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JL Dana 30 & Dana 35 - how strong are they?

Therby

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So you are running 35's on a JLU sport with 4.56 gears and 80MPH at 2k rpm. That sounds great. Auto or Manual transmission? I didn't see the start of this part of the thread. Doing what most are and re-gearing, lockers and 35" tires. I have a 6 speed Manual and having a hard time between 4.10 and 4.56. The charts all say to go with 4.10 but most people say they are getting better low end performance witht eh 456.
I have a manual transmission, 2dr on 315/70r17 and went with 4.56 dana gears.

id recommend this set up, makes it much nicer to drive with 35s and is great on the trail
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Jeep’n Jay

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So you are running 35's on a JLU sport with 4.56 gears and 80MPH at 2k rpm. That sounds great. Auto or Manual transmission? I didn't see the start of this part of the thread. Doing what most are and re-gearing, lockers and 35" tires. I have a 6 speed Manual and having a hard time between 4.10 and 4.56. The charts all say to go with 4.10 but most people say they are getting better low end performance witht eh 456.
Mine is automatic..... close to 2100 rpm at 80, 75 mph I can cruise at 1900 rpm
 

mgroeger

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Posted yesterday trying to identify my axles, looks like I've got the M186 front and M200 rear. My local 4x4 shop suggested not to do a regear on the dana 35 and definitely not on the dana 30, instead just save up for new axles all together, purely because they aren't strong enough. I'm not sure if he's basing that decision on the old JK axles.

Looking to go 4.56 or 4.88 with 35's. Anyone have any experience regearing on the 30 & 35?
We were in the same boat before we decided to just swap out the axles and put D44s in it.

In a nut shell whoever that guy is who told you that is on the right track.
There was another guy on the forum who actually called Dana/Spycer and told them he wanted to run 35s on the D30/35 axles on his Sport. They said if you are just going to mall crawl and do LITE trails you should be fine but beyond that they said you will be running a risk on them.
The solution would be to do an axle disconnect delete in the front and go with chromoly axle shafts both front and rear. But as noted by others your U joints would then become the weak link. Switching to RCV axles up front would really put you in a good spot. Doing that, personally, I'd feel good about gears and even lockers on a beefed up D30/D35 axle set.
A re-gear is going to run you around $2k to have a pro do it or around $1k to do it yourself, approximately. You can pick up a set of factory D44s WITH lockers and 4.10 gears and a two year warranty from a dealer for about $4800. Then tack on another $1800 or so for wiring harnesses, AUX switches, misc, etc and none of that includes labor, i.e. you are doing it yourself.
You really need to ask yourself what do you want to do in terms of off roading. Mall crawlers don't have these dilemmas because they never put strain on their axles... hehehe :)
 
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blkhawk_jl

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We were in the same boat before we decided to just swap out the axles and put D44s in it.

In a nut shell whoever that guy is who told you that is on the right track.
There was another guy on the forum who actually called Dana/Spycer and told them he wanted to run 35s on the D30/35 axles on his Sport. They said if you are just going to mall crawl and do LITE trails you should be fine but beyond that they said you will be running a risk on them.
The solution would be to do an axle disconnect delete in the front and go with chromoly axle shafts both front and rear. But as noted by others your U joints would then become the weak link. Switching to RCV axles up front would really put you in a good spot. Doing that, personally, I'd feel good about gears and even lockers on a beefed up D30/D35 axle set.
A re-gear is going to run you around $2k to have a pro do it or around $1k to do it yourself, approximately. You can pick up a set of factory D44s WITH lockers and 4.10 gears and a two year warranty from a dealer for about $4800. Then tack on another $1800 or so for wiring harnesses, AUX switches, misc, etc and none of that includes labor, i.e. you are doing it yourself.
You really need to ask yourself what do you want to do in terms of off roading. Mall crawlers don't have these dilemmas because they never put strain on their axles... hehehe :)
Thanks for the feedback. I've been trying to decide exactly what i'm going to do. I daily my rig but I do hit the trails on weekends when the weather is nice, i'm in Canada so i'm grounded 6 months outta the year for winter anyway. Big issue for me is if I want to do an axle swap i'm spending at least 5-6k minimum, here in Canada at least, and that's just for the axle lol. Ultimately I worked out a bit of a plan with a local shop. Going to go RCV shafts up front ($1300), get an axle truss & C-gusset kit from artec to help strengthen the axle ($350), and drop a set of 4.56 gears in ($1000). Between those 3 upgrades They should keep the D30 strong enough for a while, I doubt i'll ever be in a situation i'll need a D44 since we don't have very technical or hard trails in Ontario.
 

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Thanks for the feedback. I've been trying to decide exactly what i'm going to do. I daily my rig but I do hit the trails on weekends when the weather is nice, i'm in Canada so i'm grounded 6 months outta the year for winter anyway. Big issue for me is if I want to do an axle swap i'm spending at least 5-6k minimum, here in Canada at least, and that's just for the axle lol. Ultimately I worked out a bit of a plan with a local shop. Going to go RCV shafts up front ($1300), get an axle truss & C-gusset kit from artec to help strengthen the axle ($350), and drop a set of 4.56 gears in ($1000). Between those 3 upgrades They should keep the D30 strong enough for a while, I doubt i'll ever be in a situation i'll need a D44 since we don't have very technical or hard trails in Ontario.
Sounds like you are on the right track for reasonable money. At least you are in the know and can decided what/if anything else needs to be done for the future.
 

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azrubi

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Posted yesterday trying to identify my axles, looks like I've got the M186 front and M200 rear. My local 4x4 shop suggested not to do a regear on the dana 35 and definitely not on the dana 30, instead just save up for new axles all together, purely because they aren't strong enough. I'm not sure if he's basing that decision on the old JK axles.

Looking to go 4.56 or 4.88 with 35's. Anyone have any experience regearing on the 30 & 35?
When replacing your ring and pinion gears with numerically larger ones, the only way they will fit is to narrow the gear teeth. This is the weak link. Measure the tooth thickness between a 4.56 and 3.08 and that will give you an idea on what you sacrifice with regard to durability. That's why people go with Dana 60's or larger.
 

TMJL2018

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I did take a chance and regeared to 4:56 on my Sport running 35's last September. I know enough not to hit it hard, pay attention to my lines, take is easy, and it handles most of the trials around North Texas just fine. I know my own limits and my Jeeps. I wheel at least monthly, sometimes more. I had it professionally installed not wanting to take a chance doing it incorrectly.
 

Therby

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Thanks for the feedback. I've been trying to decide exactly what i'm going to do. I daily my rig but I do hit the trails on weekends when the weather is nice, i'm in Canada so i'm grounded 6 months outta the year for winter anyway. Big issue for me is if I want to do an axle swap i'm spending at least 5-6k minimum, here in Canada at least, and that's just for the axle lol. Ultimately I worked out a bit of a plan with a local shop. Going to go RCV shafts up front ($1300), get an axle truss & C-gusset kit from artec to help strengthen the axle ($350), and drop a set of 4.56 gears in ($1000). Between those 3 upgrades They should keep the D30 strong enough for a while, I doubt i'll ever be in a situation i'll need a D44 since we don't have very technical or hard trails in Ontario.
what shop is this? I live in Kitchener, close to you.

i have sport JL regeared to 4.56 from overdrive newmarket. D44 rear and 30 front.

I also have the artec truss and gussets to weld on the front axle when its warm again.

I’m planning on locking the rear axle, then when time comes getting a new front axle to run 37s

also, you must not wheel much. I can list about 5 trails easily or more where some nice axles and 37s+ would be nice to have for the trails here in ontario.
 

PsychoTrucker81

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Keep your eyes open for used Rubi axles. I am starting to see them pop up more often for not crazy money. This would get you a better gear ratio as well as more strength. Last set was $2k for the pair.

As a re-gear is not cheap it might make more sense to go this way versus sinking money into the D30/35.
$2k?!?! If you find another set that cheap, PLEASE let me know!
 

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$2k?!?! If you find another set that cheap, PLEASE let me know!
WOW!?!?!? $2k is the cost of ONE new axle, picking up a used pair for that price would be amazing.
 

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Jeep’n Jay

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$2k?!?! If you find another set that cheap, PLEASE let me know!
I paid 3k for a set of Rubicon JL axles. I am starting to see others pop up in the 2500-3k range, some slightly more.
 

mgroeger

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Jeep’n Jay

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Jeep’n Jay

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Very decent! Did you need to change the drive lines, or were you able to use the stock Sport ones?
Stock drive lines are fine. The only thing requiring any modification is the front brakes, if you choose to use the Rubi brakes you will have to bend the brake lines. The rear Rubi brakes must be used as the sport ones won't fit the rubi axle but they fit right on. You can use the front sport brakes if you don't want to bend the lines.
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