85mudblazin
1/2 ton status
What the title says.
14bff
14bff
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
Difference between thick or regular gears??
- Thread starter 85mudblazin
- Start date
84_Chevy_K10
Banned
Thick gears use a thicker ring gear so you can run lower (numerically higher) gear ratios with the 4.10 and down carrier.
Otherwise you need to buy a 4.56 up carrier.
Otherwise you need to buy a 4.56 up carrier.
84gmcjimmy
1 ton status
Yeah, like tim said they just let you use lower gears in a higher gear carrier.
Uhh, one is thicker than the other? /forums/images/graemlins/eek.gif /forums/images/graemlins/wink.gif
Take a look at the pinion gear on a 3.08 gear set. It has a lot of teeth and the gear end is pretty large in diameter. A pinion gear for the exact same axle, but for perhaps a 4.56 ratio will have fewer teeth and the gear end will be much smaller in diameter. As the pinion gear gets smaller, the ring gear has to move closer to the centerline of the pinion shaft in order to mate with the ring gear. On many axles there are 2 different carriers to accomodate the various gear ratio sets that are available. For example, on a 14-bolt full floater, one carrier was used for all gears of 4.10 and (numerically) lower (3.73, 3.42, etc), while another carrier was used for all gears of 4.56 and (numerically) higher (4.88 and 5.13). The difference between the two carriers is that the one used for 4.56-5.13's has the ring gear shifted closer to the pinion centerline. However, aftermarket companies sell "thick" 4.56-5.13 gears for that rear end that have the difference in the ring gear shift added to the backside of the ring gear. So when one of those gears is bolted to a diff that was designed for the 4.10 carrier, the ring gear and pinion will mesh properly. (While if you tried to use a thick 4.56 on a carrier that was designed for the 4.56 factory gears then the ring gear would never line up with the pinion gear.
Take a look at the pinion gear on a 3.08 gear set. It has a lot of teeth and the gear end is pretty large in diameter. A pinion gear for the exact same axle, but for perhaps a 4.56 ratio will have fewer teeth and the gear end will be much smaller in diameter. As the pinion gear gets smaller, the ring gear has to move closer to the centerline of the pinion shaft in order to mate with the ring gear. On many axles there are 2 different carriers to accomodate the various gear ratio sets that are available. For example, on a 14-bolt full floater, one carrier was used for all gears of 4.10 and (numerically) lower (3.73, 3.42, etc), while another carrier was used for all gears of 4.56 and (numerically) higher (4.88 and 5.13). The difference between the two carriers is that the one used for 4.56-5.13's has the ring gear shifted closer to the pinion centerline. However, aftermarket companies sell "thick" 4.56-5.13 gears for that rear end that have the difference in the ring gear shift added to the backside of the ring gear. So when one of those gears is bolted to a diff that was designed for the 4.10 carrier, the ring gear and pinion will mesh properly. (While if you tried to use a thick 4.56 on a carrier that was designed for the 4.56 factory gears then the ring gear would never line up with the pinion gear.
84_Chevy_K10
Banned
If you tried to use thick 4.56s in an axle with the 4.56 up carrier I doubt you could even install the carrier all the way as it'd be hitting the pinion.
Interesting tech fact...Ford does not use carrier breaks. You should see how thick the 3.73s are in the 7.5" in the back of my DD.
Interesting tech fact...Ford does not use carrier breaks. You should see how thick the 3.73s are in the 7.5" in the back of my DD.
85mudblazin
1/2 ton status
ok so the 14bff that I am buying has 3.73 gears does that mean I cant go lower than 4.10 gears?
84_Chevy_K10
Banned
You can put whatever gears you want in it up to 5.13s by using a thick gearset for 4.56, 4.88, or 5.13.
[ QUOTE ]
ok so the 14bff that I am buying has 3.73 gears does that mean I cant go lower than 4.10 gears?
[/ QUOTE ]
Sure you can go lower, but you'll have to buy thick gears to fit that particular carrier if you want 4.56's, 4.88's or 5.13's. /forums/images/graemlins/thumb.gif
ok so the 14bff that I am buying has 3.73 gears does that mean I cant go lower than 4.10 gears?
[/ QUOTE ]
Sure you can go lower, but you'll have to buy thick gears to fit that particular carrier if you want 4.56's, 4.88's or 5.13's. /forums/images/graemlins/thumb.gif
84_Chevy_K10
Banned
/forums/images/graemlins/thinking.gif /forums/images/graemlins/whistling.gif
For a good article on carrier breaks and why they exsist click here: http://www.randysringandpinion.com/tech/tech.asp and then click on the "Do I Really Need to Buy Another Carrier*" link on the page that comes up. /forums/images/graemlins/thumb.gif
