Gears & Axles Driveshafts | Rearends | Differentials | Gears | 12 Bolt | 9 Inch | Dana

Do 3.73 make the 10 bolt weaker?

Thread Tools
 
Search this Thread
 
Old 09-20-2009, 12:25 PM
  #1  
TECH Resident
Thread Starter
iTrader: (2)
 
taws6's Avatar
 
Join Date: Mar 2006
Location: England
Posts: 899
Likes: 0
Received 0 Likes on 0 Posts
Default Do 3.73 make the 10 bolt weaker?

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
Old 09-20-2009, 01:56 PM
  #2  
TECH Regular
iTrader: (2)
 
cmb570's Avatar
 
Join Date: Sep 2007
Posts: 428
Likes: 0
Received 0 Likes on 0 Posts

Default

subscribing
I was thinking of do same but with 3.90
Old 09-20-2009, 02:12 PM
  #3  
11 Second Club
iTrader: (36)
 
Magnet's Avatar
 
Join Date: Sep 2004
Location: Fort Myers Florida
Posts: 4,075
Received 69 Likes on 50 Posts

Default

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..
Old 09-20-2009, 03:21 PM
  #4  
12 Second Club
 
john shea's Avatar
 
Join Date: May 2004
Location: hazelwood,Mo.
Posts: 656
Likes: 0
Received 0 Likes on 0 Posts
Default

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.
Old 09-20-2009, 03:47 PM
  #5  
11 Second Club
iTrader: (18)
 
danhr's Avatar
 
Join Date: Apr 2006
Location: Ford City, PA
Posts: 447
Likes: 0
Received 1 Like on 1 Post

Default

Originally Posted by john shea
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
Old 09-20-2009, 04:43 PM
  #6  
TECH Resident
Thread Starter
iTrader: (2)
 
taws6's Avatar
 
Join Date: Mar 2006
Location: England
Posts: 899
Likes: 0
Received 0 Likes on 0 Posts
Default

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?
Old 09-20-2009, 04:45 PM
  #7  
TECH Apprentice
iTrader: (5)
 
k0261886's Avatar
 
Join Date: Feb 2008
Location: Michigan
Posts: 397
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by john shea
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.
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.
Old 09-20-2009, 05:03 PM
  #8  
11 Second Club
iTrader: (18)
 
danhr's Avatar
 
Join Date: Apr 2006
Location: Ford City, PA
Posts: 447
Likes: 0
Received 1 Like on 1 Post

Default

Originally Posted by k0261886
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.
Old 09-20-2009, 05:29 PM
  #9  
TECH Resident
Thread Starter
iTrader: (2)
 
taws6's Avatar
 
Join Date: Mar 2006
Location: England
Posts: 899
Likes: 0
Received 0 Likes on 0 Posts
Default

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
Old 09-20-2009, 05:40 PM
  #10  
11 Second Club
iTrader: (18)
 
danhr's Avatar
 
Join Date: Apr 2006
Location: Ford City, PA
Posts: 447
Likes: 0
Received 1 Like on 1 Post

Default

Originally Posted by taws6
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.
Old 09-20-2009, 06:05 PM
  #11  
TECH Resident
Thread Starter
iTrader: (2)
 
taws6's Avatar
 
Join Date: Mar 2006
Location: England
Posts: 899
Likes: 0
Received 0 Likes on 0 Posts
Default

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?

Last edited by taws6; 09-20-2009 at 06:11 PM.
Old 09-20-2009, 11:10 PM
  #12  
Staging Lane
 
turningfast's Avatar
 
Join Date: Jan 2006
Posts: 88
Likes: 0
Received 0 Likes on 0 Posts

Default

The smaller the pinion gear the less tooth contact with the ring gear teeth, smaller pinion is weaker.
Old 09-21-2009, 04:57 AM
  #13  
TECH Resident
Thread Starter
iTrader: (2)
 
taws6's Avatar
 
Join Date: Mar 2006
Location: England
Posts: 899
Likes: 0
Received 0 Likes on 0 Posts
Default

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

Sorry for being slow
Old 09-21-2009, 06:30 AM
  #14  
11 Second Club
iTrader: (18)
 
danhr's Avatar
 
Join Date: Apr 2006
Location: Ford City, PA
Posts: 447
Likes: 0
Received 1 Like on 1 Post

Default

Originally Posted by taws6
Quick question: Is it bad to jack the car from the housing?
no

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

yes
Old 09-21-2009, 06:51 AM
  #15  
TECH Resident
Thread Starter
iTrader: (2)
 
taws6's Avatar
 
Join Date: Mar 2006
Location: England
Posts: 899
Likes: 0
Received 0 Likes on 0 Posts
Default

Many thanks, appreciate the help
Old 09-21-2009, 07:27 AM
  #16  
TECH Apprentice
iTrader: (18)
 
lordrazo's Avatar
 
Join Date: Feb 2005
Location: florida
Posts: 397
Received 0 Likes on 0 Posts

Default

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
Old 09-21-2009, 07:34 AM
  #17  
Staging Lane
 
Drift_king2007's Avatar
 
Join Date: Jun 2009
Location: Waco, Texas
Posts: 84
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by lordrazo
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
Old 09-21-2009, 07:45 AM
  #18  
TECH Resident
Thread Starter
iTrader: (2)
 
taws6's Avatar
 
Join Date: Mar 2006
Location: England
Posts: 899
Likes: 0
Received 0 Likes on 0 Posts
Default

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....

Last edited by taws6; 09-21-2009 at 07:51 AM.
Old 09-22-2009, 10:36 PM
  #19  
TECH Regular
 
NAAllTheWay's Avatar
 
Join Date: Feb 2009
Location: Geneva, IL
Posts: 426
Likes: 0
Received 0 Likes on 0 Posts
Default

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.
Old 09-22-2009, 10:40 PM
  #20  
TECH Regular
 
NAAllTheWay's Avatar
 
Join Date: Feb 2009
Location: Geneva, IL
Posts: 426
Likes: 0
Received 0 Likes on 0 Posts
Default

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


Quick Reply: Do 3.73 make the 10 bolt weaker?



All times are GMT -5. The time now is 04:04 PM.