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73-87 Chevy _ GMC Trucks => 4 Wheel Drives => Topic started by: moneyg77 on January 14, 2015, 01:59:59 am

Title: 10 bolt vs 12 bolt vs 14 bolt?
Post by: moneyg77 on January 14, 2015, 01:59:59 am
So im in need of a rear end rebuild. I have an 81 k10 longbed stepside 350,4spd, 208 w/ 6'' lift and 35's . For the longest time ive been debating just rebuilding my current 10 bolt w/ 3.73's vs finding a 12 bolt (which i found 2, $170 per). then i found a 14 bolt from a chevy van 2500 for $150 on cl. Any suggestions? All help is appreciated.
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: Irish_Alley on January 14, 2015, 05:41:18 am
i would go with the 14 bolt BUT its going to be a 8 lug axle. then you need to match the ratio so you need to buy a 8 lug front axle. then you need new tires/rims
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: moneyg77 on January 14, 2015, 06:54:43 am
Why would I need new tires?
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: Irish_Alley on January 14, 2015, 07:55:22 am
16" rims for the ¾ vs 15" for the ½ ton. you can get 15" 8 lug but now your talking about more money
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: Jason S on January 14, 2015, 09:14:45 am
i found a 14 bolt from a chevy van 2500 for $150 on cl.

You might want to check overall width and spring spacing for the van 14-bolt before purchase. I seem to recall there were some differences between the truck and van axles... 

Since you're looking and researching, many of the 88-up Chevy/GMC light duty 2500 (and some 1500 trucks) had a 6-lug, semi-float 14-bolt rear axle. It would be stronger than the 10 or 12-bolt, but it'd require moving the spring hangers and shock mounts. 
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: Irish_Alley on January 14, 2015, 02:51:29 pm
88+ are a different width i think
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: moneyg77 on January 14, 2015, 08:47:09 pm
Ok, so it might be a no go. His 14 bolt is off of an '01 chevy van..i might just go with the 12 bolt posi's i found.
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: Jason S on January 14, 2015, 09:47:41 pm
88+ are a different width i think
There is a slight difference in the 88-up truck versus the 73-87. 

Ok, so it might be a no go. His 14 bolt is off of an '01 chevy van..i might just go with the 12 bolt posi's i found.
My $0.02,
If you're going to keep the 6" lift and 35's, then a 14-bolt would be the better long term solution. 

Here's a recent thread in case you missed it:  http://forum.73-87chevytrucks.com/smforum/index.php?topic=30117.0;topicseen (http://forum.73-87chevytrucks.com/smforum/index.php?topic=30117.0;topicseen)
Title: 10 bolt vs 12 bolt vs 14 bolt?
Post by: roundhouse on January 15, 2015, 09:33:18 am
http://offroaddesign.com/catalog/14boltspringperches.htm

Buy these

Cut off the old ones
Bolt the 14 ff under your truck with the driveshaft installed and get he pinion angle wjere it should be and tighten down U bolts

Have a mobile welder come over and weld it

We are doing that now.  But I actually found non running a k10 wih a FF14 in with the perches and shock mounts relocated and the hub modifed so the wheel has  the same  width as the front axle
 so we bought it as a parts truck 

   
You will have to get  different rims and maybe different tires
You can buy aftermarket steel 15" rims that are 8 lug
But sometimes 15" won't fit on a FF axle and you also gotta swap the front hubs and rotors to 8 bolt

Someone on pirate is selling a kit to convert the FF14 to 6 lug AND disc brakes for about $350

That's a deal. You're gonna spend more than that switching to 8 lug rims
Plus 16 inch tires cost $100 each more than 15"s


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Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: ehjorten on January 15, 2015, 09:36:32 am
If I was going to do something custom and put a little bit of welding work into it to make it fit, I would do the AAM 14-bolt axle out of the 2001 and newer trucks.  There are 2 versions: the 2nd generation 11.5 AAM and the 3rd generation 10.5 AAM.  These axles are similar to the Corporate 14-bolt, but they do not have the support bearing for the pinion like the Corporate 14-bolt.  These axles have the advantage of having factory disc brakes and also the ability to run an e-locker!
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: Irish_Alley on January 15, 2015, 07:20:17 pm
by time you do all this you could buy a matching set of 8 lug axles for $250-$500 but then you have to get new rims and maybe tires. you can pick up a matching 6 lug for prob a little less then the 8 lug axles and keep your rims and tires and be done
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: roundhouse on January 16, 2015, 09:20:43 am
Yep
We swapped in 8 lug axles
Before I realised that 16 " tires are $100 more than 15s

What a ripoff.   There is actually LESS material in the tire but it costs more

Every inch increase in rim diameter above 15 adds $100 to a tire

We blew two 12 bolts driving totally normal on paved roads with 33s

So no real choice but to go 14 bolt
Silly me.   Thought a 12 bolt was as good as a 9" ford


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Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: moneyg77 on January 18, 2015, 01:32:16 am
Im kind of excited guys, for once in all the chaos. I found dana 44/14ff axles off of a 77 3/4 ton. I also found 8 lug 15" wheels in the same town my parents live. Did I find something promising? I started a separate post asking what I should offer for the axles. They have 3.73 gears and came off of the same truck. Thanks
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: Irish_Alley on January 18, 2015, 02:17:57 am
how much are they asking?
i think a good price is $250-$300
cant remember since its been so long but i picked my set up with 4.10 for 200 or 300 at a junkyard. knew the people and one boy who worked there was my childhood best friend and he was at one point (when his dad passed) co-owner of the place.
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: moneyg77 on January 18, 2015, 02:48:06 am
They're asking 500 for the axles and 150 for the wheels, two different sellers
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: Irish_Alley on January 18, 2015, 03:07:41 am
i would try to talk him down. the most i would pay is 400. that being said offer him 300
Title: 10 bolt vs 12 bolt vs 14 bolt?
Post by: roundhouse on January 18, 2015, 06:07:14 am
15" 8 lug wheels are rare

And also may not fit over the calipers on the front



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Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: Irish_Alley on January 18, 2015, 08:42:49 am
grind the calipers
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: moneyg77 on January 18, 2015, 07:45:20 pm
i would try to talk him down. the most i would pay is 400. that being said offer him 300

After some back and forth we finally agreed on $450. This guy DID NOT want to budge on the price..which is understandable. And the reason he sold them at that price is because he has 6 dana 44's, 4 14 bolt ff, and 2 14 bolt sf.

He bought the axles from a friend of his. I guess the story is that guys engine blew and was so pissed that he parted out his entire truck. IMHO, what a stupid decision!! But worked out for me, since they were on a daily driven truck just a couple months ago..not sinking in dirt for 15 years like another set that I found.

15" 8 lug wheels are rare

And also may not fit over the calipers on the front



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I was able to get the wheels for $100. He had 3 sets of them. The ones I bought were sandblasted and powder-coated black.

grind the calipers

Where should I grind? Is there a link to pics of where they should be grinded?
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: Irish_Alley on January 18, 2015, 09:20:18 pm
the reason he has so many is because hes asking too much lol.

now this is for a dana 60 its the same ideal but the 60 is thicker so you have to grind more off you wont have to grind this much

(http://www.pirate4x4.com/tech/billavista/60_front/caliper%20grind%203.jpg)
(http://www.pirate4x4.com/tech/billavista/60_front/images/caliper_grind_1_small.jpg)
i would imagine it amount also depends on your back spacing on your rims also.
do you know what it is?
http://www.pirate4x4.com/tech/billavista/60_front/index2.html
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: moneyg77 on January 21, 2015, 01:01:47 am
I was finally able to take the rear diff cover off and I am shocked!!!!
(http://tapatalk.imageshack.com/v2/15/01/20/c43f8c76e7e3d582779a18fd4b964a55.jpg)(http://tapatalk.imageshack.com/v2/15/01/20/a91c25ce7fdbb2e8c2a87420a57ba353.jpg)(http://tapatalk.imageshack.com/v2/15/01/20/ad88e3008fdef00d1ef2f546f564a8bb.jpg)(http://tapatalk.imageshack.com/v2/15/01/20/34125d35c8d7e302ea1384a80cb655a4.jpg)
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: moneyg77 on January 22, 2015, 12:09:01 am
From what I could get without removing the ring and pinion, the numbers on the ring gear read (41 10 81 (41/10=4.10)) and the pinion (10 15 41 (41/15=2.73)). When I get pictures I'll post them of the numbers i could see. Anyone know what those numbers mean? Hopefully im wrong but it looks like theres a 2.73 pinion matched to a 4.10 ring gear...please please tell me i'm reading wrong or ive mistakenly did the math with the numbers.
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: Irish_Alley on January 22, 2015, 12:21:19 am
if you count the teeth on both and divide 41 by the pinion number it should tell you
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: Irish_Alley on January 22, 2015, 12:21:43 am
also you might want to check your front now
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: roundhouse on January 22, 2015, 07:09:55 am
Here's a chart
http://www.quadratec.com/jeep_knowledgebase/article-137.htm


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Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: roundhouse on January 22, 2015, 07:14:23 am

From what I could get without removing the ring and pinion, the numbers on the ring gear read (41 10 81 (41/10=4.10)) and the pinion (10 15 41 (41/15=2.73)). When I get pictures I'll post them of the numbers i could see. Anyone know what those numbers mean? Hopefully im wrong but it looks like theres a 2.73 pinion matched to a 4.10 ring gear...please please tell me i'm reading wrong or ive mistakenly did the math with the numbers.
how many teeth on each one ?

Use a grease pencil or fingernail polish to mark one tooth do you can count em

Mine was easy since it was missing half a tooth on the pinion


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Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: moneyg77 on January 22, 2015, 06:57:23 pm
i counted the pinion/ring gears and they are matching 2.73 gears
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: moneyg77 on January 23, 2015, 01:32:33 am
So for the replacement Dana 44 and 14 ff that I'm installing is there anything I should know(steering, suspension, brakes...anything)?
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: Irish_Alley on January 23, 2015, 04:16:00 am
http://forum.73-87chevytrucks.com/smforum/index.php?topic=28592.0
this is about brake systems.
plastic reservoir its a JB3, JB5 or JB6
JB3 BRAKE, POWER, DISC/DRUM, 4600 LBS
JB5 BRAKE, POWER, DISC/DRUM, 6400 LBS
JB6 BRAKE, POWER, DISC, DRUM 7200 LBS

so your setup should be good with just swapping axles. steering should all be the same and so should suspension.
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: moneyg77 on January 23, 2015, 04:56:53 am
That's good news! Which brakes do you recommend?
Title: Re: 10 bolt vs 12 bolt vs 14 bolt?
Post by: Irish_Alley on January 23, 2015, 05:53:31 am
what ever comes on the axles. being ½ ton you should have 4600lbs (JB3) the ¾ will be anything above that (JB5, 6, 7 or 8) so you should be good with what ever comes on them