i want to run 35's but can the 3.73's handle it?
10-20-2009, 06:24 AM
#41
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I've got the RC 4" lift without control arms and RC quick disco's. I did not install the cam bolts as I plan on getting arms in a little bit, and didn't want to reweld. The ride is good, but I find the rear hops a little bit more, but after putting on the hardtop again for the winter, the extra weight helped alot. I did get one DW, and have since retorqued everything, and no problems. I haven't had a chance to get out wheeling yet, but I have noticed that just going over parking curbs, the Jeep was ALOT smoother, and with very little body roll. I've got an auto with 3.73's, Sahara unlimited. Looking back now, I think I should have waited and got a more complete kit from TF (long arm I think), but am still happy with the purchase, as I drive on pavement 85% of the time. I planned on 35's, but am now thinking 37's with new sleeves, shafts and gussets for the front, and a regear as well.
10-20-2009, 05:08 PM
#42
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The 'manufacturers' specs list it at 32", but what is the 'actual' tire height on your vehicle? (the majority of tires out there are considerably shorter on the vehicle than the specs tell us they are) Use the real height when comparing rpm's.
-for me personally, the mfg lists my tires at 33.27". Using the 'actual' measured height on my JK of 32", I am within 6rpm of what the chart shows.
Yes, they are under-geared/under-powered from the factory. (Specifically the auto's) It is open to debate, of course, but they are.
Another question would be - if 4.56 or 4.88 were factory options, and people actually knew about the current power and gearing situation to make an informed decision, how many would actually choose 3.21 or 3.73?
-for me personally, the mfg lists my tires at 33.27". Using the 'actual' measured height on my JK of 32", I am within 6rpm of what the chart shows.
Yes, they are under-geared/under-powered from the factory. (Specifically the auto's) It is open to debate, of course, but they are.
Another question would be - if 4.56 or 4.88 were factory options, and people actually knew about the current power and gearing situation to make an informed decision, how many would actually choose 3.21 or 3.73?
10-21-2009, 11:53 AM
#43
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I have 3:23 i think it is and run 35's lol no problem and it still spins the tires I dont ever reach 6th gear but i run all day up and down the freeway in 5th at 2200 rpm doing 70mph. 14.5-15.3 mpg
10-21-2009, 12:05 PM
#44
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I didn't read all the posts, but I will say this, based upon what I did read. Rough Country is an OK lift. Only OK. Save your money and get a better lift if you really are set on lifting and running 35s successfully. Why spend $20,000 on a jeep and put a decent lift on it when you could get better. For your purposes, look in to 2.5" lifts, from TeraFlex, Full Traction, Old Man Emu, Superlift. Don't hesitate to spend a little more and get a better lift that includes more components. I know that to keep the JK riding pleasantly, adjustable track bars are great and adjustable aftermarket control arms help out quite a bit. It's your Jeep, but still, plan plan plan.
Also, 3.73s would be fine with 35s. Very liveable. Not great...but, I have 3.21s and a 6 speed with my 35s. Yea, I can't crawl at all, and it's not ideal on the road, but it's fine until I can regear. Plus, you can select the gear you are in with the 6 speed so just downshift. Not bad.
Good luck on all your decisions and don't hold out just because you are afraid of gearing.
Also, 3.73s would be fine with 35s. Very liveable. Not great...but, I have 3.21s and a 6 speed with my 35s. Yea, I can't crawl at all, and it's not ideal on the road, but it's fine until I can regear. Plus, you can select the gear you are in with the 6 speed so just downshift. Not bad.
Good luck on all your decisions and don't hold out just because you are afraid of gearing.
10-21-2009, 04:52 PM
#45
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I recently regeared to 5.13s & ditched the 3.73. I am running 33s and definately love the ride...Even with running the stock 17" tires, it still felt kinda sluggish to me....Gears are the way to go, now when I upgrade to 35s it'll be all that much more fun to drive the JK around 
10-23-2009, 04:52 PM
#46
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I agree with planman on the 4" lift, you don't need that for 35s in fact it's possible to sit on top of 35s with no lift at all and some fender massaging. A 2.5" lift gets you there without fender modification and can be achieved without opening the can of worms that you get into with a 3" or more lift.
I'm not so much in line with planmans thoughts on the gears, although you'll probably want to get them at some point. The important thing is keeping your rpms up above 2,000 at highway cruise speeds. On the long highway flats you can probably squeeze that down to 1800 rpm and still retain good fuel mileage. Anything below that and speeds above 50mph you are not making good use of the engines power band while robbing your fuel mileage.
I'm not so much in line with planmans thoughts on the gears, although you'll probably want to get them at some point. The important thing is keeping your rpms up above 2,000 at highway cruise speeds. On the long highway flats you can probably squeeze that down to 1800 rpm and still retain good fuel mileage. Anything below that and speeds above 50mph you are not making good use of the engines power band while robbing your fuel mileage.
10-23-2009, 04:58 PM
#47
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10-23-2009, 05:09 PM
#48
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Should've edited my previous post...What I meant was that even running the stock 17" tires with the 3.73 gearing, the JK was a slug. I couldn't imagine what it would be like running that same gearing in an auto fitted w/35s......I am just glad I have since regeared to 5.13s...