which 14 bolt?

[XHitman396]

ill start off with saying i know next to nothing about rear-ends, im not gonna lie. so now that swapping in a 14bff has become a reality, i need to know what to look for. lets start off with what the difference is with 9.5", 10.5" and i think there's 1 more, im assuming bigger # the stronger? but what exactly is it measuring, and which are easier/cheaper for upgrades (lockers, gears, etc)? second off, what year would be the easiest swap, on some dont you have to change shock mounts or something? and are there good/ bad years like a 700-r4 has? and how bout dimensions, aren't dually's shorter, and with like vans or something? thanks for the "14 bolt 101" class guys.. haha

 

[Hossbaby50]

To swap a 14bff into an 87K5 you would want a 14bff from a 3/4 ton truck. The spring perches are in the same location between 1/2 and 3/4 ton. 1 ton's are in a different location. For shock mounts to match you will want one from a 3/4 ton 4x4.

Van an dually's have different widths and spring locations I believe and are a little more involved to swap in.

The difference between a 14bff and sf are the sf has a 9.5" ring gear and is a semifloating axle. This means the axleshaft takes the weight of the truck instead of the axle tube. The 14bff is stronger and cheaper to regear and lock. The 14bsf is lighter and give more ground clearence, but weaker.

If you break a 14bsf axle you will have the same problem as a 1/2 ton axle. The tire and wheel will try come off the truck. Good luck breaking a 14bff axle, and even if you did it would still stay where it was at.

There is an 11.5" 14bff but that is in new Dmax trucks and really hasn't been swapped much yet. Alot more work for not much gain over a 14bff. It may be a stronger then a 14bff 10.5" but people run 44's with big motors and dont break 14bff 10.5" axles.

Harley

 

[tRustyK5]

9.5" 14 bolt is a semi-floater. This means the axle shafts also help support the weight of the truck as well as transmit power to the wheels. At the brake drum it will look very similar to your current 10 bolt. It has a 9.5" ring gear and 'C' clips that hold the axle shafts in place. locker selection is pretty good, but most of them will replace the entire carrier so they're not especially cheap. It has 33 spline axle shafts, and I can't recall the shaft diameter off the top of my head.
Overall a good upgrade from the 10 bolt and probably what GM should have used from the factory IMO.

The 10.5" 14 bolt is a full floater. That means the axle shaft does not support any vehicle weight, it just transmits power to the wheels. The weight of the truck is supported by a spindle and bearing set-up that the axle shafts pass through. From the outside you'll see 8 bolts attaching the end of the axle shaft to the drum/hub. It has a 10.5" ring gear and 30 spline 1.5" diameter shafts. They can be broken but it takes a lot of power and big tires in the right conditions to do so. Less locker selection, but the most popular one is a lot cheaper for the 10.5" 14 than for any other diff. The Detroit locker for the 14 can be installed in the factory open carrier...easy install and a lot cheaper than having to replace the entire carrier.
There are a couple of popular widths and configurations, but the easiest to swap into a K5 is a 14 FF from a 3/4 ton 4x4. The 3/4 tons shared the same perch width as well as shock mount location. One ton vbersions will need perches moved as well as shock mounts.
3/4 ton 2WD versions will only need shock mounts modified.

HTH.

Rene

 

[K5MONSTERCHEV]

There is an 11.5" 14bff but that is in new Dmax trucks and really hasn't been swapped much yet. Alot more work for not much gain over a 14bff. It may be a stronger then a 14bff 10.5" but people run 44's with big motors and dont break 14bff 10.5" axles.

Harley

I found one for CHEAP once, but I didn thave money at the time. Next time I see one im snatchign it up! Beefy as hell and disc brakes (w/ebrake) already!

 

[XHitman396]

Harley, Rene, that pretty much answers any question i may have had, and then some.. much appreciated, time to shop... thanks again..