Diff rebuild recommendations

dndj

Boost!
Apr 13, 2019
135
1
18
Oregon
Hey folks in the PNW, looking for recommendations on who would be good to rebuild the rear end of my 03 LB7 in the Portland, OR area. The ol' G80 gov lock decided it wanted to stay locked for good today and not release with about 140k on the clock.

I have used Six States in the in the distant past and they did a great job. Are they still pretty much the go-to guys in PDX? I also had a very bad experience with Paden Drivetrain 15 years ago and won't be going back there any time soon.

Also consensus seems to be to not bother rebuilding the G80, looking at Truetrac as a stronger alternative. Not really interested in the Grizzly or Detroit Locker, truck is a DD and I want really good street manners.

Thanks
 

Bdsankey

Vendor
Vendor/Sponsor
Feb 1, 2018
1,965
30
48
Neenah, Wisconsin
Hey folks in the PNW, looking for recommendations on who would be good to rebuild the rear end of my 03 LB7 in the Portland, OR area. The ol' G80 gov lock decided it wanted to stay locked for good today and not release with about 140k on the clock.

I have used Six States in the in the distant past and they did a great job. Are they still pretty much the go-to guys in PDX? I also had a very bad experience with Paden Drivetrain 15 years ago and won't be going back there any time soon.

Also consensus seems to be to not bother rebuilding the G80, looking at Truetrac as a stronger alternative. Not really interested in the Grizzly or Detroit Locker, truck is a DD and I want really good street manners.

Thanks
I cannot comment on a shop, but I can comment on the components. I would personally go with a Truetrac, they are much improved over stock and will actually act like a LSD. They are 100% worth the money. The G80, even if you rebuild it or replace it, will do this again. If the truck is relatively mild I wouldn't worry about upgrading axle shafts or anything else that hasn't failed. Depending what happened the ring and pinion may still be good as long as they haven't seen large metal pieces.
 

c5fourj

Occasionally moving quick
Dec 20, 2014
301
0
16
Brighton, CO
Just had a truetrac thrown in my truck this summer, as my diff quit locking. Great street manners and I never look back. I wouldn't hesitate to get it.
 

dndj

Boost!
Apr 13, 2019
135
1
18
Oregon
Thanks guys. Really appreciate it. Just ordered up an Eaton/Detroit TrueTrac and have an appt set up at Six States to get it installed on Monday. They also recommended I put all new bearings in since i'm getting up there in mileage, so I'm going to go ahead and have that done too at the same time.

In case others are looking, this is the unit. https://www.eaton.com/us/en-us/skuPage.915A568.html
 

DAVe3283

Heavy & Slow
Sep 3, 2009
3,333
14
38
33
Boise, ID, USA
ReaperLegion.net
I have a TrueTrac in my '03 for a couple years now and love it. They allow more slip than the G80 in extreme situations (one tire on ice, one on pavement, etc.), but it will transfer the power after a bit and get you moving. On normal roads it's fantastic, puts power down really well and never hits hard or destabilizes the truck. And unlike the G80, it will survive 700+ HP more than once.
 

dndj

Boost!
Apr 13, 2019
135
1
18
Oregon
Well I had the guys at Six States swap in a TrueTrac today. Kind of a beast, weighs around 65-70 lbs without the ring gear installed. Thanks for the recommendations, I've heard nothing but good things about the unit.

Just for fun I took some pictures of the G80 gov-lock carnage (Grenade-80 or gov-bomb , your choice ;)), figured I would at least get a little entertainment added in for my $$$. Normally in a G80, there is a spur gear that sits behind the drivers side spider gear which drives the flyweights. This gear also has machined ramps which engage with the ramps on the back side of the spider gear and force the clutches to lock up when engaged. Video here if you want to learn more https://www.youtube.com/watch?v=ftyJvIO0DZ8 The spur gear was basically shattered and wedged between the spider gear and clutch pack leading to the G80 being stuck in the lock applied position. On the opposite side, the flyweights and little pinion gear shaft which engages the spur gear appeared to be OK.

Also drivers side carrier bearing was wasted. Passenger side looked OK. I didn't check the pinion bearings, but all were replaced. Ring/pinion gears appeared to be fine so they were reused.
 

Attachments

NC-smokinlmm

<<<Future tuna killer
May 29, 2011
4,599
0
36
At Da Beach
My g80 had a crack in the carrier all the way across that was a 1/2" wide in a spot. It was still working just dragging drivers side on right turns.:rofl:
 

dndj

Boost!
Apr 13, 2019
135
1
18
Oregon
Wanted to report back - Six States in Portland, OR did a great job installing the True Trac, setup must be right because the rear end is completely silent, original ring/pinion were in good shape and reused.

Good Lord this thing is effective - wet or damp roads = instant sideways with a bit too much go pedal on tune 3. :eek: :D Wish I would have made the upgrade sooner. The G80 kicks out at 20-25mph by design so it had limited effectivness anyway.

Thanks for the recommendations.
 

dndj

Boost!
Apr 13, 2019
135
1
18
Oregon
Love mine. I’ve had it for about 5 years.

That ain’t carnage- lemme upload a few pics of my buddy’s 1500 rear. Ouchie. Lol

35” tires, lift kit, woo-tan-Wind-warrior, and an angry foot.
:rofl: Wow. That's nasty. :eek: Amazing that GM has shipped these for so long with the bad reputation they've earned.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
17,242
49
48
Phoenix Az
They work well for their intended purpose and was one of the only mfg that offered the closest thing to a locker for a long time in a truck. Till the late 2000s when ford started putting e lockers in

They just don’t like abuse. Coming around the corner and standing on the throttle, causing one tire to spin fast/hard and then the locker hitting with all that built up momentum is going to hurt things after a while. Add bigger tires or more power and it just makes it worse. When clutches start to wear, you gain more “dwell” as well which just lets the tire spin more/create more inertia.

I agree through. With what’s out there for options, it’s time for gm to update the 40 year old tech
 

KyleC4

Tech
Dec 30, 2016
339
7
18
Bay Area
They have the tech. They just need to get a supplier on board with a design change to be implemented. But I also understand how that’ll probably increase the cost of mfg per unit and that doesn’t sit well with everyone up top. Cause can these new vehicles get any more expensive? 2019 Premier Tahoe with all the fixens’ had a sticker on it for $90k......ouch
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)