the steering and make sure the axles, wheels/tires are mechanically in line to work properly? Or should I just get the steering box changed and an alignment and call it a day?

2. Shift Points- I added the Tazer Mini to correct for the increased tire size, hoping it would also somehow adjust the shift points. Accelerating, I sometimes notice it hangs in a gear way too long. At Interstate speed, it also doesn't like going into 7 or 8, so its often running at 2.5 to 3k RPM for long periods. Should I make adjustments to the Tazer settings or is there some other reprogram available. Not interested in doing gears or anything crazy expensive, but I'd like to get it dialed in so its livable (and safe) to drive daily.

Thanks in advance for the Feedback.

Jason
 

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As far as #2 goes, did you make sure the tire size was measured and entered exactly as they sit mounted on your JT? When I got 35s I just put in “35” height and it shifted wonky. My 35s actually measured around 33.8 mounted with 32 PSI. It shifts great now.
 

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So I have had the fortune of taking a few 200 mile highway trips in my Rubicon with 2" Mopar lift, Fox steering Stabilizer, and 37x12.5r17 Ridge Grapplers. She is not a German luxury car for sure. I wanted to get some feedback from others with similar setups on ways to make this thing a little more stable at speed (and yes, I know its still a Jeep as this is my fourth Wrangler...TJ, JKR, JKUR, JTR). I have two issues I'm trying to resolve.

1. Steering and Alignment- Other than the Mopar lift and Fox Steering Stabilizer (supposedly they installed a track bar upgrade but it looks stock to me), nothing else has been changed. I am on a waiting list for parts for the steering box TSB, which I hope will nullify the dead spot at center which makes the truck dance when you pass a big rig. The tires currently look to have a little bit of negative camber in the front. My question is...What else do I need to do to neutralize the steering and make sure the axles, wheels/tires are mechanically in line to work properly? Or should I just get the steering box changed and an alignment and call it a day?

2. Shift Points- I added the Tazer Mini to correct for the increased tire size, hoping it would also somehow adjust the shift points. Accelerating, I sometimes notice it hangs in a gear way too long. At Interstate speed, it also doesn't like going into 7 or 8, so its often running at 2.5 to 3k RPM for long periods. Should I make adjustments to the Tazer settings or is there some other reprogram available. Not interested in doing gears or anything crazy expensive, but I'd like to get it dialed in so its livable (and safe) to drive daily.

Thanks in advance for the Feedback.

Jason
Jason
I have been trying to get mine right for months. Don’t have an off-road shop however I have 3.5 with all 8 arms. I have the synergy steering bracket and I too am on waiting list for new steering box. My steering sucks too. I will tell u I am getting closer. Adding caster to front helped. Getting close to 6 degrees and getting toe as close to zero will help a bit. Let me know. This should be achievable with the 2 inch lift.
 
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caraddictionisreal

caraddictionisreal

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As far as #2 goes, did you make sure the tire size was measured and entered exactly as they sit mounted on your JT? When I got 35s I just put in “35” height and it shifted wonky. My 35s actually measured around 33.8 mounted with 32 PSI. It shifts great now.
I did. I should probably check to make sure the measurement saved, but these 37s are really 35.8s.
 

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So I have had the fortune of taking a few 200 mile highway trips in my Rubicon with 2" Mopar lift, Fox steering Stabilizer, and 37x12.5r17 Ridge Grapplers. She is not a German luxury car for sure. I wanted to get some feedback from others with similar setups on ways to make this thing a little more stable at speed (and yes, I know its still a Jeep as this is my fourth Wrangler...TJ, JKR, JKUR, JTR). I have two issues I'm trying to resolve.

1. Steering and Alignment- Other than the Mopar lift and Fox Steering Stabilizer (supposedly they installed a track bar upgrade but it looks stock to me), nothing else has been changed. I am on a waiting list for parts for the steering box TSB, which I hope will nullify the dead spot at center which makes the truck dance when you pass a big rig. The tires currently look to have a little bit of negative camber in the front. My question is...What else do I need to do to neutralize the steering and make sure the axles, wheels/tires are mechanically in line to work properly? Or should I just get the steering box changed and an alignment and call it a day?

2. Shift Points- I added the Tazer Mini to correct for the increased tire size, hoping it would also somehow adjust the shift points. Accelerating, I sometimes notice it hangs in a gear way too long. At Interstate speed, it also doesn't like going into 7 or 8, so its often running at 2.5 to 3k RPM for long periods. Should I make adjustments to the Tazer settings or is there some other reprogram available. Not interested in doing gears or anything crazy expensive, but I'd like to get it dialed in so its livable (and safe) to drive daily.

Thanks in advance for the Feedback.

Jason
There is a youtube video somewhere about how to adjust the power steering box that can help with the dead spot. Supposedly works well with the TSB, but i havent personally tried it.

shift points, as mentioned, measure wheels exactly. I will say, that IMO, re-gearing should have been a part of budgeting for 37's. The truck is never going to drive as well as it should with 37's and 4.10's. Its fine around town as a pavement princess, but once you get into even the hills around NC/TN/VA etc you'll struggle. If you go out west, forget about it. If you are adamant on not doing a regear, then you'll just have to get used to being in lower gears and rev'ing higher most of the time. if you have a true 37, then your effective gearing is taller than a stock jeep with 3.73 and smaller passenger car tires. its just too much gearing and too much rotational mass.
 
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caraddictionisreal

caraddictionisreal

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There is a youtube video somewhere about how to adjust the power steering box that can help with the dead spot. Supposedly works well with the TSB, but i havent personally tried it.

shift points, as mentioned, measure wheels exactly. I will say, that IMO, re-gearing should have been a part of budgeting for 37's. The truck is never going to drive as well as it should with 37's and 4.10's. Its fine around town as a pavement princess, but once you get into even the hills around NC/TN/VA etc you'll struggle. If you go out west, forget about it. If you are adamant on not doing a regear, then you'll just have to get used to being in lower gears and rev'ing higher most of the time. if you have a true 37, then your effective gearing is taller than a stock jeep with 3.73 and smaller passenger car tires. its just too much gearing and too much rotational mass.
Thanks for the feedback. Mine is mostly a daily driver/mall crawler and I have a bad habit of trading out cars frequently, so not sure I want to commit the resources to swapping gears at this point. I have played with the tire size a little with the Tazer Mini and it seems to shift a little better at highway speeds, though it still occasionally seems to get a case of the stupids and hang in a lower gear for too long.

As for the steering, I am #3 on the local stores list for parts, but they claim to not have received parts for over a month. I plan on doing the TSB and an alignment first, then seeing if there is still a gap.
 

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Sounds like you need to regear to 4.88's. Since it's mainly highway.
 

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You will never get the shifting right or be able to use 7th and 8th as intended as long as you stay at 4.10's. You will need to go to 4.88's or even 5.13's to get into 7th and 8th. About the best you are going to be able to do is use the Tazer to get your speedometer correct by adjusting your tire size.
I have a 3" Rock Krawler no limits lift kit with adjustable upper and lower control arms with 37" tires and mine tracks and drives great on the highway, so first you will need to get the steering fixed with the TSB, which you are. Then start dealing with issues if there are any at that time. As stated earlier try and get your castor to 6 degrees. Since your lift does not have any adjustable control arms you could do drop brackets to correct your castor. They work pretty well and it sounds like you do not do any hard offroading so they should work fine for your application.
Someone can correct me if I am wrong here but does the mopar kit come with a longer track bar to keep the front axle centered? If that is what they installed then your axle should be centered. Have you measured from side to side to verify that the axle is centered? Also check the rear for center.
Only other thing that can help or hurt is tire pressure. To high and it will drive really stiff on the road, you feel everything you are going over. To low and the tire will roll and track every track in the highway. Do a chalk test across your tread and adjust your tire pressure until almost all of the line is rubbed off when rolled, leaving just barely some chalk on the very edges of the tire. I run mine at 35 psi. on the highways and that feels pretty good. That does make mine run on the centers a bit more but I was told that Milestar Patagonias need that to use the center for wear and quietness of the tire.
 

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You will never get the shifting right or be able to use 7th and 8th as intended as long as you stay at 4.10's. You will need to go to 4.88's or even 5.13's to get into 7th and 8th. About the best you are going to be able to do is use the Tazer to get your speedometer correct by adjusting your tire size.
I have a 3" Rock Krawler no limits lift kit with adjustable upper and lower control arms with 37" tires and mine tracks and drives great on the highway, so first you will need to get the steering fixed with the TSB, which you are. Then start dealing with issues if there are any at that time. As stated earlier try and get your castor to 6 degrees. Since your lift does not have any adjustable control arms you could do drop brackets to correct your castor. They work pretty well and it sounds like you do not do any hard offroading so they should work fine for your application.
Someone can correct me if I am wrong here but does the mopar kit come with a longer track bar to keep the front axle centered? If that is what they installed then your axle should be centered. Have you measured from side to side to verify that the axle is centered? Also check the rear for center.
Only other thing that can help or hurt is tire pressure. To high and it will drive really stiff on the road, you feel everything you are going over. To low and the tire will roll and track every track in the highway. Do a chalk test across your tread and adjust your tire pressure until almost all of the line is rubbed off when rolled, leaving just barely some chalk on the very edges of the tire. I run mine at 35 psi. on the highways and that feels pretty good. That does make mine run on the centers a bit more but I was told that Milestar Patagonias need that to use the center for wear and quietness of the tire.
Mopar lift uses stock track bar. You have to go aftermarket to recenter the axle.
 

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You will never get the shifting right or be able to use 7th and 8th as intended as long as you stay at 4.10's. You will need to go to 4.88's or even 5.13's to get into 7th and 8th. About the best you are going to be able to do is use the Tazer to get your speedometer correct by adjusting your tire size.
I have a 3" Rock Krawler no limits lift kit with adjustable upper and lower control arms with 37" tires and mine tracks and drives great on the highway, so first you will need to get the steering fixed with the TSB, which you are. Then start dealing with issues if there are any at that time. As stated earlier try and get your castor to 6 degrees. Since your lift does not have any adjustable control arms you could do drop brackets to correct your castor. They work pretty well and it sounds like you do not do any hard offroading so they should work fine for your application.
Someone can correct me if I am wrong here but does the mopar kit come with a longer track bar to keep the front axle centered? If that is what they installed then your axle should be centered. Have you measured from side to side to verify that the axle is centered? Also check the rear for center.
Only other thing that can help or hurt is tire pressure. To high and it will drive really stiff on the road, you feel everything you are going over. To low and the tire will roll and track every track in the highway. Do a chalk test across your tread and adjust your tire pressure until almost all of the line is rubbed off when rolled, leaving just barely some chalk on the very edges of the tire. I run mine at 35 psi. on the highways and that feels pretty good. That does make mine run on the centers a bit more but I was told that Milestar Patagonias need that to use the center for wear and quietness of the tire.
You are right on point. He should not have any issues with a 2 inch lift. TSB then alignment. 5.5 to 6 degrees of caster make sure your thrust angle is on point as well. I have a Clayton 3.5 inch lift all 8 arms as well and just replaced both drive shafts. Just waiting for gear box to come in for the TSB.
 

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This thread sure turned into a "you need to regear or else the world will end" thread really quick...
OP- Make sure you are not using 37 as your diameter with the Tazer. Measure the tire radius from the ground to the center of the hub, then double it to find out your effective tire diameter.
 

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This thread sure turned into a "you need to regear or else the world will end" thread really quick...
OP- Make sure you are not using 37 as your diameter with the Tazer. Measure the tire radius from the ground to the center of the hub, then double it to find out your effective tire diameter.
I would think this would not be a good way to do it because you are effectively doubling the “squish” that exists at the bottom that does not exist at the top. If you have 1” of squish at the bottom you would effectively be reducing tire height by 2” instead of just 1”. This would have the same ill effect as entering in the height with no weight on the tire, just in the opposite direction. If you are going through the exercise of measuring, just measure from the top of the tire to the ground (place a level on the top of the tire and measure to the ground). Am I thinking incorrectly on this?
 

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The "squish" doesn't make your tire smaller in circumference, it is flattening out which does make the height shorter. Measuring the mounted height is also wrong. Your speedometer needs tire circumference, aka, the length of the tread at operating pressure. This is how far your vehicle travels for every axle rotation. Tire circumference is a large number and wouldn't make sense to most because that's not how you buy tires. Hence any of the programmers just ask for tire diameter.

You'll need a helper to spot you but using chalk, mark your tire and ground at the same spot, draw a line from the sidewall down to the ground. This is your starting point. If it was an analog clock, it would look like it was 6:30.

Have someone drive the Jeep and watch for the chalk mark to get back down to the bottom again, mark the ground here as well.

Measure between those 2 lines on the ground. This is your circumference. To get a number to enter in your programmer you need to get back to diameter. C=pi*D, circumference = 3.14 * diameter. Divide your measured number by 3.14 and you'll have diameter out to several decimal places.

Let's say you bought 37's, the manufacturer states they are really 36.2" at mounted pressure. Do the above chalk line measuring.

Point 1 to point 2 on the ground measures 113.5", again, this is how far you roll for one axle rotation, your computer only knows how fast the axle rotates, it has no idea what size tire you have.

Take 113.5" and divide by 3.14, this says your true tire size is 36.15" tall. This would be what you enter into your programmer.

This will get you very close on your speedometer and odometer correction. Taking into account that they are very rarely perfect from the factory as well.
 

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I have a Rubicon with 2.5" Clayton overland lift and 37's. Same tires you have. Got mine back from tsb steering update 2 days ago. It is a completely different truck. Steering is normal now. Go down the interstate at 70mph with little or no steering update. It made me so happy.
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