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37" tires on dana 30

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Old 08-21-2013, 06:11 AM
  #21  
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Originally Posted by PhillyFire
I was just getting ready to ask the same question, as far at the 3.21 gears with 37's i've seen a couple folks here still running them, but i would imagine it would be pretty sluggish down low, auto trans or stick,, local shop quoted me $1200 for reinforcing and gusseting the front. seems a tad high, but it is past my skill level.. seen some nice rigs on here in the thread "37 club show and tell post" looks like it dates 3 years back,,
looking to do a 4 lift, 1.25 bod lift and a 20in 37 wheel tire package, very lite trail and beach use..
Mk krawlers is installing my axle truss, gussets and front control arm skids for 200-250. Probably end up being a lil more that was just s rough estimate....did in our area want an arm and a leg, they don't generally deal with rigs like ours. I was quoted 2 grand around here for what i listed above
Old 08-21-2013, 06:52 AM
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I have been running 38"s for a couple of years on a D30 with out any major issues and wheel as much as my sch allows...
Chromoly shafts
5:13
Gussets
Trussed
Old 08-21-2013, 07:34 AM
  #23  
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Originally Posted by JKinMA
Creeping up on one year with heavy Nitto 35" muds on my D30 with 2.5in lift, wheeled, dd, and thrashed (sometimes) with no complaints
That's great, did you do any mods to strengthen anything on the front end?

I stayed away from 35's because based on everything I could find it said that the axle's and drive shaft could likely fail...

So I have 33" Duratrac's with a 3" lift for now

Matthew
Old 08-21-2013, 07:40 AM
  #24  
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An unlocked axle, on a rig with an automatic tranny, that is not very heavy, and that doesn't get off roaded can handle 37s for a long time.

Other than maybe gussets, it is a waste of money to do upgrades on a D30 axle that will be run locked under a heavy JK.

You can find take-off Rubicon D44s for as low as $2k. If they have been regeared and gusseted already, you can find them for as low as $2.5k. If they have RCVs and upgraded ball joints, in addition to being regeared, they go for maybe $3k.

By the time you upgrade a D30 with cromoly shafts, a selectable locker, gussets and truss or sleeves, and regear it--particularly if you oay for labor--you will be into the D30 heavier $-wise than just buying a take-off Rubi D44. Plus, you will have smaller spline shafts and a smaller pinion shaft in the D30.

Now, if everyone takes my advice to skip putting money into D30s and buy take-off D44s, the used prices will go up and the value won't be as great. Until then, it makes no sense to significantly upgrade and lock a D30 and run 37s on an axle that will fail--not if, but when is the question.

Last edited by planman; 08-21-2013 at 07:51 AM.
Old 08-21-2013, 07:54 AM
  #25  
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Originally Posted by PhillyFire
I was just getting ready to ask the same question, as far at the 3.21 gears with 37's i've seen a couple folks here still running them, but i would imagine it would be pretty sluggish down low, auto trans or stick,, local shop quoted me $1200 for reinforcing and gusseting the front. seems a tad high, but it is past my skill level.. seen some nice rigs on here in the thread "37 club show and tell post" looks like it dates 3 years back,,
looking to do a 4 lift, 1.25 bod lift and a 20in 37 wheel tire package, very lite trail and beach use..
I've got a 2012 jk 2 door with manual transmission and 3:21 gears, when I went from 255/70/17's to 285/70/17 to Goodyear Duratrac's and now there is a small but noticeable difference mostly on the highway, 6th gear isn't used very often anymore

Plan on going to 4:10's pretty soon.

Matthew
Old 08-21-2013, 08:11 AM
  #26  
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Originally Posted by planman
An unlocked axle, on a rig with an automatic tranny, that is not very heavy, and that doesn't get off roaded can handle 37s for a long time.

Other than maybe gussets, it is a waste of money to do upgrades on a D30 axle that will be run locked under a heavy JK.

You can find take-off Rubicon D44s for as low as $2k. If they have been regeared and gusseted already, you can find them for as low as $2.5k. If they have RCVs and upgraded ball joints, in addition to being regeared, they go for maybe $3k.

By the time you upgrade a D30 with cromoly shafts, a selectable locker, gussets and truss or sleeves, and regear it--particularly if you oay for labor--you will be into the D30 heavier $-wise than just buying a take-off Rubi D44. Plus, you will have smaller spline shafts and a smaller pinion shaft in the D30.

Now, if everyone takes my advice to skip putting money into D30s and buy take-off D44s, the used prices will go up and the value won't be as great. Until then, it makes no sense to significantly upgrade and lock a D30 and run 37s on an axle that will fail--not if, but when is the question.
The one thing that concerns me about installing chromoly axle shafts and aftermarket ujoints is that by doing so wouldnt that make the ring and pinion the weak point which is more costly to replace than stock shafts and/or ujoints? I dont know much about this stuff so your input would be appreciated. Thanks
Old 08-21-2013, 10:21 AM
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Originally Posted by Monte417

The one thing that concerns me about installing chromoly axle shafts and aftermarket ujoints is that by doing so wouldnt that make the ring and pinion the weak point which is more costly to replace than stock shafts and/or ujoints? I dont know much about this stuff so your input would be appreciated. Thanks
No. Unless your axle housing is flexing, properly installed gears will not fail before front chromoly shafts and large u-joints.
Old 08-21-2013, 11:04 AM
  #28  
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Originally Posted by planman

No. Unless your axle housing is flexing, properly installed gears will not fail before front chromoly shafts and large u-joints.
Thank you for that
Old 08-21-2013, 12:18 PM
  #29  
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Originally Posted by kh202


<img src="https://www.jk-forum.com/forums/attachment.php?attachmentid=490076"/>
+ 1 for this post
Old 08-21-2013, 03:44 PM
  #30  
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Originally Posted by Jersey_Devil
I ran 37 km2 on my 2010 jku Sahara with factory 3.73s. NOT ONE PROBLEM. Didn't even have a problem hanging the 37 on my trail gate. Yes it was sluggish but it's a jeep, far as I'm concerned out was sluggish the day it rolled off the assembly line! Lol I'll post a pic in a lil bit, i don't have photos on my new phone
yeah anxious to see the pic,, hopefully the lil extra horse power in the 13's may compensate for the low gearing,,


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