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14 bolt SF 6 lug axle years that work best under a K5?

51K views 73 replies 12 participants last post by  nascarfreak88 
#1 · (Edited)
Setting up a 14 bolt SF 6 lug axle under a K5

Edit(2-5-12) I've found the axle I needed out of a 90 3/4 ton 4x4. Now I need to see how to set it all up!!! I'll update the first post with stuff I find out or still have questions about or the questions that have been figured out!

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So far these are the things I've discovered or stilll have questions about.

My 10 bolt spring pad width is 42.5"?

80-87 3/4 ton Suburbans 14 bolt SF are 8 lug only.
88-98 3/4 ton Pickups/Suburbans SF 6 lug 2wd. ( Narrow axle. Clisess to stock rear 10 bolt axle. )
88-98 3/4 ton Pickups/Suburbans SF 6 lug 4wd. 68" width ( wider axle, matches to front 10 bolt width)

What upgrades are more available if there is a difference? Should I get open carrier or is the gov-lok plenty strong for now?

Purchased Spring perches an shock tabs and new ubolts from www.offroaddesign.com for the swap.

What about pinion angle! I purchased an angle finder to help get the angle matched to the 10 bolt.

Thanks!!
 
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#3 ·
I heard the 88-98 2wd 6 lug SF 3/4 ton trucks axles are narrower than the stock 10 bolt by 1.5", while the 4x4 3/4 ton trucks axles are 3" wider than the stock 10 bolt which should make them line up with the front 10 bolt perfectly!

I can't verify any of this is true!!???? So I'm going to measure them in the field an install another 10 bolt in the time being to get my truck back up an running while I still search for the correct 14 bolt SF an get my info gathered and my ducks in a row!

So if anyone knows to true info on the 14 bolt SF axles let me know!!!!
 
#4 ·
I used the sf14b from an 88 heavy half ton in my 91 k5. It looks like it came stock in the blazer now...

Got a disk brake kit from gubni:
http://www.pirate4x4.com/forum/showthread.php?t=746609

Ruff stuff spring perches:
http://www.ruffstuffspecialties.com/catalog/14BSS.html

And a slip yoke eliminator:
http://offroaddesign.com/catalog/NP241SYEkits.htm

Then a custom rear shaft from a local fab shop. I am curious though if the stock shaft would of worked if I had swapped the yoke from the stock rear 10b to the "new" sf14b... Therefore not "needing" the sye
 
#6 ·
I am curious though if the stock shaft would of worked if I had swapped the yoke from the stock rear 10b to the "new" sf14b... Therefore not "needing" the sye
What? I am understanding that you thought the 14SF having a different yoke meant needing to get a SYE?

FWIW, the driveshaft length doesn't need to be changed going from a 10B to a 14SF. All you need to change is the axle end U-joint. Also, the 10B yoke will bolt to the 14SF, but there may be an issue with the pinion seal.
 
#5 ·
2WD 88-98 6 lug 3/4 ton - 65" WMS-WMS
4X4 88-98 Z71,4X4 - 68" WMS-WMS
88-98 6 lug 3/4 ton Van - 68" WMS-WMS

The truck axle has a 47" perch width. The van is around 50" IIRC. The axle has 1350 yoke so a conversion joint will be needed.

As for price, the Z71 axle will be the most expensive because the salvage yards think there is something magical about Z71 that makes this axle worth $500 more than it really is. The best bang for the buck is the van axle because it is NOT a Z71 axle and is 68" wide. All options have equal aftermarket support.
 
#61 · (Edited)
Great Thread Mav2u !!!

Also good tip there axis. Nice to know the Van has the proper length axle too and cheaper. Not only cheaper, I'd say the Van is much more apt to be an Open Diff than a Gov-Lok since most years, Z71 package includes locking diff which is the Gov Bomb junk. I'd prefer a lunchbox over a G80 Gov-Bomb so the Van's are what I'll be looking for.

I'm going to be going to a salvage yard this morning for this same type of swap, putting a 14B SF in place of a 10 bolt rear axle in an 85 K1500. Now I already have 2 8lug Semi Floats out of an 84 and 85 3/4 ton 2wd Squarebody trucks that are open and have the 4.10 gear ratio I want. Perches would already be matched up and save me some cash if I don't have to buy the whole axle.

Am I understanding that if I got just the axle shafts, backing plates and brakes off an 88-98 6 lug 3/4 ton van, or 88-98 4x4 6 lug truck, those axles and backing plates will bolt up and fit my Squarebody 14b SF axle housing? And I need to avoid 2wd axle shafts since they'd be to short correct?
 
#8 ·
Oh, so basically because the 14SF had a bigger yoke, you thought you needed a new driveshaft? Since you were doing the driveshaft you thought to do the SYE to kill 2 birds?

All you needed was conversoin u-joint. You didn't have to mod the driveshaft. What threw was saying that you NEEDED the SYE.
 
#10 · (Edited)
Thanks everyone!!

I picked up a 14 SF out of a 4x4 90's truck with the needed 3.73 an a gov lok! Got it for cheap so I'll live with the gov lok for now!

I plasma cut off all the perches an shock mounts! Ground down the metal to a smooth axle surface!

Going to order new perches an shock tabs from www.Offroaddesign.com or the ruff stuff place mentioned above. Haven't decided yet!!

So how do I figure out where to put the perches an tabs so they are correct? I just centered everything up based off the 42.5" on center for the spring pads!

Also, what about the angle of the pinion? I got 6 degrees on mine do that is what I'll go with on the new axle!
 
#11 · (Edited)
New axle getting ground smooth with my angle grinder!!



Grinding down the left tube smooth for the mounting of the perches an shock tabs. Prepping it all for the welder!



Now just need to figure how to put the perches an shock tabs in the right location for the welder to weld the correctly!

Also need get the pinion angle so perches, shock tabs, an drive shaft are all in the right place an angle!!!
 
#12 · (Edited)
I have to take the axle to a local welder. So I'll be taking the 10 bolt along for reference with the welder.

How do you know the pinion angle is correct? I used my angle finder an got the correct angle.
 
#13 ·
I have to take the axle to a local welder. So sliding it under the truck is not an option an leaving it.

How do you know the pinion angle is correct?

How else can I figure it out an keep everything setup to take to the welder?
Do you own an angle finder? If not, get one.

If your old axle is out of the truck, set it on some jackstands with a jack under the housing. Set the angle finder on a spring perch and adjust the jack till the angle finder reads 0*. Once this done, set the angle finder across the flats on your pinion yoke. Whatever it says will be your pinion angle.
 
#14 · (Edited)
The old axle is still under the truck. I purchased an angle finder so I'm set for figuring out angles!

I've ground down the new axle, it is ready for the perches an shock tabs. I just need to order them now. Also need to find new upper spring mount plate since all I have is the one on my 10bolt, an that definitely won't fit!

Need to order drum rebuild kit, as I won't be able to afford the disc brake conversion just yet! Need to find some more about the 14 bolt SF disc brake conversion with the e-brake. I have to have a functioning e-brake on my rig!

So if anyone knows links to a 14 bolt SF with e-brake kit please post the link. I see plenty of bolt on FF kits but no SF bolt on kits!
 
#17 ·
I don't own an angle finder. The old axle is still under the truck.

I'll look into getting an angle finder, hopefully they aren't to much coin.

I've ground down the new axle, it is ready for the perches an shock tabs. I just need to order them now. Also need to find new upper spring mount plate since all I have is the one on my 10bolt, an that definitely won't fit!

Need to order drum rebuild kit, as I won't be able to afford the disc brake conversion just yet! Need to find some more about the 14 bolt SF disc brake conversion with the e-brake. I have to have a functioning e-brake on my rig!

So if anyone knows links to a 14 bolt SF with e-brake kit please post the link. I see plenty of bolt on FF kits but no SF bolt on kits!
I found that Home Depot, Grainger, an Northern Tools around me sell a cheap $10 angle dial tool. I'm guessing that should work!
 
#15 ·
The ruff stuff kit has everything you need for mounting....

From the ruff stuff page:

http://www.ruffstuffspecialties.com/catalog/14BSS.html


2 leaf spring plates for 2.5" springs
2 perches for 3 3/8" axle tube and 2.5" wide
2 shock brackets 1.5" ID
4 U-bolts 10"x5/8"x3 3/8" and hardware

As far as the e brake, I searched and searched till my eyes bled, and the only affordable disk brake kit I could find was the one from gubni. You can run the eldorado calipers, but I didn't mess with it at all. I have park... If I had to do it again, I would only order his brackets, bolts, wheel studs (or atleast get the part #) and the braided steel lines, then get everything else locally.
 
#16 ·
Only thing is I have a 3 inch lift kit with a 3 inch lift block on the back. I hate to pay for the ubolts I'm never going to use. They don't seem to sell the stuff in the kit separately! I'm sure the ubolts are like $40.00 bucks of the price!!!

Is the Eldorado ebrake setup the only option to go with on a 14 bolt? No other cheaper e brake options? Those Eldorado ebrake calipers are expensive an hard to find complete!!
 
#19 · (Edited)
I wonder how an extra inch in the rear will look, seeing that I have a 3 inch block installed. Their shackle kit gives a 4 inch lift. Wonder if it would really hike the rear up or not?

Actually, I wonder if just adding the 14 bolt gives me extra lift???? Since the tube is technically bigger than the 10 bolt???

Looks like I can order the spring perches from offroaddesign.com an the ubolts with top plate an the shock tabs. Looks like they have all the parts I need sold separately so I can build my own kit!!!! :)
 
#23 · (Edited)
Well I ordered the parts from Www.offroaddesign.com today.

Got my:
- Axle spring perches
- Shock tabs
- Upper ubolt plates for 14 bolt rear
- Ubolts for for the Tuff Country 3" rear block lift I have!

All ordered up an on the way!

Still researching the disc brake with ebrake option! It won't make the initial install, but I will plan on doing it later when I get more funds!!! Looks like a rear brake drum rebuild is my next task!!!
 
#24 ·
If you still have the old rear axle installed, take your spring pad angles and pinion angle off of the old axle and transfer it to the new one. If you install the new axle under the truck, you can set your angles and tack weld all your brackets. Then you can load it up and run it down to the welders shop. If you have no welder at all, install the axle under the truck set all your brackets and mark them with a paint pencil. Then take it to the welder and have him line everything up and weld it.
 
#25 ·
I was actually thinking about finding a person who does on sight welding.

Do they cost way more than taking it of a welders shop?

Yeah, I got the angle gauge today an measured 6 degrees at the pinion angle an 11 degrees on the drive shaft angle.

I wire wheeled the whole axle today, took off the brake lines an the Brake cylinders.


Going to order the brake drum full rebuild kit tomorrow. Might as well make the brake drums work as old as possible with new parts.

Thinking about getting some of that POR-15 black paint rust proofer to paint the axle with! Looks like a good product to paint the axle an get a nice black paint look that will last. Long time!!
 
#26 ·
Thinking about getting some of that POR-15 black paint rust proofer to paint the axle with! Looks like a good product to paint the axle an get a nice black paint look that will last. Long time!!
Only if you prep it right. If you're not prepared to spend the time to do so, you're better off spray bombing it on a regular basis. Proper prep means sanding the axle with 80 grit. POR needs roughness to mechanically adhere to the surface. Smooth metal, even with their Prep & Ready, won't guarantee good adhesion, whereas a rough surface works every time.
 
#31 ·
Well I am sandblasting the axle also after I get the brackets welded on.

Think sandblasting be enough for the POR-15 to stick? Or still needs an 80 grit sand job?
 
#32 ·
Sandblasting is fine, but the shit needs to be clean. Contrary to popular belief, solvent, lacquer thinner, and such don't clean for shit. They degrease, but they suck at picking up and suspending dirt. You need to wash it with detergent and water. A cap full of laundry detergent in a bucket of water works good. POR Marine clean works really good. I have also found that using their Prep & Ready (or any other brand of phosphoric acid based metal prep) helps too. Then it's ready for POR.
 
#33 ·
Who the fuck are you building this for? Your grand kids' grand kids? Paint that fucking thing black and be done with it! You are over killing it at a cost that could be applied to something else. I have never seen an axle, at least one that's not sunk in the dirt and left for dead, rust in half. Flap disk/primer/paint! Why is this so difficult?
 
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