AAM11.5 Yukon Helical LSD- 2016 LML

16LML

New member
Oct 6, 2019
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I believe I originally posted this in the wrong section, so I’m reposting here:

What is the difference between the Yukon Helical LSD (PN: YP PC11.5-HELIC; MSRP $2050.89) and an AAM 11.5” Helical Gear TracRite LSD (PN: 40099548; ~$800)? Many of the stock photos listed online for these two diffs are identical. Is Yukon selling a rebranded AAM part for $2.5x the cost, or is the Yukon diff an improved version of the AAM part? If the Yukon LSD has been improved, in what ways?

Finally, how do either of these compare to the Eaton Trutrac?

Searching various forums I’ve found extensive (and often conflicting) information regarding the TruTrac/Yukon Grizzly & Detroit automatic lockers, but essentially no information about the Yukon YP PC11.5-HELIC.

Initially I had planned to buy a Yukon Grizzly auto locker for use in a pretty heavily modified 2016 TT LML, but after some research it would seem this might not be a great choice as the truck spends a lot of time on the road. The truck came with an open diff- I’m looking for straight line & cornering traction.. mainly on road and occasionally off.

Thanks in advance,
Craig
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
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There is supposedly a difference in the torque bias between the AAM and the Eaton, not sure about the Yukon. I'd guess it's an exact copy. I have the AAM Tracrite in mine, you can find them cheap as takeout units from Dodge trucks.
 

N2BRK

Well-known member
Dec 31, 2009
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A Grizzly locker on the street might be great for some hard core guys, but after talking to people about it's DD manners, I went to the Truetrac and I am very happy. Happy enough to buy one again a dozen years later for my current truck! The helical style is invisible until you need it.

As for the differences, when I looked at the AAM I found out that it's bias ratio is 2:1. The Truetrac is 3.5:1. I liked the idea of being able to send more torque to the tire with traction and went Truetrac. If an AMM fell in my lap for cheap though, I'd run it in a heartbeat :)

Yukon shows a ratio of 2:1. Oddly though, they have another field with "End Ratio" of 8. Not sure what that means, but I'd be shocked if it somehow has an 8:1 bias ratio. Maybe someone here knows?
 

16LML

New member
Oct 6, 2019
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Very curious about the Yukon helical and why they feel it commands such a premium over the Tru-Trac. Interesting catch regarding the “end ratio”.

Happy to pay the premium provided it’s for superior design/performance.

These look very interesting as well, but nothing for the 11.5 application:
 
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16LML

New member
Oct 6, 2019
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Alright- so I asked Yukon these questions directly and here is the response:

“I would not recommend the helical as it is merely an aam factory tracrite out of a dodge 11.5. if you want a clutchless LSD i would stick with the truetrac 915a568”

So now we know.
 
  • Wow
Reactions: N2BRK

16LML

New member
Oct 6, 2019
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Yukon is overpriced. If the Eaton and AAM pieces have proven themselves why bother?
Mainly just because I thought there might be some advantage given the higher price point. They can be had for about the same price as the trutrac online, so I thought it warranted further investigation.

Sounds like the Trutrac is the way to go, however….
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
3,470
462
83
Central OH
Kind of odd that they'd admit it was the same. Only so many ways to slice the helical posi bread though. Back when I was searching for a replacement carrier Greenburg Machine in PA had the best all around prices