Gear Numbers
 

When I opened my 12 bolt, it had about a pint of gear oil in there.
There were some numbers on the ring X 3817779 14:43 CM 4-69 2

Dose anyone know what that means?

Re: Gear Numbers
 

3817779 is the part number, 14:43means 3.08 gears, i'm guessing the 4-69 is a date code

Re: Gear Numbers
 

14:43 is 3.07 gears. Blue is correct on everything else

Re: Gear Numbers
 

If it has springs inside also ....Does it mean it is a posi?

Re: Gear Numbers
 

yup

Re: Gear Numbers
 

I didn't know if it was just some limited slip or posi....Well that is good cause that is what is going in my truck then

Re: Gear Numbers
 

Your center pin retaining bolt is either broke or missing.

Re: Gear Numbers
 

Good eye.

Re: Gear Numbers
 

Yes it is broke. I found that out when I was removing it to take the center pin out. Half of it unscrewed, and other half is still in the hole. Was told to beat it out, but thats not working, so I have to get an Easy Out to remove it.

Re: Gear Numbers
 

Good LUCK with that one! It has happen to me and it can be a real PITA specially after you have tried to beat the cross pin out. It can be done though I got it in the end. :metal:

Re: Gear Numbers
 

I think 2 days of beating is enough. Time for a new plan.

Re: Gear Numbers
 

3:08's, I think I might as well change those also. With this 283 in my truck, im going to need all the help I can get. Do you guys think 3:55's or 3:73's will be better?

Re: Gear Numbers
 

well, if you spend much time on the freeway, you'd be best off with those 3.07 gears. (the 3.08 was a car gear, 3.07 was for trucks)

Re: Gear Numbers
 

Definately get better gears. That little 283 doesn't have much torque. Go with 3.73''s.

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Dont spend a lot of time on the freeway and besides in Los Angeles, your not going to fast because of traffic. Will 3:73 let me drive the freeway and give me some added torque?

Re: Gear Numbers
 

well, there is another way of looking at this...
the 3.07 is already there. Get your truck on the road now, spend money where it needs to be spent to get you rolling... THEN... if you aren't happy with it... THEN, locate you a 3.73 axle. Your 3.07 is in higher demand for the freeway cruisers, so it'll be easy to sell.
And... we both know, LA isn't ALWAYS grid lock. otherwise, we'd never get the cool videos from the chopper on the scarey police video shows. ;)

Re: Gear Numbers
 

Yes we do have a lot of high speed chases here,..even in traffic.
Not a bad idea, now I have to research which trucks came with 3:73 gears.
I did pull 3:55's (I think thats what they were) from a 6 cyl 68 or 69 C10.
Cant remember and instead of taking the whole rear end. wheels and all, I took out the ring and gears and could not get the pinion out. I hear you dont mix one ring to another pinion. Unless one of you have tried it with no problem.

Re: Gear Numbers
 

If you change gearing above 3.42, you'll need a different carrier all together. Personally, I'd leave it at 3.07 and [assuming you have an automatic] if you want more pick-em-up in your pick-em-up, get a higher stall converter.

Re: Gear Numbers
 

personally, screw setting up gears... esp if you are dealing with old used stuff. I'd just swap the whole rear.
3.73 gears would be in most 3 speed manual trucks, both inline, and small block.
#.73, 3.07, an ocasional 4.10, and I think some big block 3.42 gear sets is all you'll find in a stock 1/2 ton axle. (not sure on the 3.42.. .that may only be in the 3/4 ton and one ton trucks)

Re: Gear Numbers
 

personally id stick with the 3.07's, better mpg city or freeway, but if you do change i wouldnt go any lower then 3.73's and go with a whole rearend and not just the gears, then you know the splines are right and everything

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IIRC, you can pull a rearend out of a newer truck or suv and get the 3.73's and rear disc brakes if you want

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I have a 3.42 posi unit for a 12-bolt.

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ok my 1967 chevy one ton tow the guy that i got my tow truck from when he got it the rear gear was a 538 and engine was a 250 six than the gear was a diffent one add it 456 now i have a 411 gear in it and my enging is a 305 but i will puting in a 292 six than later a 327 or 396

Re: Gear Numbers
 

Is there a formula to help decipher the code on the rear end to help find the gear ratio?
How does 14:43=3.07?

Re: Gear Numbers
 

You can do it, but then you have to fab up the panhard bar mount, and weld on new mounts for the trailing arms.
Disk brakes in the back of a truck is a total waste of money unless you constantly have a lot of weight in it.

none of that matters, we are talking 1/2 ton stuff, those gears were for the heavy trucks, not the light duty stuff.



Yes there is... divide 43 into 14, and you'll get 3.071428571... or 3.07.