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ring gear tooth counts

Kejtar

Kejtar

PostMaster General
NAXJA Member
Location
Westminster, SoCal
Does anyone know how many teeth does the ring gear on a 30 have for
3.55's
3.73's
4.11's?
Same question for the 8.25 for
3.55's
3.73's
4.11's

I want to go junkyard hunting for axles for my dad's jeep and I know that what I'm really interested in are axles from a 2.5l with a manual tranny, but then there is also the tow package ones with 3.73's which might also be desireable, but..... I know that not all of them had deeper geared axles. Plus who knows... maybe I'll come across a regeared jeep?
 
The teeth count are as follows:

3.55=39 ring gear 11 pinion
3.73=41 ring gear 11 pinion
4.11=37 ring gear 9 pinion

It is the same for every front or rearend, regardless of ring gear size. IE Ford 9", Cryco 8.25, ect.
 
XJjeepLess said:
The teeth count are as follows:

3.55=39 ring gear 11 pinion
3.73=41 ring gear 11 pinion
4.11=37 ring gear 9 pinion

It is the same for every front or rearend, regardless of ring gear size. IE Ford 9", Cryco 8.25, ect.
Click to expand...
you da man. Oh and would you know the counts for 3.07's and 4.56's while we're at it? Might come in handy to someone down the road that has to identify gears :D
Thanks
 
Yes sir.

3.07=43 ring gear 14 pinion
4.56=41 ring gear 9 pinion

Ur welcome
deflate.gif
 
I logged on tonight looking for tooth counts so I could finally tell if I have 3.55 or 3.73 when I change the lube this weekend, and this thread was right up top in bold.

NAXJA ROCKS.

Thanks guys.

B
 
ok... 4.11's seem to have more than one choice as there is the 4.10's and 4.11's. 4.11 will have the 37 and 9 count and 4.10's have 41 and 10 (I got a set of axles to prove it too :D)
Sp to recap the list is:

3.07=43 ring gear 14 pinion
3.55=39 ring gear 11 pinion
3.73=41 ring gear 11 pinion
4.11=37 ring gear 9 pinion or 41 and 10
4.56=41 ring gear 9 pinion
 
You are right on the 4.10 or the 4.11. The 4.10 has 41 ring and 10 pinion.

Also there are 3.08 and 3.07 ratios for different rearends.

3.08 has 40 ring and 13 pinion.

3.07 has 43 ring and 14 pinion.

The 4.10 and 4.11 are very close to the same, but dont get them confused, they both have different teeth counts. Its just a different way of adding and subtracting teeth to get the same ratio. Same with the 3.07 and 3.08. They are damn near identical, but the tooth counts are different, and you cannot mismatch them, because the teeth wont mesh correctly.


Any more ratio counts you need to know, just give a shout.
 
I'm taking notes over here for future reference! :D


Just out of curiousity. If I had a 4.10 rear end (which I don't :(), could I just change out the pinion gear from 10 to 9 and then have a 4.56? Or would the gears not mesh correctly?
 
Please excuse my ignorance, if you will. What do you mean by 'pitches'? The angle at which the teeth are ground? From what viewpoint? Looking at the gear from the front, or between the teeth where the two gears mesh?
 
carmike692000 said:
The angle at which the teeth are ground? From what viewpoint? Looking at the gear from the front, or between the teeth where the two gears mesh?
Click to expand...

Your correct on both.

A ring gear that, lets say is 8.5 inches, has a 3.07 ratio, and 43 ring gear teeth, the teeth are going to be at a different angle than that of a ring gear of the same 8.5 inches that has a 4.11 with 37 ring gear teeth. You have to make up the room somehow. Putting 43 teeth on a ring gear requires different angles than it does to put 37 teeth on the same inch(8.5) ring gear. Goes the same for the pinion.

They have different carriers for different ranges of rearend ratios. The GM 12 bolt has series 2, 3, and 4. All for different ratios. The carrier is machined differently to make up for the lack of thickness of different ratios. The pinion head(where the teeth are) is smaller if it has less teeth and bigger if it has more. Thats why the carriers are different to take up the slack between a smaller head or larger one. They also sell ring gear spacers, so you wouldnt have to buy a new carrier, but they kinda suck IMHO.

Its confusing to explain, but if I could show you in person, It would be a lot more easier to explain.
 
the fact that matched ring and pinion sets are made and different pinions of the same gear ratio dont mesh with any gears other than their own would lead me to believe that a pinion not even desgined for that ratio would not mesh at all...
 
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