Best wishes to all involved.

 

So is then should have clutch packs? Also is it supposed to have the locking cams? When the tires were spinning I never heard any "clunk" that they supposedly make when engaging. I looked underneath and it does have the enlarged axle shafts near the diff and the little triangle points on each side of the bottom so at least from the outside it seems to be the correct axle.

 

I'm here to help. Sorry for the delay. I was checking something else. Yes. the the g80 has friction discs. Friction modifiers are not necessary according to GM and eaton. I don't treat them as if they had clutch packs. They were designed for low traction not burning tires on the pavement. They are rebuildable but for a couple hundred more a much stronger posi carrier can be bought.

 

OK I have opened the rear diff. pan. It has the rotating cams and looks like also clutches. Is there a bench test for the rotating cams? I'd like to check that out before I pull axles to replace clutches. Can you guys hook me up with a link on this subject to help save search time. Also there are some etched #s on the ring gear and painted #s. Can you guys decipher these? I included a few photos for reference...

The expanding tangs.

Clutches on right side.

Left side.

Are there clutches on this side? Left side.

etched #

Painted # Same # is also on pinion.

More etched #s.

Bearing cap code?

 

I'm betting it's just fine and that your expecting it to lock while sitting in park is invalid. At least I've never seen one that does. Better leave it alone.

Locking Differential Description and Operation
The locking differential consists of the following components:
Differential Carrier

• Locking Differential Spider
• 2 Clutch Disc Sets
• Locking Differential Side Gear
• Locking Differential Clutch Disc Guide
• Differential Side Gear Shim
• Locking Differential Governor
• Latching Bracket
• Cam Plate The locking differential allows for normal differential function as indicated in the standard rear axle description. Additionally, the locking differential uses multi-disc clutch packs and a speed sensitive engagement mechanism that locks both wheels together if one wheel spins excessively during slow vehicle operation. Under light loads, the clutch plates alone tend to lock the axle shafts to the differential case, and therefore locking to each other. This is due primarily to the gear separating the load developed on the right clutch pack. This induced clutch torque capacity resists motion between the side gear and the axle differential case. The differential allows the wheels to turn at different speeds while the axle shafts continue to transmit the driving force. Heavier throttle application will cause an axle speed difference. This action starts the full-lock feature of the unit. You can accomplish full-lock through the use of a heavyweight governor mechanism, a cam system and a multi-disc pack. The flyweights on the governor mechanism move outward in order to engage a latching bracket whenever the wheel-to-wheel speed varies by approximately 100 RPM or more. This action retards a cam, which, in turn, compresses the multi-disc clutch packs, locking both of the side gears to the case. The 100 RPM wheel-to-wheel speed allows for cornering with the differential lockup. At vehicle speeds above approximately 32 km/h (20 mph) , the latching bracket overcomes a spring preload and swings away from the flyweights. At this vehicle speed or greater, the differential is designed not to lock since added traction is generally not needed. The axle parts of the vehicles equipped with the locking differential are interchangeable with those equipped with the conventional differential, except for the case assembly.

 

[QUOTE=LesMyer;698633]I'm betting it's just fine and that your expecting it to lock while sitting in park is invalid. At least I've never seen one that does. Better leave it alone.

The problem is that it really does not work. I had the vehicle on a hillside in my driveway, one front wheel was just about off the ground and one rear wheel was just about off the ground. The front tire spun as expected. The rear tire also spun and nothing locked-engaged-clunked-hic-cupped or anything. Acted completely like and open differential. Spun the tires multiple times at different RPMs and still nadda. So, trying to see if there is a bench test for the cam mechanism and if it can be removed w/o taking out the whole works. If that works then I will assume it needs clutches. Trying to figure all this out without having to take it in to a 4wd shop and give up my left arm.

Also, I am hearing that there are better systems if I need to go through all this trouble than to rebuild the G80 for not a whole lot more $. So curious about that also.

Thanks.

 

So continuing with this saga....

I opened the rear cover plate. The spring activated "locking" device works and catches both in forward and reverse. All the gears look good and the oil clean. No metal chunks or residue. However the single wheel continues to spin when jacked in the air and NO power is transferred to the opposite wheel. So my assumption is I need to replace the clutch packs. I have heard it is tough to get the carrier apart to do this. Is it worth trying to fix if it is just the clutch packs. I have read much about replacing the G80 with stronger stuff. If I choose to do this then I realize I will have to swap the ring gear to the new carrier. Is it that simple if I get a replacement Eaton "Posi" or do I have to set the ring and pinion gears all over again. I'm looking to keep this as simple as possible without taking this to a 4WD shop

 

I've never even heard of anybody wearing out the clutches on a G80 before this. They're kind of an on/off thing, so there's not much slippage. That's why they tend to explode.

Anyway, if you just change the carrier and reuse your ring gear, you only have to set the carrier bearing preload and backlash. Both are pretty easy. Pinion depth is the hardest part, but you don't have to worry about that. Measure the backlash before you take it apart, and set it to the same value.

 

[QUOTE=Tom A;698727]I've never even heard of anybody wearing out the clutches on a G80 before this. They're kind of an on/off thing, so there's not much slippage. That's why they tend to explode.

I guess they are an "off" thing right now. I heard punching out the pins for the G80 spring clutch engagement device is the toughest part...

I might give this a try and if I screw it up then i will just change the carrier to something different.

 

[QUOTE=nomoresubies;698728]My G80 experience is limited to taking them out and throwing them away, so I can't really help you. Good luck, though, and let us know how it goes.