Rear Diff Problem

Glaxtx · October 4, 2004

My brother got a used '03 2500HD Ext Cab 6.0 back in June. He's got about 50k miles on it now, and is concerned about the rear diff. It has the locking differential and has not had problems until recently, when it feels and sounds as if it's locked all the time. You notice it mainly at lower speeds when cornering, the wheels turn together and you can hear the tires squealing. We're wondering if this is a common problem, as I haven't read much about it here. Hopefully someone may have gone through this, or knows what he can look at to fix it. Thanks for helping a newbie!

Matt

Cool Zr2 · October 4, 2004

Ive heard of the G-80 being stuck, it took a good range slam to pop it out. (F to R)

gunslinger45 · October 5, 2004

I have a 2003 Avalanche 2500 with the G80 in the rear and I had similar problems after only a few thousand miles. Before "slamming" anything I would ask if you have ever serviced the rear differential? I drained my fluid, and added new synthetic stuff as well as a special additive for limited slip differentials. I have had no problems since changing the fluid and adding the special additive. I will also say that when I changed the fluid in the diff, it was not completely full which could have been leading to lubrication issues since the G80 is essentially a clutch system. Anwyay, start with simple solutions and then progress before taking it to the stealer. Best of luck.

Trev

TimTim · October 5, 2004

I have put 500 miles on the my truck since buying it, and one of my 1st thoughts were "this thing is going to eat tires!" There are a few uphill sharp curves on my way home from work and I can hear the inside tire digging in. If you can coast around the corners I think you will save some tread?

I'm interested to see how it does in the snow? I loved to go out and play on snowy roads in my K20 std cab...somehow I don't think the CC/LB will be as easy to throw into a corner LOL. My guess is it will be a handfull.

whitesnake01 · October 5, 2004

Has he ever had it serviced? If it was mine, I would have serviced it 3 times by now (once just after purchase at 500+500mi, and then at every 25K).

TimTim · October 5, 2004

Has he ever had it serviced? If it was mine, I would have serviced it 3 times by now (once just after purchase at 500+500mi, and then at every 25K).

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Mine has been serviced, and by no means is the rear locking but I can notice a difference in road/tire noise while accelerating around a corner.

I have never thought it was something out of the ordinary? Its not like driving something with a "spool" in it. Maybe I should have mine looked at also?

vhato · October 5, 2004

Eaton's Locker (G80) features a carbon fiber clutch pack that engages before the counter weight engages the Governing "Locking" rod.

It is not uncommon for these differentials to "shutter" during a slow turn when the carbon fiber discs are attempting to slip.

These clutch discs are present so the transition to full 50/50 lock is not felt by the driver. Anyone with a Detroit "Locker" knows what I am talking about. It is rough.

Nothing is wrong, it is just letting you know it is there.

rascal · October 6, 2004

Eaton's Locker (G80) features a carbon fiber clutch pack that engages before the counter weight engages the Governing "Locking" rod.
It is not uncommon for these differentials to "shutter" during a slow turn when the carbon fiber discs are attempting to slip.

These clutch discs are present so the transition to full 50/50 lock is not felt by the driver. Anyone with a Detroit "Locker" knows what I am talking about. It is rough.

Nothing is wrong, it is just letting you know it is there.

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does that mean they act like a limited slip, then lock into a locker? was wandering who made the g80 anyway.

bigdogs · October 6, 2004

I had both a Detroit Locker in an old Blazer and lockers in my Polaris Sportsman and they made a lot more noise than this G80 does on turns.

vhato · October 6, 2004

I had both a Detroit Locker in an old Blazer and lockers in my Polaris Sportsman and they made a lot more noise than this G80 does on turns.

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Exactly!!!! Thanks for the backup.

Rascal,

Yes it starts out as an LSD then becomes a True Locker when the difference between both axle shafts exceeds 128 RPM.

rascal · October 6, 2004

I had both a Detroit Locker in an old Blazer and lockers in my Polaris Sportsman and they made a lot more noise than this G80 does on turns.

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Exactly!!!! Thanks for the backup.

Rascal,

Yes it starts out as an LSD then becomes a True Locker when the difference between both axle shafts exceeds 128 RPM.

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thank you.

Scyry · October 6, 2004

As for how the G80 does in the snow, I have it and rarely have to use 4WD. Only have to use it if I was dumb and parked on a bad hill or if it is deep snow (+6") As for eating tires, I have around 45,000+ on mine and they are not quite ready to be replaced. I rotate them every oil change though and check the pressure every time I fuel up, Colorado is hell on tire pressure

builderpaul · October 6, 2004

was wandering who made the g80 anyway.

Eaton makes these.

vhato · October 7, 2004

Here is a link all about the G80

http://www.automotive.eaton.com/product/tr...ockingdiff.html

bigdogs · October 7, 2004

Exactly!!!! Thanks for the backup.

Once you hear a locker going around a corner you don't soon forget that sound. My Blazer even had a locker (Power Lok) in the Dana 60 up front so it made even more noise on corners, altho the Sportsman does quite a bit of clicking in turns from the rear end..