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Confused about axles.

Looks like you have a good starting point. :)

1) Transfer case: Those trucks should both have NP208 transfer cases, but they probably have different input shafts (function of which tranny is in front of it). If so, you will hafta swap the shafts before you can swap them, but that should be all you need to do if you choose to do that swap. But what (specifically) is hard to shift?

Do you have any reason to rebuild your axles? Since you aren't talking about gear-swapping, and the axles appear to be in good shape, why would you bother pulling them apart? :dunno: If you decide that you just hafta put in 6-lug shafts (or you want a locker), then you might as well go through the rear end, as you'll hafta open it up to remove the axle shafts. But you really don't have any reason to open the front unless you think there is a problem. Swapping from 6-->8 lugs (or vice versa) is easy on the front (only one step more than changing brake rotors, as the caliper backing plate also has to be changed). To explicitly answer your question, yes, the gears will swap into your existing front axle, but it is probably a bunch easier to swap axles and then install your 6-lug hubs & backing plates. No axle disassembly required. Unless you're wanting to replace bearings and seals pre-emptively.

Lockers. What is your purpose for this truck? A Detroit locker (and similar units) will be locked by default (can be good or bad depending on what you want to do). A positraction unit will not lock, but does feature some torque distribution. A factory gov-lock will be unlocked until slippage occurs and then lock up (like a Detroit) when needed. They're pretty neat units. The 10-bolt 1/2-ton gov-lock carriers like to fragment (:doah:), but the 14bsf and 14bff units seem to have a decent reputation. The truetrac is somewhere between the Detroit-style lockers and the clutch-style posi units. It will lock up, but defaults to being open. And evidently it doesn't always engage right away (search through the Garage section for a recent thread on this topic).



The parking brake doesnt work on my main rig, but does on the donor.

1.) Transfer case: On the donor, when I shift from 2wd to 4hi, it is a smooth gliding feeling. When I shift in my rig, I have to yank down with moderate force to have it engage (about the same pressure as using a floor jack?)

Decided to just swap front/back axles for now based off responses. Seems like I will already be out of my comfort zone doing the swap ... let alone attempting to rebuild/regear axles. Another day for the rebuild, unless need necessitates. Ill keep the 8 lugs on my rig for now and see if I can source some cheap wheels or fork out 100ish per for my current ones (pro comp matte black D window.. ) Cheaper then buying new axle shafts @ 122 per .

Brakes kinda sucked on the donor.. spongy and took 2-3 pumps to engage (I wouldn't know what worn rotors/pads looked like.. so i should probably just rebuild these for safety purposes any how)

tires are too large to fit the donor wheels. (and the donor wheels are pretty wrecked and rusted looking) I will worry about this after I successfully swap axles.

Lockers: Purpose of truck is to do more trail/rock crawling. I'd like to maybe mess around in moab this summer (6 hour drive).
 
I went to attempt the swap today and ran into a little snag. I have (2) sets of 6 ton jack stands which were too short to reach the frame rails. (3 ton each... Kind of dumb that they are labeled 6 ton, but i digress)

So, I ended up swapping the bumpers instead! (Maybe I will be more inspired, now that I think it looks cooler)

I was researching prices of taller jack stands and was a little dismayed. I then came across cribbing. Is it safe? The idea would be to make a platform out of some 4x4s and rest the jackstand on top of it.

https://paulhasenmeier.wordpress.com/2011/12/05/cribbing-for-heavy-vehicle-lifting/

Am I just being cheap? There are tons of images online of people with lifted rigs and cribbing, but I will be under the vehicle and my life/limb is important to me.

I have used some huge logs as jack stands before when taking frames out from under a truck--ones at least a foot in diameter and cut as squarely as possible so they wont rock around..

When I had to pull (drop !) the engine in my old '63 VW Beetle,I took a ride to a local sawmill and asked if I could get two big hardwood logs to put under the rear wheels,they guy sold me two about 18" in diameter and about the same height--I was able to drive the car up on them using 2x12's as ramps and that lifted it high enough to get the motor out from under it..

Cribbing is sturdy and safe if done right--I'd look for some videos of those guys who move buildings or do foundation repairs to see how to stack and secure the timbers properly..
 
I've seen people use them on 2.5ton M35's and 5ton wreckers which are MUCH heavier than anything on this board. Also, seen them used when lifting houses... Haven't done it myself, but will be swapping axle this weekend and was thinking about the same thing. Thanks for the link.
 
The parking brake doesnt work on my main rig, but does on the donor.

1.) Transfer case: On the donor, when I shift from 2wd to 4hi, it is a smooth gliding feeling. When I shift in my rig, I have to yank down with moderate force to have it engage (about the same pressure as using a floor jack?)

Decided to just swap front/back axles for now based off responses. Seems like I will already be out of my comfort zone doing the swap ... let alone attempting to rebuild/regear axles. Another day for the rebuild, unless need necessitates. Ill keep the 8 lugs on my rig for now and see if I can source some cheap wheels or fork out 100ish per for my current ones (pro comp matte black D window.. ) Cheaper then buying new axle shafts @ 122 per .

Brakes kinda sucked on the donor.. spongy and took 2-3 pumps to engage (I wouldn't know what worn rotors/pads looked like.. so i should probably just rebuild these for safety purposes any how)

tires are too large to fit the donor wheels. (and the donor wheels are pretty wrecked and rusted looking) I will worry about this after I successfully swap axles.

Lockers: Purpose of truck is to do more trail/rock crawling. I'd like to maybe mess around in moab this summer (6 hour drive).

The smooth gliding feeling is how it should be. Again, are you saying it's hard to yank while you're moving, or while you're still? If you're spinning up a front driveshaft that was stationary, it will take some time and some pressure (more time than pressure, so be gentle). If it's hard to pull while you're stationary, that is not proper.

What transmissions do the trucks have? You may well be able to simply bolt the donor case into your rig and side-step this problem. But it sounds like the donor is a 3-speed and your truck is a 4-speed. These trannys use different output shafts, so you will hafta take the input shaft out of your transfer case and install it in the donor case before you can mate it to your tranny.

If you're intimidated by axle swapping, you might be happier off skipping the rebuild. But if you're going to want to change gears or add a locker, now is the time to do it. Much easier to do that work when it's NOT underneath the truck.

New brakes are a good idea.

In what dimension are the tires too large to fit the donor wheels?
 
Yes, the donor is a 3spd auto and my rig is a 4spd auto.

The stock 85 came with 15x6's, so I swapped to i believe 16x8s or 16x7s (I don't remember now and the size isnt listed on my bill of sale). I had assumed the 81 was also smaller width wise...sounds like I am wrong?

I am shifting while in neutral. Also, in my rig when going from 4 Hi to 4 lo, there is a brief gear grinding noise during the shifting only (Similar sound to shifting a manual tranny with out clutch depressed enough) I also haven't verified if 4wd works in the donor (The light comes on, but not tested.)
 
Yes, the donor is a 3spd auto and my rig is a 4spd auto.

The stock 85 came with 15x6's, so I swapped to i believe 16x8s or 16x7s (I don't remember now and the size isnt listed on my bill of sale). I had assumed the 81 was also smaller width wise...sounds like I am wrong?

I am shifting while in neutral. Also, in my rig when going from 4 Hi to 4 lo, there is a brief gear grinding noise during the shifting only (Similar sound to shifting a manual tranny with out clutch depressed enough) I also haven't verified if 4wd works in the donor (The light comes on, but not tested.)

Ok, the transfer case in the donor truck will have a 32-spline input shaft, while yours will have a 27-spline input. Otherwise they should be identical NP208 units (if stock). You can use them interchangeably if you swap input shafts.

The 8-lug rims should be 16", and you should be able to mount your tires on them without problem. Rim width isn't hugely critical. What is the tire size?

If you're unable to shift ranges while stopped and in neutral...I'd say there is a problem. But I sometimes have grinding in my ranges when shifting, if I'm not particularly careful to have zero moving speed. The range gears are unsynchronized, so speed must be exactly correct in order for them to mesh without grinding. If you're slightly rolling they will grind. If you're completely stopped (on the brakes) AND in neutral, they should not have a problem. Shifting from 2WD --> 4WD, OTOH, should be easy when you're stopped (but it can be a slow synchronizing wait if you're not stopped). With manual hubs locked in, you should be able to engage 4WD any time the axles are traveling the same speed (doesn't work when you're turning). My owner's manual says not to engage automatic hubs at speeds over 25MPH, so they have limitations that manual hubs do not. But they also engage automatically instead of waiting for you to get out and walk around the truck, so it's not all bad. ;)
 
So I am not going to write a long response just touch the high points. Your stock 16" rims on the 3/4 will work fine, I have yet to see a gov lock fail in a sf or ff 14 when I worked at the dealership. Anything can be broken but I felt with a lot of farmers and they can be hard on stuff. If it fails at some point I would go detroit but I have them in 2 of my trucks and I am used to there slightly different driving style. It should be an easy swap. I am guessing you have to reassemble the donor to at least moving so I would suggest you get a few things up front. For sure get a die that you can thread down the u bolt threads before attempting to remove the nuts. This will help you save the ubolts so when you put the halfton axles you aren't spending money on a vehicle headed to the salvage yard. I have cribbed many times with out a problem, just look 2 steps ahead so your placement does not interfere with the axle removal. Sounds simple, still I have done it wrong before. I would take the wheels off both vehicles and set the on the rotors/drums so the don't have to be so high causing the jack stands to be more tippy. Since the front calipers are the same I would remove them and wire them to the frame on each one so you don't have to worry if the fittings are different at the caliper. The rear hose removes from a steel line on the frame. Make sure you use line wrenches or you will be learning about flaring and replacing brake line. Finally unless inspection tells you different I would assume the new axle needs brakes, axle seals, lube change and the front bearings repacked.
 
I would buy a sway bar disconnect from ord because you live in Colorado. I have been on the interstate there doing 80+ in a water bed and it is a bet unnerving but not enough to use both hands or watch the road. I have been on lots of the trails around keystone and Breckenridge. It is a lot of fun but I am not sure my 4 month old would agree right now so I will most likely have to wait a few years to go back.
 
Update and a question:

Ok, I started the project today. First snag i ran into, I had to buy a female torx socket set. Second Snag, the E10 torx socket that worked for 3 bolts, did not work for the 4th. Had to then go buy an E12 torx socket. Drive shaft unbolted from the rear axle:



I Removed the nuts off the lower shock mount on the axle (My box wrench w/ cheater and electric impact drill could not brake one free) Ended up borrowing my buddy's air guns and compressor (I now know my next purchase.. please wifey pleaseeee!)

Now my question: How do I remove the bolts in the shock mount on the dif? They don't budge with an air gun. I tried to hammer it out. What am I doing wrong? I can spin them in place very slowly with a ratchet. :1zhelp: While trying to remove one, the shock snapped OFF at the upper shock mount on the undercarriage and woulda hit me had the exhaust not been blocking it's fall.

I've used a bunch of PB blaster on everything as well

 
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If the air gun isn't doing it you may try heating. I've heard 2 theories on that. On is heat the nut so that it expands. The other is to heat the bolt so that it expands and stretches the nut. I've had more luck /w the 2nd. Or, you can cut the bolt and replace.

Oh, and don't heat the shock too much.... contents under pressure.
 
The bolt is likely seized in the shock bushimg. Cut the bolt on the inside of the shock tab with a zip wheel and then you will press or burn the old bushing and bolt out. Pick up some new bushings and bolts and carry on with your day

For what it's worth I will use a 1/2" electric impact anyday over a air impact.
 
Ive had the bolts seize into the inner metal sleve and spin it inside the bushing. Also have had the bushing spin in the shock eyelet. either way its not worth the hassle to try and remove, grab the grinder and zip wheel and be done with it.
 
OK, So how much pressure am I suppose to use? I was taught to always let the tool do the work, but I've been using the metal cutting wheel the 8,500 RPM makita grinder came with and it doesnt look like I've made much of a dent (What I can barely see through the cut through bushing). Sparks are flying and im focusing on not damaging the shock mount.

I've only ever cut metal with an acetaline torch before.
 
I was really trying to finish for the k5 meet up in moab, but did not get her dialed in till today (1 Year and some change since I broke her, getting hitched and unemployed sure stalled the project)

I wanted to give an update:

I completed the swap! Front and rear!





Challenges I ran into:
Every bolt on the donor was seized. Fire became my friend. Now I have a giant breaker bar and several new tools.
I needed new rear UBolts because of the lift (blocks)
Front calipers seized she didn't brake well! .. So I just replaced both. I've bled the lines, but pedal still feels spongy (Friend told me next step is to take apart rear drum and hope it's not the master cylinder)
O'Riley staff are not to be trusted. Do your own research on parts. (I got to do the brake job twice!)
When I took her to an alignment shop, the tech told me to check the axle nuts when I get home. The passenger front axle nut was able to be hand spun. I tightened. (This reminds me how little I know of what I am doing)
I cross threaded the female threads on the rear diff pumpkin of one hole (I got the bolt out, but learned about tapping a new hole) Again, more tools.
I Lost the tiny bracket that keeps the drive shaft attached to the yoke of the rear dif and attempted to limp the donor out of my garage (If you don't have both brackets, the cap will come off the Ujoint and throw needle bearings all over your street)
If you over fill the rear dif, it will puke fluid after sitting for a few days.
Brake lines require their own damn wrench, again more tools.
Don't go crazy with the paint (I painted the brake bleeder nipple thing and had to clean forever)
The rightstuff gasketmaker in a nozzle can is great.


Bought Donor for $400.00. (Salvaged optima battery, spare drive shaft, some of the external plastic crap (I expect to break some day) Sweet tube bumper)
Sold hacked up donor with axles barely thrown back in for ($300.00) I forgot to swap out the expensive black pro comp lug nuts for the cheap shitty ones that the donor came with.
Sold Wheels/Tires for ($300.00)
New calipers and pads set me back $150.00
I spent about $250.00 in new tools
New Wheels + Tire removal + mount and balance + Lug nuts was $916.00 (If I can move the 6x6.5 pro comp wheels for about 500, and the OEM bumper for like 30-50 bucks ill feel pretty good about this)

THANK YOU FOR ALL THE ASSISTANCE!!!!
 
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