Upgrade underway!

[rascole]

Quickly turns into a major overhaul. Good luck.

 

[RamRod]

Wanna do my front diff now that you have had some practice!

Sent from my SM-G935W8 using Tapatalk

 

[alrock]

Wanna do my front diff now that you have had some practice!

Sent from my SM-G935W8 using Tapatalk

Still gotta finish the rear! Many thanks to CJ and Reloader for helping me come up with a parts list. Here's the rear-end rebuild list:
Eaton Gear Kit 29296-00S $130
Eaton Locking Mechanism Kit (includes ramp) 29305-00S $265
Ring and Pinion Yukon 24161 $218
Motive Gear R10RLMK Master Bearing Kit with Koyo Bearings $100
GM 12479031 Wheel Bearing, Rear x2, $45 each
GM 12471686 Axle Shaft Seal, Rear, $13 each
Heavy duty diff cover, $100

 

[H32NV]

Went back an hour before the expo was over and offered them $40 for the master kit, and they accepted. They've got 1 more master kit available, if anyone wants me to grab it for them. They've also got G2 GM 7.5 Ring and 4.56 gear discounted from $224 to $120. Might be able to get it for $60.

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I need front diff parts for a 4.56. ring and pinion. Is this opportunity gone? - Rob

 

[DFW Spartan]

I need front diff parts for a 4.56. ring and pinion. Is this opportunity gone? - Rob

It is for Dallas. It was at the 4WheelParts Truck and Jeep Expo. They had a clearance section in back. A lot of jeep stuff, which moved pretty quickly. Some selection of GM parts. They were more motivated to cut a deal on what was left the 2nd day vs. hauling it back to the various stores.

Not sure if you have a 4WHEELPARTS store in your area, but they had a list of cities around the country they were doing the expo. Check it out if you're able. It was free.

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[alrock]

Alright, the H3 is up and running again with many thanks to Reloader.

Today, the rear diff was completely rebuilt. New ring & pinion, rebuilt locker, new wheel bearings, new seals, etc. Also turned the rear rotors. Frustratingly, the front rotors (AC Delco) also have a warp with only 10,000 miles on them. And a new passenger side wheel bearing to match the new driver's side wheel bearing.

Here's a couple more shots of the locker parts. This locker has been in there for 6 years. The pins are not too bad but were due for replacement. The ramp was suprisingly not worn down, though that missing piece is significant. I've been careful about engaging the locker with the wheels stopped, rolling forward a couple of feet before any obstacle. I think that's helped prolong the life of these two parts.

All in, about 18 hours of work over two weekends.

We'll drain the diffs in about 500 miles, refill and put on the new cover.

 

[mdocod]

I have a feeling this thread is going to be a reference for many of us.

Thanks for keeping track and sharing alrock!

 

[Schwarttzy]

 

[3Hummers]

Alex, you are going to have a new truck before long.

 

[alrock]

Got about 600 miles on the truck since we did the diff swaps/rebuilds, so we pulled the covers today and inspected the gears. Thankfully, no shavings! Gear patterns were right on target on both the power and coast side of the ring gear.

Filled both diffs with Lucas Synthetic 75W-90. Found out I could get it online and delivered to my home through O'Reilly cheaper than they sell their house brand in the stores at just under $12/quart. Since I was using this new Heavy Duty Diff Cover from Chassis Unlimited (recommended by both 4speed and Reloader) I figured it might be a slightly higher capacity and it did take a bit more - it was about 4.5 qts to fill both, whereas factory fill is about 4 qts.

The cover comes bare but I ground off the logo, primered it and applied Rustoleum Hammered Metal Black. Note that the welds interfere with the bolts so some welds have to be ground down (or the bolt head flange ground) to get it to sit properly.

I fudged the RTV on the diff cover so we had to slather some on the outside. I wasn't up for redoing it today since it was about 102 outside when we finished and double that in humidity.

 

[4speedfunk]

Next time ditch the RTV and reuse the stock gasket. They seal up great and leave no mess (they’re reusable). That’s why they cost $25. Lube Lockers are the same basic thing, a few bucks cheaper...
https://www.summitracing.com/parts/...1YILWFhJyz_eYGhLeObFRvdCvGVFSuzBoCVyQQAvD_BwE

 

[720H]

Since I'm new here one of those guys replying to old threads. alrock very informative thread. Question, have a pic where you mounted the switch and have a safety for accidentally bumping on or tied into the rear locker

 

[alrock]

My lockers are the two buttons with blue lights below the fan dial. Left is rear, right is front. I put the one I'd use the most closer to me. I don't have any additional safety switches as these are not areas that I'm prone to bumping into those switches. These are generic aftermarket switches.

 

[720H]

Thanks, that a clean look

 

[jakesz28]

I am in process of ordering most of the same parts. I ordered the two AAM bearing kits CJ recommended. Hopefully they are the correct carrier bearings for the locker. Picking up a donor axle next week so this can be built and on the bench before I pull my dif.

Hard to believe I got a 105,000 miles on the factory dif and CV's. Buying another set of AC Delco CV's seems the way to go.

 

[jakesz28]

Did the install work today for new cast iron front locker. Reloader was able to assemble the CI diff this week using the new parts plus parts scavenged off of a spare diff in the garage.

We reused:

• Diff cover
• Axle tube
• Yoke
• Passenger's side diff mount plate as it was from PCF. I upgraded the driver's side at this time. (Only passenger side had been replaced as it was the prototype for the upgrades that he offers now).

New parts:

• Cast Iron differential housing 25831502 ~$400
• Eaton locker, OEM 25800300 ~$540
• Bearing kit, USA Gear. USA Standard Gear (ZK GM7.5-A) Master Overhaul Kit for GM 7.5" Differential $60 (incorrect pinion bearings included. Look for a 7.625 IFS bearing kit if you want kit with correct pinion bearings)
• Outer pinion bearing 9417784 $39
• Inner pinion bearing 22510042 $35
• Pinion bearing crush sleeve $13 (included in USA Gear kit)
• Breather connector 15876530 $8
• Drain plug (can be reused from alum diff) 92230583 $12
• Front differential pinion seal 12479267 $13
• Yukon ring and pinion, (YG GM7.5-456) High Performance Ring and Pinion Gear Set for GM 7.5" Differential $261
• Bracket 25933550 $3
• Side axle bearings

Since we were doing this work, it gave us easy access to the motor mounts. This is mount #5 on the passenger side, #3 on the driver's side. The driver's one didn't need it yet, and the passenger side was just a few miles away from failing.



I also put in the PCF diff support, as mentioned



We drained the old diff and found good shavings on it. After we pulled the diff, we found that the ring gear was badly damaged on three teeth.


Also found out that the driver's side wheel bearing was shot. The passenger one isn't far behind. These are the original bearings with 174,000 miles on them
[video=youtube_share;gXhClgMJXYw]https://youtu.be/gXhClgMJXYw[/video]

We decided to do the rear brake pads too but realized the rear wheels were not spinning smoothly, so we drained the oil from the diff. The drain plugs should not look like this. This appeared to have "normal" locker shavings but also more than that.


We removed the rear diff cover and found this chunk underneath about the size of a large molar


Here's the side gears that are missing teeth AND broken into two pieces




There's a dent in the cover that suggests that pieces tried to evacuate themselves through the cover at some point.


So, now it's time to completely rebuild the rear end: new ring and pinion, carrier bearings, entire locker assembly, axle seals, etc. It's undriveable until then.

Alex, the bracket to stop the locker from rotating has to be purchased separately, 25933550?