Hi,

Will 3.73 make my 10 bolt weaker?
I was intending to swap gears and do the ring and pinion, bearings and T/A cover and do c-clip eliminators whilst in there.
So will the 3.73 make my 10 bolt rear end weaker?

Thanks for the advise

 

subscribing
I was thinking of do same but with 3.90

 

I'm no guru, but I have heard changing to a lower gear puts more stress on it, but I would love to hear an educated response..

 

I believe the simple answer is yes, because as the number of teeth on
the ring gear get higher the thinner they get and are more prone to break.

 

what he said

 

Okay, thanks for your replys.

Please excuse my ignorance, but what is it in the 10 bolt that normally breaks?
Is it the gears that I'm thinking of replacing?

 

Actually, that is incorrect.

Axle Ratio ........Tooth Combination
2.56:1..............41,16
2.73:1..............41,15
3.07:1..............43,14
3.08:1..............40,13
3.08:1..............37,12
3.31:1..............43,13
3.36:1..............37,11
3.42:1..............41,12
3.55:1..............39,11
3.73:1..............41,11
4.10:1..............41,10
4.11:1..............37,9

As you can see, 2.73, 3.42, 3.73, and 4.10s all have 41 ring gear teeth. Also, I believe that it is common knowledge that less teeth= better because the teeth are bigger and stronger. As you can see, this is also incorrect, since the higher in gear ratio you go there are less teeth on the pinion gear.

 

you forgot the ring/pinion combination that he more than likely has. 3.23's. The ring/pinion combination for that is 42/13.

 

So my 3.23 gears have 42 ring gear teeth, and 3.73 have 41. That would lead me to think the 3.73 would be stronger as they have less teeth = bigger + stronger. Or do I have it wrong?

Is it the gear teeth that normall break in a 10 bolt?

Thanks for your input

 

yeah that's right.

and no, it's not the gear teeth that directly break on the 10 bolt. Usually the axle housings start to bend, breaking the axles, carrier, etc. the ring/pinion usually breaks from the case of something else breaking. That's why people install the t/a girdle kit.

 

Uhh, I think I'm understanding....

So by swapping in 3.73 I'd actually be strenthening my 10 bolt?
(Plus I'd be swapping in the other bits too FWIW).

Surprising to think of the forces they must get to make the housing actually bend

Quick question: Is it bad to jack the car from the housing?

 

The smaller the pinion gear the less tooth contact with the ring gear teeth, smaller pinion is weaker.

 

So the 3.73's would be stronger than my 3.23's ?

Sorry for being slow

 

no

[QUOTE=taws6;12251647]So the 3.73's would be stronger than my 3.23's ?
QUOTE]

yes

 

Many thanks, appreciate the help

 

Its a 10 bolt 3.23 or 3.73's either way its not to big of a difference in strength in my opinion I ran a stock rear with 3.73 and a4 to 500 hp never broke till the th400 and t brake my opinion just put the gears in and enjoy till it breaks then go 12 bolt like I did

 

X2^ I have the 4.11 gear set, and like said above mine is a 37, 9 tooth combo. I have done quite a couple of 4k drops no prob LOL

 

Great, thanks for the reassurances

BTW a 12 bolt would cost me around $7000 with importing costs, hence my cautiousness. I might get lucky and pick up a used 10 bolt here if the worst did happen, but why buy it if I don't need it, I already have a house load of crap! lol....

 

not to complicate things....but a taller gear will make the car move out faster...so in a sense the faster the car moves out, the less the resistance put on the drivetrain as a whole....kinda complicated but think of the strain on your shoulder if you were to jack up a semi with a 2ft long pipe on your jack....probably quite a bit.....now take that same jack, same semi and make the pipe 8ft.....it is going to put a lot less strain on your shoulder.(same theory as a breaker bar)....kind of hard to relate but if u can grasp the concept you will get what i mean...weather the actual gears are "stronger" or not is one concept, but if it takes less strain on those gears to make your car move out, thats a whole nother way of looking at it.....my bet, a 323 will break before a 373.

 

that should make sense, if not think of it this way....if u have a 10 speed bike and you are riding up a super steap hill....1st gear shoots u up the hill....if u try it in 10th the bike creaks and with enough force the chain is going to snap, same principal