D30 ring gear casting number....

So i bought this 01 xj a while ago. Lifted, 33's, regeared, ARBs. But the PO was an idiot who just took a loan out any time he wanted something done and paid to have it done for him. He thought he had a teraflex kit when he really had a RE. thought he had a flowtech muffler, really had a flowmaster. Anyways, he didn't know what gears he had in his axles. So i'm putting on a sweet SOLID diff cover today and found this on the ring gear. O30456TJ. Does this mean it has 4.56's in it? Thanks for all the help. It's been bugging me not knowing what gears he had put in it.

I think it would indicate that... if you want to know for sure the ratio just turn the the wheel once and have a friend count how many times the yoke turns. Whats odd is the TJ would seem to indicate a regular Dana 30 Instead of a HP.

nochance9 said:

So i bought this 01 xj a while ago. Lifted, 33's, regeared, ARBs. But the PO was an idiot who just took a loan out any time he wanted something done and paid to have it done for him. He thought he had a teraflex kit when he really had a RE. thought he had a flowtech muffler, really had a flowmaster. Anyways, he didn't know what gears he had in his axles. So i'm putting on a sweet SOLID diff cover today and found this on the ring gear. O30456TJ. Does this mean it has 4.56's in it? Thanks for all the help. It's been bugging me not knowing what gears he had put in it.

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I have no idea what that number means, but the sure fire way to find out is to look at the end of the string of numbers on the ring gear. In most cases will be two numbers indicating the number of teeth on the ring and pinion. For example 41-10, would mean 41 teeth on the ring, 10 on the pinion, thus a 4.10 ratio. If the numbers are not there, count.

ausi02 said:

I think it would indicate that... if you want to know for sure the ratio just turn the the wheel once and have a friend count how many times the yoke turns. Whats odd is the TJ would seem to indicate a regular Dana 30 Instead of a HP.

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Assuming TJ stands for Jeep TJ, that would make sense. He has an '01 which has the same LP D30 the TJs do, not HP D30.

I am going to take a gamble and say that that means you have a set for Dana 30, 4.56 gears, and it’s LP like in a tj.

But really just count the teeth on the pinion and the ring gear and divide

buzzbombxj said:

I am going to take a gamble and say that that means you have a set for Dana 30, 4.56 gears, and it’s LP like in a tj.

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That's what it is. I'd also put money on that being a "D" at the beginning and not an "O". Dana 30, 4.56 ratio, Low Pinion (TJ, as in all TJs had low pinions).

Good point haha. I tried doing the turning the tire thing but i kept getting different numbers of rotation. Does it matter it the opposit wheel is turning the opposit direction when you're doing it? Cause it was when i was trying it. Still have the lines i drew on the yoke and case so i guess i'll try it again while i'm still dirty haha. Also do any of you know much about ARB's?............ Cause i don't, and i just tuged on the air line and it wasn't attached to anything..... I'm assuming that's bad. Unless they work by presurizing the entire case....

The tire turning thing needs to be done with the opposite wheel still on the ground.

As for your air line, that sounds bad. Is it the copper tube that's not attached to anything? That needs to be connected (brazed) to the seal housing that goes on the locker...and the other end goes into a fitting on the differential housing itself. Your *best* bet might be to call ARB and send it directly to the facility in Renton, WA, and have them go through it. They'll get you set up with new seals, check specs on the entire locker, and a new seal housing/copper tube. Call Tech at (866) 293-9078 They'll probably charge a nominal fee and you'll have to pay shipping, but you'll have a factory rebuilt locker and tech advice. Those guys are super helpful.