14 Bolt Full Float / Semi Float Identification

[HotRodPC]

For those who are not aware. Very easy to tell the difference in a 14 Bolt Full Float and a 14 Bolt Semi Float.

Full Float has the axle hub sticking out of the drum or wheel.
Full Float is a 10.5 inch Ring Gear and doesn't require C clips.


Semi Float DOES NOT have the hub sticking out of the drum or wheel.
Semi Float is a 9.5 inch Ring Gear and uses C clips in the carrier to retain the axles.

Here is a photo of the rear covers to help you ID the different 14 bolts. Very easy to tell the difference.

This is what G80 Locking Diff Gov Lok Carrier looks like in a 14b FF.

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[1low4x4]

Thanks for the tip. Can you elaborate more on what is special about both, I.e. What makes one better than the other, and what are each designed to do?

 

[crazy4offroad]

14b SF is the in-between for the 10-bolt and the D60. They dont have full-floating axleshafts like the 14b FF does. Meaning the wheel hubs ride on bearings attached to the axleshafts, where the FF has axleshafts that pass through the hub and have no vertical load on them at all, just rotational load. Also I believe the SF has a 9.5" ring gear and the FF has a 10.5" ring gear.

 

[HotRodPC]

14b SF is the in-between for the 10-bolt and the D60. They dont have full-floating axleshafts like the 14b FF does. Meaning the wheel hubs ride on bearings attached to the axleshafts, where the FF has axleshafts that pass through the hub and have no vertical load on them at all, just rotational load. Also I believe the SF has a 9.5" ring gear and the FF has a 10.5" ring gear.

Yes, you are right. 9.5inch ring gear in the 14B SF. The SF also uses C clips to keep the axles in. It comes in both 8 lug and 6 lug varieties. So it makes a great upgrade if you have a K10 and want to go to a stronger rear axle. You just have to find the 6 lug axles for it then you can keep you front axles to same also. The most common ratio in the SF for a Square body version is 4.10 and next to never came with a G80 Locking Diff from the factory. I think it was about around 81 when GM went to the SF for standard OEM equipment in the 3/4 tons. If you got the 14B Full Float in a 3/4 after that, you normally had the Heavier Duty RPO code.

The 14b FF is the most preferred for strength, has floating axles that do not need C clips since the outer hub bolts are what hold the axles in. Pure brute strength in axles and 10.5 in ring gear and why all the rock crawlers want 14b FF. I'd say its strgegth falls between Dana 60 and Dana 70. Just a good rock soldi axle for light trucks up to 1 ton. This is also what the military used in its CUCV's.

 

[bucket]

I'd like to point out that the 6 lug version was only used in the newer body style trucks. Spring perch relocation is required for installation in a square body. It also was available as a 5 lug, but only in the 454 SS.

 

[RetroC10Sport]

Wish I had a pic of the rear end in a 1970s Cadillac hearse...You want to talk HEAVY DUTY with a 5x5 pattern...I think it would be possible to put one in a SB, but not sure if any posi or lockers are available for it as I don't know who made it.

 

[HotRodPC]

I'd like to point out that the 6 lug version was only used in the newer body style trucks. Spring perch relocation is required for installation in a square body. It also was available as a 5 lug, but only in the 454 SS.

I have heard this before too. I have also heard both ways also, that the axles from the NBS will fit the SB rear end, and I have also heard they will not.

 

[bucket]

I have heard this before too. I have also heard both ways also, that the axles from the NBS will fit the SB rear end, and I have also heard they will not.

A member on CK5 did the shaft swap, it's not a direct replacement. IIRC, it involved mixing and matching drums and brake parts, as well as spacing out the backing plates.

 

[HotRodPC]

A member on CK5 did the shaft swap, it's not a direct replacement. IIRC, it involved mixing and matching drums and brake parts, as well as spacing out the backing plates.

Sounds like it might be easier just to relocate the spring perches.

 

[saveitforsunrise]

New here, first post, the 14 bolt sf will not fit in a sb without relocation of spring perches and shock mounts, the 14bsf out of a obs truck is also slightly wider by around 3 inches iirc, so if you have a 4x4 the axle width matches better for the 10 bolt fronts, if you go out and look at your stock 4x4 the rear is narrower than the front, this really helped the looks department with me, is you look down the side of my truck now both tires acctually line up!!!

 

[HotRodPC]

New here, first post, the 14 bolt sf will not fit in a sb without relocation of spring perches and shock mounts, the 14bsf out of a obs truck is also slightly wider by around 3 inches iirc, so if you have a 4x4 the axle width matches better for the 10 bolt fronts, if you go out and look at your stock 4x4 the rear is narrower than the front, this really helped the looks department with me, is you look down the side of my truck now both tires acctually line up!!!

This all depends which SF you have. Squares came from the factory with 14b SF since 1981 so they do fit and bolt right in, if it's a squarebody OEM SF axle.

I've been told the 88-98 2wd rear axles are 3 inches to narrow, but the 4wd 88-98's are the same width 68 inches wms to wms (wheel mounting surface) but yes, they'd have to have the spring perches relocated to put a 88-98 SF axle in a Squarebody truck, burb or blazer/jimmy.

 

[Grater]

Hey guys! Just wandering can I fit drum brake hardware kit from k30 with full floater axle to my Suburban with semi floater? they have same 13" drums

 

[HotRodPC]

Hey guys! Just wandering can I fit drum brake hardware kit from k30 with full floater axle to my Suburban with semi floater? they have same 13" drums

No. Because of the hub that sticks out of the FF. You're axles wouldn't be long enough either.

 

[TRokk]

I have a 14b back axle that has a ratio of 3.73, but also guys its an 8 lug, 3/4 ton axle.
so this would be a FF right?

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And the number's on the right side, I don't understand what they are supposed to mean?

 

[crazy4offroad]

The 10 bolt front is used for both 1/2 and 3/4 ton trucks, with only the hubs different for the lug patterns. 1-ton has the Dana 60.