Wrangler JK Upgrade Choice: Axle Gear Ratio or Transfrer case?


My current rig has DANA30 front, DANA44 rear, 3.73 ratio, limited rear slip differential, stock 30 inch tire. Nothing exciting and pure stock performance.

I am planning to upgrade it to fit in 35 inch tire. To me, all upgrade should
start from a healthy internal meachnism.

Therefore, I think before resizing the tire, a upgrade in the gear ratio
is needed so that the effective gear ratio will be near stock for on street
driving and really low for good trail performance.

Now I am facing two choices, upgrade axle gear ratio or upgrade transfer case.
My research so far so showed the pro/cons on each choice as

Axle Gear Ratio Upgrade:
Pro: Parts price is affordable, 400 dollars can get both front and rear
pinion/ring pairs.

A lot of ratios can be selected ranging from 4.1 to 5.38.

Can be done with locker upgrade at the same time.

Con:
Expensive labor.

DIY is hard, not only because you have to deal with a lot of stuff
before reaching the pinion and ring part, but also the adjustment of
backlash and preload is quite tricky and time consuming.

have to do it on both front and rear axle

When upgrading the gear ratio, if we do not upgrade axle
(from DANA30 to DAN44 or from DANA44 to DAN60)
it will make the axle weaker.
This is because lower gear ratio require smaller
pinion size or larger number of ring gear teeth, making
contact area between pinion teeth and ring teeth smaller than
stock size.


Transfre Case Upgrade:
Pro: Just need to change one part (transfer case) then two (two axles)

Atlas-4speed unit provide a wide choices of gear ratio. Compared
to it, stock transfer case provide only two choices, the one for street
use is too low and one for trail is too high.

keep the stock axle strenght without weakening it

Cons: Expensive Part, expensive labor

Do not know if it is suitable for DIY, since it seems like a
really big change and you have to at least cut center console
to let the new stick of the transfer case to through


All above is my current research result and there maybe some erros.
corrections/comments/suggestions?

所有跟帖: 

wow.你怎么知道我来了。 -杀雨- 给 杀雨 发送悄悄话 杀雨 的博客首页 (1012 bytes) () 10/05/2009 postreply 13:08:58

Glad to see you again -wolfmanii- 给 wolfmanii 发送悄悄话 wolfmanii 的博客首页 (1860 bytes) () 10/05/2009 postreply 20:36:17

回复:wow.你怎么知道我来了。 -wolfmanii- 给 wolfmanii 发送悄悄话 wolfmanii 的博客首页 (1860 bytes) () 10/05/2009 postreply 20:36:39

BTW, what's your JK upgrade status -wolfmanii- 给 wolfmanii 发送悄悄话 wolfmanii 的博客首页 (208 bytes) () 10/05/2009 postreply 20:47:09

一点意见。 -杀雨- 给 杀雨 发送悄悄话 杀雨 的博客首页 (1834 bytes) () 10/05/2009 postreply 22:59:09

A question about transfer case -wolfmanii- 给 wolfmanii 发送悄悄话 wolfmanii 的博客首页 (383 bytes) () 10/06/2009 postreply 06:37:46

分动箱的任务是通过前传动轴传送扭力到前桥。 -杀雨- 给 杀雨 发送悄悄话 杀雨 的博客首页 (156 bytes) () 10/06/2009 postreply 07:19:04

Just for discussion -wolfmanii- 给 wolfmanii 发送悄悄话 wolfmanii 的博客首页 (192 bytes) () 10/06/2009 postreply 07:41:11

回复:Just for discussion -杀雨- 给 杀雨 发送悄悄话 杀雨 的博客首页 (260 bytes) () 10/06/2009 postreply 18:35:19

Agree -wolfmanii- 给 wolfmanii 发送悄悄话 wolfmanii 的博客首页 (98 bytes) () 10/06/2009 postreply 20:58:54

What is the Best all around Gear Ratio for my rig? -wolfmanii- 给 wolfmanii 发送悄悄话 wolfmanii 的博客首页 (408 bytes) () 10/06/2009 postreply 06:39:13

4.88,你会喜欢很长一段时间。 -杀雨- 给 杀雨 发送悄悄话 杀雨 的博客首页 (0 bytes) () 10/06/2009 postreply 07:20:38

OK, 4.88 upgrade, then about the locker -wolfmanii- 给 wolfmanii 发送悄悄话 wolfmanii 的博客首页 (1086 bytes) () 10/06/2009 postreply 07:59:02

回复:OK, 4.88 upgrade, then about the locker -杀雨- 给 杀雨 发送悄悄话 杀雨 的博客首页 (442 bytes) () 10/06/2009 postreply 18:50:53

Mechanical vs Air Locker -wolfmanii- 给 wolfmanii 发送悄悄话 wolfmanii 的博客首页 (456 bytes) () 10/06/2009 postreply 20:57:27

ARB是想锁就锁,机械锁是一直都锁着的,踩离合器的时候才断开。 -杀雨- 给 杀雨 发送悄悄话 杀雨 的博客首页 (118 bytes) () 10/07/2009 postreply 13:18:15

From what I read, ox locker is like ARB -wolfmanii- 给 wolfmanii 发送悄悄话 wolfmanii 的博客首页 (172 bytes) () 10/07/2009 postreply 18:21:13

BTW欢迎到加国和我们一起越野。 -杀雨- 给 杀雨 发送悄悄话 杀雨 的博客首页 (93 bytes) () 10/05/2009 postreply 23:03:06

I would love to join :) -wolfmanii- 给 wolfmanii 发送悄悄话 wolfmanii 的博客首页 (313 bytes) () 10/06/2009 postreply 06:41:51

还 是 先 来 我 这 里 吧 , 我 在 北 卡 -苏武牧狼- 给 苏武牧狼 发送悄悄话 苏武牧狼 的博客首页 (45 bytes) () 10/06/2009 postreply 19:41:18

Yes, you are much closer -wolfmanii- 给 wolfmanii 发送悄悄话 wolfmanii 的博客首页 (63 bytes) () 10/06/2009 postreply 21:09:37

我自己越野玩 -苏武牧狼- 给 苏武牧狼 发送悄悄话 苏武牧狼 的博客首页 (64 bytes) () 10/06/2009 postreply 21:39:21

回复:Wrangler JK Upgrade Choice: Axle Gear Ratio or Transfrer case -jeepercreeper- 给 jeepercreeper 发送悄悄话 (51 bytes) () 10/06/2009 postreply 20:57:07

目前居住在卡城,calgary. -杀雨- 给 杀雨 发送悄悄话 杀雨 的博客首页 (0 bytes) () 10/07/2009 postreply 13:24:58

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