What is this bolt?

[PlayingWithTBI]

What's this "Differential Housing Spreader" they discuss in the 1998 FSM?

IIRC that's used to remove/install the carrier without having to mess with the spacing adjustment. When setting your backlash there needs to be no side to side movement between the bearings.

 

[Erik the Awful]

No harm in sending it and seeing what happens, just expect noise.

I'd put gear oil in it and send it. If there aren't any crunchy noises I wouldn't even bother changing out the gear oil until I had 30k on it. Corrosion on the ring gear? If it's on the wear part of the gear it will self-solve. If it's not, who cares? The one thing I would do is attack the rust with a wire brush and clean it off. No sense in getting rust particles in your gear oil unnecessarily.

When I was in Nissan school a buddy picked up a Datsun 720 King Cab pickup for $300 because it had a blown head gasket and no 5th gear. We had half a dozen of the 5-speed transmissions sitting on the shelf in the shop, so one afternoon he and I pulled the transmission and blew it apart along with two other transmissions. Between the three we assembled the best parts into the transmission, but the 5th gear was a mis-matched set. It whined for about a month, then quieted down and became a solid daily driver.

 

[Schurkey]

After putting the axles back in with seals and it bolted together, I ripped it all apart again. Got as far as taking the carrier out.

I hope you checked the backlash before screwing with the shims 'n' adjuster nut. When it goes together, it's going to want to be at the SAME backlash while also having proper bearing preload.

If you're going to put a heap of miles on this thing, sure, a new ring 'n' pinion is a good idea. Setting pinion depth is the hard part. Getting backlash right isn't so bad. If you're not replacing the ring 'n' pinion gears, for ****'s sake do not screw with the pinion.

If this isn't going to be a high-mileage vehicle, I'd have thrown two extra magnets into the housing and looked-in on it after five thousand miles. (Or earlier, if it's actually noisy.) From a certain perspective, the ring gear is already ruined; and the pinion is matched to it. As long as you don't screw-up any of the other bits 'n' pieces, you've got little to lose by putting it together and seeing what happens.

 

[someotherguy]

I just saw an episode of All Girls Garage do a ring and pinion swap, they made it look easier than when I’ve done them. they had all the right tools too

None of us got to drive the vehicle afterwards and hear how the thing sounded, though, right?

My thoughts - and I'm happy to be corrected - carefully wire wheel the rust off the teeth, clean the hell out of everything, fill it up and change fluid frequently while keeping a close eye on the magnet. If it DOES start coming apart, yeah, you're gonna start wiping out bearings and causing yourself more grief and expense.

Richard

 

[BigReb95]

The truck is my daily driver, I'm borrowing a family members car until its done, which is taking longer than expected due to working.

I guess on the 14 bolts, there's an adjustment shim on the right side, then stationary shim on the left. I counted the turns on the adjustment side so when I put it back together it will be in the exact same spot. Now I gotta order the stuff. Just don't like set backs, I miss driving big red.

 

[BigReb95]

My God I'm gonna be into this thing another 500 bucks between the gear kit and bearing kit. I'm about to have a stoke. So much for a "junkyard find."

 

[RichLo]

You got a free Detroit locker out of the deal

 

[BigReb95]

That is very true. That reminds me, if any of you had experience with lockers, are they pretty dependable? I have 6 inch lift and 35s so it would definitely be nice.

 

[RichLo]

I have a Detroit in my 14bFF Dually. Love it! It only pops out and ratchets under no load in gas station parking lots after the fluid has warmed up. Once I touch the throttle it locks up and stays there.

 

[Schurkey]

I guess on the 14 bolts, there's an adjustment shim on the right side, then stationary shim on the left. I counted the turns on the adjustment side so when I put it back together it will be in the exact same spot. Now I gotta order the stuff.

"Counting turns" on the adjuster nut means NOTHING if you change the bearings, or the gears, or use a different differential case.

IF (big IF) you were going to re-use the bearings and gears you have now (I would, if it were me) then MAYBE counting turns of the adjusting nut is sufficient if using the same shim(s) on the left side. I would have checked the backlash directly. That's the proper way.

But it sounds like you're changing the ring 'n' pinion gears; which means you'll be playing with pinion depth, bearing preload, gear patterns, and setting backlash all from scratch. Good luck. That's a big and involved job.

My God I'm gonna be into this thing another 500 bucks between the gear kit and bearing kit. I'm about to have a stoke. So much for a "junkyard find."

Do you have the dial indicator and stand, and the low-inch-pound torque wrench for measuring bearing preload? Do you understand how to set pinion depth? How about the ginormous 1/2 or 3/4 inch ratchet or breaker-bar and cheater pipe for deforming the crush collar?