Gear ratios and bad advice

374gatorgirl said:
Is driving in 2Hi recommended on the highway? Again, showing my lacking knowledge here.
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Yes, stay in 2H on paved and concrete surfaces.

For 4H and 4L you need a surface that allows the tire to slip (e. g. Snow, gravel, grass, dirt)
 
Rob5589 said:
There should be a tag on the diff cover/s that will have the ratio imprinted. Something like, 3.07, 3.73, etc is what you'll be looking for. The 3spd auto with 33's and 3.73 should actually be very usable. If it is performing poorly it is very likely you have 3.07.
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And without changing out the 3.07 to something more appropriate, there is really nothing that can be done to make speedometer correct?
 
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374gatorgirl said:
Oh I’m in a 3 speed automatic.
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2Hi, 4 Hi, and 4 Low refer to the transfer case, not the transmission.

2 Hi is with the lever as far forward as it goes. This is what you use for almost all of your on road driving.

Pull the lever back one notch and it engages 4wheel drive. Same ratio, but torque is applied to all four wheels instead of just 2. Used for gravel roads, snow, etc.

Pull it back 2 more notches (rolling at 1-2 mph while in neutral) and you’ll be in 4 wheel drive low range. Adds an extra gear reduction for extra torque and control.

Auto transmissions usually have one or two lower gears that you can select independently of the transfer case. These can be used when you need additional control off road, in stop and go traffic, etc
 
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Mr. Bills said:
Yes, the speedometer can be corrected two ways depending upon your particular transfer case. The first method is to change the plastic speedometer gear and the other is with an electronic device that alters the signal to the vehicle computer.

https://wranglertjforum.com/threads/speedometer-calibration.6098/
https://wranglertjforum.com/threads...ometer-after-changing-tire-sizes-or-gears.83/
https://www.google.com/search?q=how.....69i57j33.17643j0j7&sourceid=chrome&ie=UTF-8
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Thank you. The only issue is the charts don’t cover my combo. 33s and 3.07 gear ratio. So I’m unsure of which speedometer gear to get.
 
Mr. Bills said:
Yes, the speedometer can be corrected two ways depending upon your particular transfer case. The first method is to change the plastic speedometer gear and the other is with an electronic device that alters the signal to the vehicle computer.

https://wranglertjforum.com/threads/speedometer-calibration.6098/
https://wranglertjforum.com/threads...ometer-after-changing-tire-sizes-or-gears.83/
https://www.google.com/search?q=how.....69i57j33.17643j0j7&sourceid=chrome&ie=UTF-8
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The chart I attached link for is blank for the 33" tire/3.07 gear ratio, does that mean I would be unable to change the speedometer gear?
https://wranglertjforum.com/threads...ometer-after-changing-tire-sizes-or-gears.83/
 
Someone else may know if there is a "25" speedo gear, which is what the chart suggests would be appropriate for 33's and 3.07 gears, but unfortunately I do not.

If there isn't a "25," you could use the "26" gear specified for 3.07 gears and 32" tires and see how close that gets you (many tires listed as 33" in diameter are actually 32.8" or sometimes slightly less).
 
Mr. Bills said:
Someone else may know if there is a "25" speedo gear, which is what the chart suggests would be appropriate for 33's and 3.07 gears, but unfortunately I do not.

If there isn't a "25," you could use the "26" gear specified for 3.07 gears and 32" tires and see how close that gets you (many tires listed as 33" in diameter are actually 32.8" or sometimes slightly less).
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If you use a digital correction device, it doesn't matter what speedo gears are out there. They solve all the ratio tire size issues. We use them a fair bit with Atlas installs since the big tires and low gears require a gear that is too big to install while it is attached to the sender. You have to drop the gear in, tip it behind the drive gear and then stab the sender onto the shaft and pray that it stays snapped in. Easier and better to grab any smaller gear and then correct it digitally.
 
mrblaine said:
If you use a digital correction device, it doesn't matter what speedo gears are out there. They solve all the ratio tire size issues. We use them a fair bit with Atlas installs since the big tires and low gears require a gear that is too big to install while it is attached to the sender. You have to drop the gear in, tip it behind the drive gear and then stab the sender onto the shaft and pray that it stays snapped in. Easier and better to grab any smaller gear and then correct it digitally.
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Is this something that I can do myself? Do I install a smaller gear and then do this digital correction? I'm sorry if your explanation covered this and I'm jut not getting it.
 
mrblaine said:
If you use a digital correction device, it doesn't matter what speedo gears are out there. They solve all the ratio tire size issues. We use them a fair bit with Atlas installs since the big tires and low gears require a gear that is too big to install while it is attached to the sender. You have to drop the gear in, tip it behind the drive gear and then stab the sender onto the shaft and pray that it stays snapped in. Easier and better to grab any smaller gear and then correct it digitally.
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I would have suggested that because I have a Speedohealer electronic correction device myself and it couldn't be simpler to install and calibrate, but I assumed OP was looking for a lower cost option.

http://www.bluemonkeymotorsports.com/products_ht.html
 
Mr. Bills said:
Someone else may know if there is a "25" speedo gear, which is what the chart suggests would be appropriate for 33's and 3.07 gears, but unfortunately I do not.

If there isn't a "25," you could use the "26" gear specified for 3.07 gears and 32" tires and see how close that gets you (many tires listed as 33" in diameter are actually 32.8" or sometimes slightly less).
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So I read a few posts and people used the 26 for this combo and it worked. How do I determine whether I need a long or short shaft? I know its based on whether the speedometer is electronic or cable driven but how do I know the answer to this? Sorry for my general lack of knowledge here...
 
mrblaine said:
I despise the shit from a blue monkey.
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Care to explain. I have had no trouble with mine and the owner of Blue Monkey Motorsports provided me with great service not only when I purchased it but a year later when I re-geared and had forgotten how to set it.

I know there are other options but I have no familiarity with them.

Or were you joking?
 
374gatorgirl said:
So I read a few posts and people used the 26 for this combo and it worked. How do I determine whether I need a long or short shaft? I know its based on whether the speedometer is electronic or cable driven but how do I know the answer to this? Sorry for my general lack of knowledge here...
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I'm the wrong guy to ask. The last time I changed speedo gears was on a CJ with a Dana 300 transfer case. I used a Speedohealer electronic calibrator for my LJ because my '06 doesn't have speedo gears (linked above).
 
JMT said:
Great looking Jeep! Looks super clean. Congrats! Time now just to love Jeep life. With summer around, top down and doors off, nothing like it.

Good gas mileage will never be a TJ’s strong suit. It is what it is. Learn to punch penny’s and save for the next sheep mod, or gas!

To measure your true lift, look behind one of your front tires and find the big coil spring. You want to measure that spring. If there is a plastic spacer sitting on top of the spring, include that in the measurement. Don’t include the rubber coil spring isolator at the very top. Stock length is 12”, so anything above that is the amount of lift you have (e.g. 15” would mean you have 3” up front). Do the same in the rear, but stock is 8” and so anything over that is your lift in the rear.

Then report back. This will help determine what is the best tire size for your lift.

Then we can think about re-gearing for that tire size.

But for now just enjoy your new Jeep. There’s nothing else like it!
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So the front coil is 14.5” and the rear is 10.5” so both have a 2.5” lift, correct?
 
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