71 C-10 12 bolt rear end rebuild parts questions

[bmxbang]

Alright guys i'm getting ready to rebuild my rear end on the C-10 and I have a few questions. The truck is not a daily driver and i'm looking for a happy medium in performance and drivability at all speeds.

Current set up
Drive train = 5.3l LS engine NA
Transmission = 4l60e
Current rear end gears = 3.07
Stock 12 bolt chevy rear end

Planed set up for rear end
-Rebuild current 12 bolt Rear (PN = ?)
-Yukon Dura Grip Positraction (PN = YDGGM12T-4-30-1)
-Swap out gears to 3.73 (PN = ?)

So my question are

Thoughts on this set up?
Best brand rebuild kit to purchase?
Best brand gears to purchase?

Im not trying to go broke on this but I also don't want to have redo things a second time. Any insight is appreciated thanks guys!

[Ironangel]

The only problem with Yukon is none of their parts are made here in the US anymore. The actual "Eaton" Posi's are getting hard to find and when you do find one you can expect to pay upwards of $600 for it. I run an Eaton 556-010 with Yukon 3:73 gears (because nobody makes US made gears anymore) in my daily driver and an original factory Eaton truck Posi in my drag truck with 4:56 Yukon gears...Yukon uses foundries from all over the world and laps their gear sets here in the US. USA Standard Gear is Yukon's sub-optimal line of products that I would stay away from. All the other so called gear manufacturers use over seas foundries, Richmond, Motive, etc. are made off shore. Yukon's name brand line is held to a higher standard supposedly so take that for what it's worth. I've been pounding away at Yukon gears in both trucks for years now and can only say they haven't broke yet but the 3:73 gear set is making noise after 6 years and roughly 50,000 hard towing miles. You have the right idea with the old school Posi and 3:73 gear combo. If you can afford the Eaton over the Yukon, get it! Do your research and you should be able to find an NOS GM 12-bolt truck 3:73 gear set. Until then, the Yukon gear set is as good as gets...Here's an Eaton posi for as cheap as your going to find them today and don't be fooled by the Chinese copy's! https://www.quickperformance.com/GM-...0_p_20456.html Timken over Koyo just because they're US made, mostly...

[Trucknut57]

I just installed an Eaton Detroit Truetrac in my 12 bolt, I thought this was a better option to a regular posi unit, since it doesn't require an oil additive and the clutches won't wear out. It was stamped with made in Taiwan but what isn't these days. But I did reuse my original ring and pinion gears.

https://www.summitracing.com/parts/dtl-913a315/

Also purchased a Richmond rebuild kit and it has everything I needed to install the new carrier

https://www.summitracing.com/parts/rmg-8310181/

And in a couple of bearings and seals and it's rebuilt

https://www.summitracing.com/parts/yga-10001/

[mongocanfly]

Yeah I went Yukon gears and Yukon setup kit with the truck rear diff...
Your wanting 3.73s...what is your rear tire size?

[bmxbang]

Originally Posted by Ironangel

The only problem with Yukon is none of their parts are made here in the US anymore. The actual "Eaton" Posi's are getting hard to find and when you do find one you can expect to pay upwards of $600 for it. I run an Eaton 556-010 with Yukon 3:73 gears (because nobody makes US made gears anymore) in my daily driver and an original factory Eaton truck Posi in my drag truck with 4:56 Yukon gears...Yukon uses foundries from all over the world and laps their gear sets here in the US. USA Standard Gear is Yukon's sub-optimal line of products that I would stay away from. All the other so called gear manufacturers use over seas foundries, Richmond, Motive, etc. are made off shore. Yukon's name brand line is held to a higher standard supposedly so take that for what it's worth. I've been pounding away at Yukon gears in both trucks for years now and can only say they haven't broke yet but the 3:73 gear set is making noise after 6 years and roughly 50,000 hard towing miles. You have the right idea with the old school Posi and 3:73 gear combo. If you can afford the Eaton over the Yukon, get it! Do your research and you should be able to find an NOS GM 12-bolt truck 3:73 gear set. Until then, the Yukon gear set is as good as gets...Here's an Eaton posi for as cheap as your going to find them today and don't be fooled by the Chinese copy's! https://www.quickperformance.com/GM-...0_p_20456.html Timken over Koyo just because they're US made, mostly...

Ironangel Thanks! I appreciate the real world input on the Yukon gears! I had strayed away from eaton just because the few I had seen where up there in price but it may be worth it to jump up to them, thanks for the link

Originally Posted by Trucknut57

I just installed an Eaton Detroit Truetrac in my 12 bolt, I thought this was a better option to a regular posi unit, since it doesn't require an oil additive and the clutches won't wear out. It was stamped with made in Taiwan but what isn't these days. But I did reuse my original ring and pinion gears.

https://www.summitracing.com/parts/dtl-913a315/

Also purchased a Richmond rebuild kit and it has everything I needed to install the new carrier

https://www.summitracing.com/parts/rmg-8310181/

And in a couple of bearings and seals and it's rebuilt

https://www.summitracing.com/parts/yga-10001/

How have you liked the trueurac? Im honestly new to the rear differential world so i'm open for opinions? thanks for the links! The whole reason i'm doing this is because I had an axle seal break loose so I figured heck why not just replace everything!

[bmxbang]

Originally Posted by mongocanfly

Yeah I went Yukon gears and Yukon setup kit with the truck track diff...
Your wanting 3.73s...what is your rear tire size?

how have you liked it? how many miles have you been able to put on it since you swiped out the rear with the new gears?

My current tires size is 235/75 on some 15inch steelies but they won't be on it long term.

[mongocanfly]

My truck is still in build stage....I have a buddy with the same setup and he loves it though...hes been running his several yrs

With 3.73s , .7 od, 29.9 in tire you'll be turning 1907 rpm at 65mph..
With the same setup,but with your 3.07s ,you'll be turning 1570 rpm at 65mph...

The LS swaps I've done it seems like the LS ,and me ,like around 2000rpm at 65mph...but that just me
1907rpm isnt bad...but if you change tire od size it will effect it

[LS short box]

I've used the Tru-Trac in a couple of swaps. They worked very well. In my current C10 LS swap I used 4:10's. I'm running 285/40-20 in the rear so a fairly tall tire. My combo works well. I used Motive Gear gears and they are very quiet.

[Trucknut57]

I haven't had a chance to try it out, unfortunately some medical problems came up and have been sidelined for awhile.

But everything I have read about the Trutrac has been good. Plus pricing is close with all the other ones out there.

[3767]

U may want to nail down your tire size first. The original tire height was 27 in. Anything more in height will change the rear gear, no matter what you get. A popular size going is 275/40/20. This is about 29 inches. So... now a 3.73 is more a 3.55. If u plan on running a tall tire then go lower with the gear just to help get you back to the right rpm. Knowing what size u will b moving to can help u make a better decision. I have an eaton posi and Yukon gears n mine. Been there for 15 yrs. Gears still look good along with posi unit. With that tranny u have, a 3.73 works well. The truTrac is a good unit as well. They engage a little firmer by design.

[SmirchIs#1]

I agree with Ironangel & I can tell from his response that he does rears.I bought a Yukon unit when they came out, to gut it and compare internals & dimensions to an OE Eaton.Internals would be interchangeable.The Yukon is a reverse engineered COPY of the Quality Eaton.However the Yukon posi case is full of stress risers and lacks a whole 1/8" of material where the bearing hub radiuses into the main case.I have never bought another and still have that POS.I have a dozen of orig.12 bolt Eaton truck series III posi units.In severe use applications,these units would hair line crack in the lower left corner of both windows(ok for normal use).Thanks to TOM from Tom's differentials in Idaho,who unfortunately is no longer with us,The new Eaton truck posi units have a much beefier case to rectify that problem.I have some very nice used OEM gear sets.Tom's wife and family are still operating & as of my last order,I'm still getting all Timken bearings.Tom was the biggest buyer & supplier of Eaton posi units in the world. Eaton respected his opinion.If you want more info feel free to call Dennis 518-528-2646