(Getting shafted by a) 14bsf build

[4x4blaze]

Hey guys! Been a while since I've been active on here, but I have a question that I know you guys could answer. I've been getting mixed opinions from everyone I ask and it's driving me crazy!

WHICH IS BETTER: 14bsf or a 10 bolt?

I understand the 14bff is the ideal axle for a wheeler, but in my specific application, I believe its unnecessary. I also like my 6 lug 15x10 slot mags.

My truck really goes against the grain of 95% of 4x4 K5 builds. It's a "hot rod" 4wd truck I primarily use as a cruiser. I always jokingly call it an all wheel drive gasser. It's good at nothing, but its a ton of fun! It has a 500hp sbc, performabuilt 700r4, billet 3200 stall converter. Torque and weight is the leading cause of failure for an axle, but this truck is relatively light, and my 33" tires should hopefully be the weak link.

I understand the 14bsf is a much beefier axle, but it does seem like they get a lot of hate. I know a guy who broke his twice with a pooch of a 350 while street driving. He doesn't have the greatest track record with mechanical things though, so take that as you will. & With that being said, I also know a guy with a turbocharged 10 second short bed K10 that ran the 10 bolt for an amazingly long time. It did eventually break and has a 9 inch now, but its also in the mid 9's while making 1100hp.

So.... Im up in the air! What would you guys recommend? Build the 10 bolt or the 14 bolt? How much more hp does the 14 bolt take to turn compared to the 10 bolt?

Thanks in advance!!!

 

[obijuank5]

14 bolt 9.5 is better where it matters for you. Swap it in and don’t look back.
My buddy here in town runs got torque differential and has made some really cool parts for ten second ten bolts.
I’d give him a call or message on Facebook and go over your options. In all honesty you’ll be fine on 33s either way.

 

[Blue85]

I bet a disc-brake 14b s/f has less rotating inertia than a drum-brake 10b. I don't think the drag of the bearings is going to make much difference.

Disclaimer: I am not an axle guru.

 

[Wes Harden]

Yep 9.5" semi float 6 lug disc brake 14 bolt sounds like the ticket.

 

[4x4blaze]

Awesome, my decision is made! Thanks a lot guys!

& Yes, a disc conversion would definitely be part of the swap.. probably a lugnut4x4 kit. My only concern is that my 15s wouldn't clear. The website states a big MAYBE. I suppose thats a problem ill face another day

 

[4x4blaze]

After some research I found this kit:

Single Caliper Disc Brake Adapter 14 Bolt Semi Float 6 Lug Rear

Aftermarket truck parts

cunninghammachine.com

Messaged the owner and he said it *should* work with all 15s without any modification. I'll be the guinea pig and update after I install it. Could be 2 weeks, could be 2 years but I will update here whenever I do. Figured this could possibly help someone in the future.

 

[skunked]

I’m in a very similar situation with my 74 K10 on 15” turbines and I have a 9.5” 6 lug SF axle sitting in the garage for it. I’m surprised the 12 bolt is still holding together….

 

[Wes Harden]

Awesome, my decision is made! Thanks a lot guys!

& Yes, a disc conversion would definitely be part of the swap.. probably a lugnut4x4 kit. My only concern is that my 15s wouldn't clear. The website states a big MAYBE. I suppose thats a problem ill face another day

You may not need or care about a parking brake, the retro fit kits leave a lot to be desired, in the P brake area. Later model gm axle will have the good center of rotor p brake. GMT400 and GMT800 series trucks.

 

[dyeager535]

You may not need or care about a parking brake, the retro fit kits leave a lot to be desired, in the P brake area. Later model gm axle will have the good center of rotor p brake. GMT400 and GMT800 series trucks.

Has anyone found a factory drum-in-hat (DIH) parking brake setup that will fit 15's yet?

I just don't have the time nor money to go to wrecking yards to research, but I did look up a few applications that are DIH, and the 2004 Astro rear rotors were 12.795" OD, 2014 Silverado 1500's are 13.58".

I believe the later 10 bolt rears used the same axle tube OD as the 14SF, which to me indicates the entire 10 bolt rear disk setups could be swapped over by moving the caliper mount, assuming the calipers would clear the wheel ID.

The "offset" (depth of rotor) is 3.35" on the Astro, and 4.1" on the Silverado's, which I'm thinking might push the rotor out far enough that caliper interference could be minimal?

 

[4x4blaze]

I’m in a very similar situation with my 74 K10 on 15” turbines and I have a 9.5” 6 lug SF axle sitting in the garage for it. I’m surprised the 12 bolt is still holding together….

Just checked out your build thread, what an awesome truck man!!!! I love it!

You may not need or care about a parking brake, the retro fit kits leave a lot to be desired, in the P brake area. Later model gm axle will have the good center of rotor p brake. GMT400 and GMT800 series trucks.

Oh yeah? I believe most the "kits" include or recommend Eldorado calipers. Do they just not grab very well? I don't use the parking brake regularly, but it is nice to have when towing it somewhere. & Yes, I'm sure the center of rotor is a far superior design.. my 2005 2500 cummins has that and it seems to work great.

 

[Chickntrk]

Eldorado calipers require constant tinkering and adjustment to keep tight, if you're required to have a parking brake they work well for that, but to actually hold the truck.....ehhhh

 

[Stephen]

Eldo calipers seem to be good for passing inspections. If you want to hold the truck where you stopped it, a line lock is the way to go, either a commercial line lock or a ball valve like the one we carry.

 

[Chevy305]

There's a 14bsf resource thread around here somewhere and it's pretty good with info. But speaking from experience with them, you have 2 options for 6 lug 14bsf. You can take a square body 14bsf and convert it to 6lug or you can get a 6 lug 14bsf from a GMT400 and weld on new spring perches and shock mounts. The latter is the easiest if you have a welder.
The factory 6 lug drums fit 15" wheels no problem and are bigger than the 10b ones and would be considered an upgrade. Not everyone needs rear disks, that said if you're set on disks, you can adapt GMT800 10b disks pretty easily. You'd need everything from the backing plate out though. Spacing from the flange on the axle tube would be the only concern but you can find spacers if needed or you can weld on a new flange.

 

[4x4blaze]

Thanks for all of the info guys! A parking brake isn't a huge concern, but it would be nice to have for certain situations. More of a piece of mind than anything! Well see, I'll have to look into a line lock setup like you guys are describing, it seems like that is the best route.

There's a 14bsf resource thread around here somewhere and it's pretty good with info.

If you find it shoot it on over here! Ironically I've been reading your thread about your 14 bolt in your stepside! Great looking truck & Also, on post #6 I believe I found the "spacers" you are referring to

 

[4x4blaze]

Last night was a good night of wrenching! Ended up getting both my 6 lug semi floaters completely torn down and disassembled. One of them I purchased is beyond repair. Drove 150 miles to buy a "rock solid" axle that ended up being a complete turd. Guy wanted $200 and I ended up getting it for free after he realized I wasn't going to buy it. He begged me to just get rid of it for him!I'm not sure if it was used in a fertilizer truck or a plow truck, but this thing looks like they drug it up out of the ocean. The axle tube underneath the leaf spring mount has a pin hole in it from corrosion. It truly is amazing how bad this axle is.



The other axle is in much better shape and is a perfect candidate for what I'm planning to do. Ordered some really cool ORD spring perches and some shock mounts. Let the grinding begin!

 

[4x4blaze]

& Also, for anyone wondering a fully dressed 14bsf look like it weighs just a hare over 300lbs(Assuming my friends scale is correct)

I honestly expected them to be heavier

 

[fourwheelerjeff]

14 Bolt SF

My question is can I change a 8 Lug to a 6 lug SF? I found one for $200.00 but it is 8 Lug and I'd like to upgrade but keep my 15" wheels.

ck5.com

14SF "tech" info

Didn't ever really come across any posts with a compilation of 14SF tech info. I copied this out of the other post I made, since the old title isn't accurate anymore. This basically is everything I've learned thus far in my 10 bolt to 14SF swap. Hope this info will help people out in the future...

ck5.com

 

[Chevy305]

If you find it shoot it on over here! Ironically I've been reading your thread about your 14 bolt in your stepside! Great looking truck & Also, on post #6 I believe I found the "spacers" you are referring to

Thanks I appreciate that. Unfortunately I lost so many pictures when Photobucket screwed everyone so all my old write ups are basically worthless.

I think that kit you posted should work however it doesn't say what brake parts it uses whether that's square body front caliper or something newer like from a GMT800

 

[4x4blaze]

Happy New years everyone!

Just decided that I would update all of you on a fun little discovery I made! The extra crusty 14 bolt axle was a 4wd (68") axle.. the clean one I was planning on building was a 2wd (63") axle..... When I purchased these axles many years ago I did not know there was a difference. Now I do! And as my luck has it, the unusable one of course is the one I needed... Classic!

But.... this entire ordeal actually ended up working out pretty well! I hopped on marketplace and found a jeep guy selling a k2500 4wd semifloat axle with a brand new never used Yukon posi unit (which was exactly what I was going to buy anyways!) Already had all the mounts ground off as well which saves me a lot of time with the grinder. He was selling the axle and center section for far less than the center section alone is worth! So ended up working out great!

So..... Let's try this again!

Here is a picture of the axle shafts together


And here is the axle that I scored today!

 

[Blue85]

Interesting update. I thought the length differences were never more than an inch or so. What year is the new score axle and width? What years were the first two axles out of? What size are the wheel studs and can you get a matching stud for the front? 2 different size lug nuts isn't the end of the world, but sometimes you can get it to match. Please share tech info in the thread linked above for future reference.