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Old 01-31-2013, 01:21 PM   #31
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Ask Jerry bransford looking at your posts you seem to trust his opinion like most people on this forum do. He will tell you exactly as I did. You are under geared at 4.10 for 33 inch tires.

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Old 01-31-2013, 01:28 PM   #32
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Ask Jerry bransford looking at your posts you seem to trust his opinion like most people on this forum do. He will tell you exactly as I did. You are under geared at 4.10 for 33 inch tires.
I do agree, but I have driven several jeeps auto and standard that where geared 4.56s with 33's and on the highway at 65-70 turning 3,500rpms which is a little high, because it needed bigger tires for that low of gears.... Drove one of the same jeeps yesterday with new 35" km2s at 65-70mph it was at 2750 to 2850rpms which is a lot better...

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Old 01-31-2013, 01:31 PM   #33
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Trans is the 42rle not standard... lol??? Just my experience, but as you should know all jeeps are a little different lol....
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Old 01-31-2013, 01:50 PM   #34
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For the 4-speed automatic and 33" tires, 4.88 is the ratio you need. The 42RLE automatic's Overdrive ratio is a VERY steep .69 so you need to restore the RPMs with a lower axle ratio. 4.56 will make the engine lug, 4.88 is ideal for that combination.
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Old 01-31-2013, 01:50 PM   #35
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That's a quote from Jerry himself. Go read a book dude.
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Old 01-31-2013, 02:05 PM   #36
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Originally Posted by 99tj707 View Post
For the 4-speed automatic and 33" tires, 4.88 is the ratio you need.
x2. I'm running 42RLE/4.88s/33s. And I wish I could go even deeper, to 5.13s or 5.38s.
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Old 01-31-2013, 02:16 PM   #37
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Originally Posted by Shark_13

Lol beet me too it.....
*beat, not beet
*to, not too
__________________
Everybody dies, but not everyone lives.


2006 TJ 4l 6cyl 4'' Rancho 9000 XL
33''12.5 R15 Khumo MT's D44 Rear 4.56 gears
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Old 01-31-2013, 02:16 PM   #38
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And I go by the information that is current in the marketplace you can call up Randys Ring and Pinion or Yukon Gears and the will say they will all say same ratio for gearing I did...

It is a mathematical equation between the gearing in the transmission, over all circumference of the tirer and the axle gear ratio to get what is called crawl ratio with 4.10s and 33's you get a crawl ratio of what is in the link I posted here

4Lo.com :: Gear Ratio & Tire Size Chart
Awesome chart man, bookmarked that. Apparently since i run 31's and have 3.73 ratio, i have a better idea where to aim for rpm vs mpg. Im very green on mechanics but learning!
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Old 01-31-2013, 02:22 PM   #39
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Awesome chart man, bookmarked that. Apparently since i run 31's and have 3.73 ratio, I'm classed at (better gas mileage). Im very green on mechanics but learning!
That chart should really be relabeled. "Better gas mileage" should really be known as "under powered." Why would you add bigger tires and be fine with your vehicle running under factory spec?
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Old 01-31-2013, 02:27 PM   #40
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Seeing as how 4.10 is under geared for 33's I highly doubt that.
I drove 55 for a 100miles fueled up and did the math 6cyclinder 5speed got that number
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Old 01-31-2013, 02:27 PM   #41
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That chart should really be relabeled. "Better gas mileage" should really be known as "under powered." Why would you add bigger tires and be fine with your vehicle running under factory spec?
I didnt add my 31's, they were on the jeep new at the time of purchase. I dont want to get involved into an argument. I just thought that chart was helpful.
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Old 01-31-2013, 02:29 PM   #42
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I didnt add my 31's, they were on the jeep new at the time of purchase. I dont want to get involved into an argument. I just thought that chart was helpful.
I didn't mean to offend you in any way. Purely speaking on my view of that chart.
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Old 01-31-2013, 02:30 PM   #43
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I drove 55 for a 100miles fueled up and did the math 6cyclinder 5speed got that number
With 33's and 4.10's?
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Old 01-31-2013, 02:33 PM   #44
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I didn't mean to offend you in any way. Purely speaking on my view of that chart.
Thanks, i dont like to admit im green and the fact that some could sell me a horse when it really is a donkey if ya know what I mean lol im happy my mechanic is some i trust but trying to do more on my jeep on my own or atleast attempt to understand better. Its intimidating i guess.
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Old 01-31-2013, 02:38 PM   #45
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Thanks, i dont like to admit im green and the fact that some could sell me a horse when it really is a donkey if ya know what I mean lol im happy my mechanic is some i trust but trying to do more on my jeep on my own or atleast attempt to understand better. Its intimidating i guess.
A jeep is a great place to learn. And between the knowledge your mechanic and the people on this forum you will only become better at understanding things. To me working on my jeep is part of the fun.
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Old 01-31-2013, 08:29 PM   #46
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If you want to run 33's with the 4.0 you are going to want 4.56 with a stick or 4.88 with an auto. Period.


oh?

Guess my wrangler is just UNDRIVEABLE with my 3.73 gears and 33s
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Old 01-31-2013, 08:33 PM   #47
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my wrangler isn't a sports car. i don't treat it like one. If i need more power or go faster, i drop down a gear. if i still need more power, i go 4lo. Could the extra power and speed be nice sometimes? yea. sure. but i like not getting 12 mpg or spending the extra money on regearing. I still feel plenty capable power wise with 3.73
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Old 01-31-2013, 08:53 PM   #48
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my wrangler isn't a sports car. i don't treat it like one. If i need more power or go faster, i drop down a gear. if i still need more power, i go 4lo. Could the extra power and speed be nice sometimes? yea. sure. but i like not getting 12 mpg or spending the extra money on regearing. I still feel plenty capable power wise with 3.73
Guess i might as well park mine too, damn all this time i thought it was just fine... SILLY ME!!!

Only on the steepest hills do i need to down shift to fourth gear.
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Old 01-31-2013, 09:13 PM   #49
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Well I have a question my 98 to has a 4 banger and I have 33/12.5 on it.I'm the second owner and I don't know what gear is in it,how can I find out
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Old 01-31-2013, 09:19 PM   #50
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oh?

Guess my wrangler is just UNDRIVEABLE with my 3.73 gears and 33s
it'll roll down the road.

but if you're going to refute his statement, you have to factor in engine and transmission into your gear ratio/tire size rebuttal. because if you just assume a 1:1 like that chart, you're misleading less knowledgeable people and lying to yourself.
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Old 01-31-2013, 09:23 PM   #51
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Clint98:

What type of rear differential do you have? Has it been changed or did you change? If not do a search on decoding ur VIN using a site like this: Free VIN number decoder for any cars thats how i found out i had a dana 44 in the back, gear ratio 3.73

Hope that helps, if not there are other free decoders might help u out...
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Old 01-31-2013, 10:12 PM   #52
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Quote:
Originally Posted by RevCo666
Clint98:

What type of rear differential do you have? Has it been changed or did you change? If not do a search on decoding ur VIN using a site like this: Free VIN number decoder for any cars thats how i found out i had a dana 44 in the back, gear ratio 3.73

Hope that helps, if not there are other free decoders might help u out...
He took the words out of my mouth. If that doesn't help you can look at the stamp on the rear axle
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Old 01-31-2013, 11:00 PM   #53
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it'll roll down the road.

but if you're going to refute his statement, you have to factor in engine and transmission into your gear ratio/tire size rebuttal. because if you just assume a 1:1 like that chart, you're misleading less knowledgeable people and lying to yourself.
yea yea, i know, you are right. ive read your posts on the very topic. I do know its wrong and you are more knowledgeable on prob most everything.
It was more just a vent that although some people would prefer 4.88 gearing with 33s, I would NEVER throw that high of gearing in there for that size. I have more power than I use on the trail and i would prefer not to be at 3000+ rpms on the freeway. I wouldn't mind having the 4.10s but thats as high as I would go with 33s and a 5 speed. If i ever go to 35s, ill prob go as high as 4.56
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Old 01-31-2013, 11:55 PM   #54
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So just a thought since we are talking about highway driving here. I love my TJ, but she is about as aerodynamic as a brick and I know she isn't a sports car. You want better highway drivability and efficiency, you have to overcome the laws of physics.

Your best chance is as low to the ground as possible, and those big fat mud tires sticking out the sides aren't going to help you any. And wranglers just are not intended to be setup this way.

You either keep it close to stock for road use, or jack em high for off road fun. Kind of difficult finding a happy medium between the 2.

So my opinion, somebody mentioned a beater civic for daily driver earlier. If you can afford the insurance, it's not a bad idea. Decent mileage, a little passing power on the highway. Sure they aren't the fastest but it's a daily driver and you can get one cheap. Then set your wrangler up as a play toy.

but please please please, don't put one of those fart can exhausts on the civic. I can't stand listening to those things.
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Old 02-01-2013, 05:20 AM   #55
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If you are fine with driving your jeeps under powered that is your choice. Albeit I don't agree with you. I was simply stating what needs to be done to the gears to achieve factory drive ability. If you are fine with driving your car underpowered and far from its potential be my guest.
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Old 02-01-2013, 09:20 AM   #56
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With 33's and 4.10's?
Yes and the correct spedo gear 6cyclinder 33x10.5 bfg km2s just for a little more information
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Old 02-01-2013, 09:32 AM   #57
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My Jeep is a 4.0 Auto with 3.07 gears and 31's. It rolls just fine for my liking. I guess I am just used to it. Then again it is not a DD and just a fun vehicle or a backup if one of the others is out.

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