Largest tire size for Dana 30

[DMF]

I also need tires soon and really want to go with 37" but have a D30. Can't upgrade both at the same time. Would it be safe to use a D30 and 37" in areas like Last Chance Canyon. I just want to gauge what type of trails I can do besides the mall with that setup until I can afford the upgrade.

 

[David1tontj]

I've never really understood this. Is it that the wheels are heavier? It's not like the sprung weight of the jeep is changing? Is it something to do with torque & tire revolutions per foot changing? Sorry, I'm a newb & I've read a bunch of threads. All say it'll break, none explain real well why.

There are several reasons.

the gear ratio required for 37s, leaves you with a tiny pinion gear that has tiny teeth, therefore you are prone to breaking your ring and pinion. 4:88 seems to be about as low as you want to go. 5:13 s are pushing it.

The added weight of the tire makes them harder to turn, but indoor think this matters quite as much.

I feel like the biggest reason, is simply the additional leverage that the larger diameter tires have on the axle. If you know anything about leverage, you'll understand how much additional force even a few inches can add.

Hope this helps.

 

[Slappy32]

Locked, 5.38's and 40's. 1440 driveshafts as well.

Anything worth doing is worth overdoing.

I'm with you on that one. It will be built over time for budget reasons. Just looking to get a base sport JKU on a better stance in the mean time. I'm thinking 33's on 17" rims. Ratio will be 3:21 or hopefully 3:73.

As for wheeling, it will be in the South Florida area, so lots of mud and not lots of rocks.

 

[DWiggles]

If you know anything about leverage, you'll understand how much additional force even a few inches can add.

Hope this helps.

OP, Get your rachet and a TIGHT bolt (preferably a skid plate bolt under your jeep) now hold the ratchet very close to the socket and try REAL hard to break the bolt loose, it wont budge, now move your hand out 2.5" from the socket and try again REAL hard, if it breaks loose :clap2: tighten it back up and move to another bolt, regardless, now move your hand out another 2.5" from the socket (5" total) and try to break loose the bolt, pretty easy. -> this is exactly whats going on with bigger tires on an axle, Leverage :shock: Your hand on the wrench represents where your tire hits the ground, and breaking the bolt loose represents breaking your axle... crude but very real example of the difference in forces 5" can make. (That's what she said?)

 

[DMF]

Yup, 35's are definitely in my future. Thanks for the explanation.

 

[David1tontj]

The little one is bigger than a d30. It's a d35. Just so you know how tiny those things are.

 

[MedixJK]

OP, Get your rachet and a TIGHT bolt (preferably a skid plate bolt under your jeep) now hold the ratchet very close to the socket and try REAL hard to break the bolt loose, it wont budge, now move your hand out 2.5" from the socket and try again REAL hard, if it breaks loose :clap2: tighten it back up and move to another bolt, regardless, now move your hand out another 2.5" from the socket (5" total) and try to break loose the bolt, pretty easy. -> this is exactly whats going on with bigger tires on an axle, Leverage :shock: Your hand on the wrench represents where your tire hits the ground, and breaking the bolt loose represents breaking your axle... crude but very real example of the difference in forces 5" can make. (That's what she said?)

Thats actually a great representation. Leverage.

 

[hhunter050]

I have a d30 stock and I'm running 37s no problem and I wheel the shit out of mine. It's hard to break an axle so unless you are jumping your jeep you shouldn't have to worry about breaking anything for a long time.

 

[MedixJK]

I have a d30 stock and I'm running 37s no problem and I wheel the shit out of mine. It's hard to break an axle so unless you are jumping your jeep you shouldn't have to worry about breaking anything for a long time.

Its not just the axle that is the problem. If the op is on a budget, the last thing i would do is suggest running 37s on a d30.

 

[ridg3runner]

I have a d30 stock and I'm running 37s no problem and I wheel the shit out of mine. It's hard to break an axle so unless you are jumping your jeep you shouldn't have to worry about breaking anything for a long time.

Either you're a major badass or you're just delusional. There's more than enough photo evidence on this site to prove you wrong, you know that, right?

 

[07JKSahara]

I have a d30 stock and I'm running 37s no problem and I wheel the shit out of mine. It's hard to break an axle so unless you are jumping your jeep you shouldn't have to worry about breaking anything for a long time.

Please define, wheel the shit out of?

 

[David1tontj]

I have a d30 stock and I'm running 37s no problem and I wheel the shit out of mine. It's hard to break an axle so unless you are jumping your jeep you shouldn't have to worry about breaking anything for a long time.

Well... Stock Is actually better than say.. 5:13s.

Jumping is how you bend them.

Wheeling hard, is how you break them.

When yours breaks, not if, but when, then you will know what it's like to wheel hard.

It's fine If you want to wheel on a stock 30, but don't let people think it's okay to wheel the shit out of it. That's bad advice. Got any pics of your crazy off-roading?
Edit: while on a d30

 

[hhunter050]

I'm sorry fellas. I know I'm riding a thin line. What I should've said is I'm running 37s on a stock d30 cause I'm waiting on it to break. My grandpa always said if it ain't broke don't fix it and I live by that! Anyways definition of wheeling the shit out of is some weekend rock crawling. So basically a bit more than the average "trail rider".

 

[07JKSahara]

I'm sorry fellas. I know I'm riding a thin line. What I should've said is I'm running 37s on a stock d30 cause I'm waiting on it to break. My grandpa always said if it ain't broke don't fix it and I live by that! Anyways definition of wheeling the shit out of is some weekend rock crawling. So basically a bit more than the average "trail rider".

I can actually respect that. I too have a d30 for a time, but I baby it pretty well.

 

[hhunter050]

I can actually respect that. I too have a d30 for a time, but I baby it pretty well.

I baby mine on the trails. I should've said I wheel pretty hard to be riding on a stock d30 and 37s. Not trying to stir up anything and yes I gave bad advice. Try your hardest not to have 37s with a stock d30

 

[ArmyofMike]

Either you're a major badass or you're just delusional. There's more than enough photo evidence on this site to prove you wrong, you know that, right?

I wheel uber hard on my D30. True Story! I got pics and pics. Just tell me which curb you want to see it on: Target? Home Depot? Bed Bath and Beyond? I've hit all the urban trails.....dog.









:bleh:

 

[David1tontj]

I'm sorry fellas. I know I'm riding a thin line. What I should've said is I'm running 37s on a stock d30 cause I'm waiting on it to break. My grandpa always said if it ain't broke don't fix it and I live by that! Anyways definition of wheeling the shit out of is some weekend rock crawling. So basically a bit more than the average "trail rider".

Fair enough. That's what I did for a while. But I got sick of fixing broken axle parts, so I went one ton.

And it's not hard to break them if you get in the right (wrong) spots.

This is my front d60 shaft after I got under an undercut rock and it just popped. Not wheeling hard in my book.

 

[hhunter050]

Well I exaggerated my wheeling the shit out of so I'll take the blame but I will have to say it has gone through a lot more then I ever would have thought. Also still running stock gears. Waiting on them to give also. I know it could be extremely bad if on the trails and anything blows but I'm a gambler and a risk taker so I'll let y'all know when this shit gives way.

 

[hhunter050]

Fair enough. That's what I did for a while. But I got sick of fixing broken axle parts, so I went one ton.

And it's not hard to break them if you get in the right (wrong) spots.

This is my front d60 shaft after I got under an undercut rock and it just popped. Not wheeling hard in my book.

View attachment 136484

I'm just extremely cautious when it comes to choosing lines and what not. I know something like this could easily happen

 

[hhunter050]

Either you're a major badass or you're just delusional. There's more than enough photo evidence on this site to prove you wrong, you know that, right?

I'm a major badass lol and yes I know