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Unread 10-23-2013, 09:11 AM   #1
atlshaun
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Scrambler re-gearing question

FINALLY found a Scrambler and it's on the way from Arizona as we speak.

It has the stock AMC 20 Axle and I am going to immediately put a 2.5" BDS lift and a 1" body lift with 33" tires.

I want to have it regeared, so here is my situation:

This Jeep will be primarily used as my hunting vehicle. I am not trying to Rock crawl or anything remotely close, although it must be capable of driving through muddy roads, hills, etc... in the woods.

Secondly, I hunt about 100 miles away, 80 of which will be on the interstate.

I have researched gearing and conventional wisdom, and the charts, would advise me to go with ~4.11 gears. However, my simpleton math tells me that 3.73 gears should provide roughly 91% of the torque of the 4.11 gears in 1st gear, and 3.91 would provide ~95%, so I shouldn't lose "that much" torque in the lower gears but I should gain speed and gas mileage on the highway.

What would you recommend in this situation?

3.73
3.91
4.11

Thx in advance!

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Unread 10-23-2013, 09:19 AM   #2
jp360cj
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What engine/transmission does it have?
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77 CJ-7- AMC 360, Edelbrock cam, MC2100, Fenderwells, CJ T18/D20, Chevy D44/EB 9" rear, Trutrac f/r, 4.11, SOA, 1.25 lift shackles, 35x12.50 BFG KM2s, Shackle Reversal
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Unread 10-23-2013, 09:22 AM   #3
atlshaun
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258
t-5
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Unread 10-23-2013, 11:33 AM   #4
arkiemurph
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Tire size makes a big difference. Any idea what tires you're gonna be running? That T-5 will help you a lot on the highway. Just don't abuse it. It won't take abuse.

Murph
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Unread 10-23-2013, 11:45 AM   #5
seabass1858
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if you have the t-5 i would be partial to 4.56s. I put 4.10s and 32x10.50s on my liberty and love that combo. I would think with 33x12.50s and 4.56 would be perfict all around and keep stress off the t-5. detroit trutracs are also a great streatable locker and again have them in the liberty with 40k miles and flawless operation. I live in ft benning and have a set of aluminum 15x10 pacer wheels if you want. take a look at my build thread if your interested. Im always up in atlanta because my sons neurosurgeons are up there. Let me know if interested im just waiting for my original rims to come in.
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Unread 10-23-2013, 01:14 PM   #6
atlshaun
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Quote:
Originally Posted by arkiemurph View Post
Tire size makes a big difference. Any idea what tires you're gonna be running? That T-5 will help you a lot on the highway. Just don't abuse it. It won't take abuse.

Murph
33x12.5x15
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Unread 10-23-2013, 02:21 PM   #7
gwolff
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I have 4.10's with a t-19 in mine w/33's and in 4th (1-1) it's perfect. With OD I think I would also go with 4.56's.
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Unread 10-24-2013, 12:24 PM   #8
wm69
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T5 and 33's there's a good chance you'll eat the tranny.

Spankrjs over on the Scrambler board has gone through 3 T5's in the last year running 33's. They just aren't meant for anything more than stock.

http://www.cj-8.com/forum/showthread...E-AGAIN/page75
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85 CJ7 258, A/C, T176, MC2100, Team Rush, Warn XD8000i, superwinch hubs, 3in lift 31" BFG AT/KO
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Unread 10-24-2013, 01:23 PM   #9
foggybottombob
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There are two versions of T5. One has a 0.76 5th gear and the other has a 0.86 ratio 5th. If you have the 0.76 5th I would recommend 4.30/4.27 if you can get it. If you have the 0.86 ratio 5th gear I would recommend 4.09/4.10. I had the first one with 33" tires and 4.30 gears for years and crawled it hard. It also ran 70 mph on the interstate. Best mileage I ever got with the 33's, 4.30s and the AMC 258 with 4.0 head and Carter carb was 17.
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Unread 10-25-2013, 01:44 PM   #10
80cj
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3.91's are not available for the AMC 20 axle. If you have a T-5, I would go to 4.10's no hesitation. It will still cruise nicely on the highway with 33's. As foggy says, 4.27/4.30 would be great but those ratios are not available for the AMC 20.
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Unread 10-25-2013, 04:40 PM   #11
gwolff
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As mentioned, 4.56's.
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