Project 14 Bolt SF

[99COOP]

Bought myself a 14 bolt sf axle to swap out my 10 bolt with. Plans are to gut the 14 bolt and install 4.88 Yukon's, Detroit Trutrac, Master install kit + axle bearings, disk brake swap, and u-bolt flip kit.

The day i picked it up:



Looking a little shabby, so over the next few months (this is a project i will work on when i'm home during breaks from school) I will slowly rebuild this and get it looking better then new. Should be a huge upgrade over my current 10 bolt.

---------- Post added at 12:01 AM ---------- Previous post was Yesterday at 11:41 PM ----------

This will be the axles home for the winter months as I slowly work on it. The original plan was to blast the axle housing with a sandblaster, but after realizing we would be making a small beach in the workshop I opted to just grind it with a wirewheel from Home Depot.

Heres the start of wirewheeling:


Heres what the gears and carrier look like after I pulled the cover off, overall for roughly 180,000 miles the gears weren't too bad, but the spider gears were chewed up pretty bad which is common:


Since nothing except the axle housing will be reused i pulled everything out not worrying about damaging bearings, shims, gears, etc. Remove the cross pin bolt and then the cross pin shaft, this will allow you to slide the axle shaft in and then pull the C clips out. After pulling the C clips out you will be able to slide the axle shafts out of the housing. I also removed the carrier bearing caps so i could pull out the carrier and gears.



---------- Post added at 12:20 AM ---------- Previous post was at 12:01 AM ----------

I then pulled the axle shafts out. The axle shafts on the SF's are 33 spline and I believe 1.875" in diameter which are a huge upgrade from the small 10 bolt shafts. They are considered reliable for a 38-40" tire which is more then plenty for my application.



After pulling the axles out i pried out the carrier. These can be stubborn but with a pry bar you can slide them out w/ little effort. I wasn't worried about damaging the carrier since i wouldn't be re-using it.


Here's the genius behind the operations:


---------- Post added at 12:33 AM ---------- Previous post was at 12:20 AM ----------

After getting out the axles and carrier i bolted back up the cover (I will be pulling out the pinion at a later time) and decided i would get rid of the broken axle stud.


Further investigation revealed that i would need to replace some more studs because some were stripped pretty badly. I will do this when the time comes though.
I removed the 4 bolts holding the backing plate to the axle flange, these things were a real ***** to brake loose and required alot of leverage, so much so that i snapped my ratchet end completely in half.


The bolts eventually came off and i removed the backing plate. These will be garbage as well because i will be swapping them out for a disk brake set up. Although it will be more expensive to replace and set up, i think in the long run i will be happy to get rid of these over engineered brakes.



---------- Post added at 12:39 AM ---------- Previous post was at 12:33 AM ----------

Hopefully by tomorrow i can get the rest of the axle housing to start looking like this:

Some notes i quickly jotted down for anyone considering this swap, one thing to consider though is the difference in 2wd and 4wd axles. Also GM decided to move the flanges multiple times on the 9.5 sf axles so some people might have different measurements for the flange-to-axle end length.

 

[AtomicHoe094]

nice write up so far!! loving the pictures! about time people use pictures man. Im curious if i can get 5 lug axle shafts for my truck when time to do the 14bolt anyone seen anything like that? i know they made them, but not sure if you can get em aftermarket

 

[99COOP]

^thanks, and i'd have to do a little research on that one. my only questioning would be if they made any 5 lug axles that would be the right length because i know the Chevy 1500 454 SS ran a 14 bolt sf in the back and they were 5 lugs. So if those were 2wd axles i would say the 5 lug would be doable but you might have a harder time finding the axles.

 

[BlueTahoe2001]

Looking Man! Atomic, Moser Engineering can always make axles for a price! lol...

And what are your plans for the Carrier?

 

[99COOP]

Plan to run a Detroit Trutrac, going to avoid running a locker because i really don't want one with as much street driving as i do.

 

[AtomicHoe094]

difference between the 2??

 

[99COOP]

the Trutrac is a posi unit which on the road gives a nearly stock (G80) feeling, but when offroad or in slippery conditions will send the power to the wheel WITH traction compared to the stock G80 which is an open carrier that sends the power to the wheel WITHOUT traction. If you really gas it and both wheels slip the trutrac will power both wheels as well. The locker is awesome offroad, but overkill for my application. With a locker i will get excessive wheel chirp and tire wear, plus some lockers can be expensive like the ARB airlockers.

---------- Post added at 10:13 PM ---------- Previous post was at 10:09 PM ----------

also the Trutracs are a helical gear driven carrier that require no maintenance or rebuilds unlike other posi units that are clutch driven.

 

[ravingmadman]

Dude. This totally turns me on. Good for you for doing this.

Lockers can actually reduce your traction given some applications. a "detroit locker" usually locks the wheels when the gas is applied, but not while coasting. that means that when you're going up a hill, around a corner at high speed, you can lose the rear end, and drift around the corner. which is pretty fscking awesome, if you ask me, but onl;y if you know it's coming. id rather have a true track than a locker just for that reason though. if i want to break the rear end loose, i'll just get on it a little more, and do it proper.

99coop, i have to admit- i thought you were full of poo when you said you were going to do this- not for your ability, but for the time commitment this requires. you're a stud, dude. major props for actually doing this. more props for taking pictures, and helping those of us that will follow.

 

[Cartwright]

Putting a 14bolt under my truck was one of the best things I did to it. I know for a fact I would have destroyed a 10bolt long ago.