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Gear ratio doesnt make sense

Blazer guy

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I counted 41 ring and 16 pinion. Doesnt this calculate to a 206?Want to change to 411 OR 456 but not sure of carrier series.
 
First, that calculates to a 2.56 which was available from GM. Have someone roll your tires around 1 revolution and count the driveshaft turns. You should get 2.5 turns if your counting is on.
 
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Yep 2.5 turns.12 bolt rear do i need to changr carrier for 411 or 456 gears?Does detroit locker take place of carrier?Thanks for responding.
 
THOSE NEED TO GO IF THAT IS CORRECT....


What deuche-bag thought that would be a good ratio for a truck needs his head examined....
 
You'll need a new carrier for 4 series gears. A full Detroit locker (not the ez-locker) takes the place of the carrier.
 
Blazer guy said:
Adding the full detroit locker at time of gear change.So i dont have to worry about the 4 series carrier?

Yup. Make note that the truck 12bolt is different from the car 12bolt. You'll find something like this:

Detroit locker for GM truck 12 bolt 3.73 and up.

The "3.73 and up" lets you know what series carrier the Locker is based on. Keep in mind this is only an example and your locker dealer should have the specific details.

Some gear sets are bastardized. What I mean is the ring gear is made extra thick so it will work with a lower series carrier. Don't buy bastardized gears if you can help it. The higher the ratio, the smaller the pinion gear because the ring gear is a fixed diameter. The smaller the pinion gear, the weaker the pinion gear.

I personally would look at using a corporate 14 bolt for anything over 4.10 but that's just me.
 
ssls6 said:
I personally would look at using a corporate 14 bolt for anything over 4.10 but that's just me.

i secend that . if hard core is in the works get 14ff for all out strenght . 10 and 12 bolts are to small on pinon gear to hold the big power and thay will spit the teeth off the ring gear if used hard or behind high hp motor.
 
If you go with a detroit just order the one for the gears you're using and you'll be fine.

Either way that 2.56 carrier is garbage and of no use to you.
 
need 4 series carrier, thats not whats in there now,

this makes about 4th or 5th 2.56 axle ive seen or heard having been found in a gm truck
3.40 and 3.42 have been the rarest around here, ive only found one of each so far, 77 and 80 respectively, both 12 bolt

what year make model is the truck

good luck

happy birthday tomorrow btw :D
 
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Since your running 35" tires i dont think a 14B is needed. You would be doing alot more diff dragging but it has its advantages. If you got a 14b/d44 from a 3/4ton you could have 4.10 gears for a lot cheaper.


Later
 
yup what he said, for just about 500.00 give or take you can snag some 4.10 geared 3/4 tons. saves you some $$$$$$$$$$$$$

then sell yoy current stuff:D
 
Thanx Randy.the truck is an 81 k5 350/350TH/208 10b front 12b rear.256 gear is a mind blower.Would have thought atleast 308s.So thick gears in the front with no locker?Will write up alittle more on this 81 project later and will have alot more ?s.Thanks for the help and a heck of a sight
 
R72K5 said:
this makes about 4th or 5th 2.56 axle ive seen or heard having been found in a gm truck
3.40 and 3.42 have been the rarest around here, ive only found one of each so far, 77 and 80 respectively, both 12 bolt

what year make model is the truck

I've got 3.42s in my '80 K-10 and 2.76s in my '89 Blazer. Ain't I the lucky one?
 
Thanks but no thanks. The K-10 is headed for the scrap yard, so I'm stealing the 3.42s off of it until I can find some better axles (an M1008, if I'm lucky).
 
no i was just saying that to add to your mental info of whats out there. haha o.k. it was gone a long time ago.
 
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