Gear Swap

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JRB

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Put an indicator mark on the ring gear and spin the pinion side by hand.

Less than 4 full revolutions of the pinion side will be 3.73's and slightly over 4 will be 4.10's, a good way to confirm you got what you paid for.

(3.73 revolutions for those gears and 4.1 for that set of gears if not clear)

I don't know the tooth count for these gears, but beings two signs of 3.73 is leaning towards that, do the above to see what you ended up with.
 

duderz7

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I've got a 3.73 ring and pinion in the garage that I could go compare numbers to, but the above suggestion might be the best way to tell. I am pretty sure mine was stamped with the ratio on it, but that doesn't necessarily mean yours is.
 

RockinRam96

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Put an indicator mark on the ring gear and spin the pinion side by hand.

Less than 4 full revolutions of the pinion side will be 3.73's and slightly over 4 will be 4.10's, a good way to confirm you got what you paid for.

(3.73 revolutions for those gears and 4.1 for that set of gears if not clear)

I don't know the tooth count for these gears, but beings two signs of 3.73 is leaning towards that, do the above to see what you ended up with.
I don't know why I didn't think of doing this trick the other day, when I had them apart. I will try it out, but I am pretty certain I have 3.73s.

I called the junk yard that I bought these axles from. Spoke to the same salesman, he is looking for a set of 4.10s for me. Said he will figure it out and get me what I need.
 

lfhoward

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Saw a 4 cyl KJ being sold on Craigslist for $700 for parts. That would have your 4.10’s. It’s in CT, which might be near you depending on where you are in NY.

 
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RockinRam96

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Saw a 4 cyl KJ being sold on Craigslist for $700 for parts. That would have your 4.10’s. It’s in CT, which might be near you depending on where you are in NY.

I don't know why I didn't think of doing this trick the other day, when I had them apart. I will try it out, but I am pretty certain I have 3.73s.

I called the junk yard that I bought these axles from. Spoke to the same salesman, he is looking for a set of 4.10s for me. Said he will figure it out and get me what I need.
I appreciate it. Too bad it has a mechanical lien on it.
 

RockinRam96

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Well I am on my 2nd set of axles from a junk yard that were supposed to be 4.10. Both sets i got ended up being 3.73, which are no use up me.

It’s a little disappointing, first I’m getting down to crunch time on a trip. And second, this last set looks great!
 

RockinRam96

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and I have a set of diffs ( front and rear ) and no one seems to want LOL
Strange world isn't it
In 4.10? You're in Southeastern Ohio, correct? I do get out that way somewhat often. Lets talk.

Can you message on this forum? Send private messages. I'll give you my phone number to call or text.

Zach
 

turblediesel

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In 4.10? You're in Southeastern Ohio, correct? I do get out that way somewhat often. Lets talk.

Can you message on this forum? Send private messages. I'll give you my phone number to call or text.

Zach
Click on tommudd's username and then "start conversation". To view answers or the whole conversation click on the envelope at the top of the screen.
 

tommudd

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In 4.10? You're in Southeastern Ohio, correct? I do get out that way somewhat often. Lets talk.

Can you message on this forum? Send private messages. I'll give you my phone number to call or text.

Zach
Yes 4.10
Yes Southeastern Ohio
out in the woods LOL
 

Jeremy6305

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Dana was the only manufacturer who made the 4.10s for the D30a
lots of places advertise they have them but do not actually know what they are saying
4 cylinder gassers are around and not that hard to find really
I have people call me every once in a while when finding them
Have you tried car.parts.com ?
They ship if not local
Just a question, do you think the 4:56 will kill highway mileage? I am running lt265/75r16. I cannot find any 4:10 for the 30a online. It appears Dana Spicer has stopped producing them.
 

duderz7

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I believe 4:10 is the largest (numerically) ratio that can be put into the 30a. Even if you could find a new one the price would likely cause you to p**p yourself. Do some junkyard searching and pickup an intact front diff you'll save many hundreds of dollars not to mention paying someone to setup your gears.
 

Jeremy6305

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I believe 4:10 is the largest (numerically) ratio that can be put into the 30a. Even if you could find a new one the price would likely cause you to p**p yourself. Do some junkyard searching and pickup an intact front diff you'll save many hundreds of dollars not to mention paying someone to setup your gears.
Well I finally got to tech support at Dana Spicer Ann got a part number 84006-5 (4:10). They are pricey $500 to $900 depending on the vendor. That is just ring and pinion gear no bearings or seals.
Putting them on a open diff shouldn’t be that difficult.
 

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