Swapping Auburn LSD for Powertrax Grip Pro

So, I'm planning on swapping my Auburn Pro LSD out for a the Powertrax Grip Pro. I'm doubtful that anybody has experience with both, but, anybody have experience with both? I've seen a few posts about the axle shafts being problematic on install, but aside from that, any other issues with the unit?

Why for am I swapping out the Auburn? With 100k miles on it, surprisingly it still works like a charm. I've kept up on gear oil changes and running the proper amount of friction modifier. Plus, I don't try to make skid marks down the road, nor do I hammer it off pavement or in the snow, so I'm not too surprised that it's still working well. But the differential certainly lets me know when it's sheared up the friction modifier. I'm thinking the with the constant load I carry around combined with towing, it just goes through the friction modifier more quickly than most users would.

Even with the increased maintenance, that's not a big enough issue to make me not like the Auburn. I really just wanted a helical gear limited slip from the get-go, but nobody offered one for the truck when I installed the Auburn. I was really hoping Eaton would step up with a TruTrac. So the auburn will come out and the Grip Pro will go in. I'm also curious to see how well the bearings are holding up. My installer was able to reuse the original bearings but I'm betting he won't be able to reuse them this go around. Summit was willing to price match a lower price I found on the Grip Pro and I've got a shim kit from last install.

Plus, I think a torsen rear diff will only complement the torsen diff in the sequoia t-case sitting in my shop ready to install

 

@Mdl will shortly:
https://www.tundras.com/threads/general-supercharger-thread.85513/page-319#post-3252448

 

Awesome. Thanks for tagging him. Interested to see what he has to say.

I'm also trying to resist the temptation to install 4.88's while I'm in there. Still rocking stock size tires but am considering 275/70's again. And my boys sure would dig some 285/75r18's. Or 295/70's.. As much as I like this game, I kinda hate it too.. Er, my wallet hates it...

 

Installing the Powertrax is on my list but I have to get my engine dialed in first. Probably be a few months before I get into it. Glad to hear your Auburn is doing well. I would think that they solved their manufacturing process to get a better fit. Hopefully earlier diffs would be already out of inventory. Changing out bearings would be ideal as you are already in it. I would test fit the axle and dif before hand but really haven't read too many that HD the tighter tolerances on the diff diameter. The Auburn swap was pretty easy. My biggest issue was benching that thing up into place before the fipg dried. Ha
I haven't re-geard and run 315/70/17 dick cepek extreme country with no perceived issues.

 

Santa showed up today. Waiting to hear back from my installer to get it done. My guess is it will be a few weeks. Looks smaller than the auburn if I remember it correctly.

 

I had the auburn on my prior 2010. I have the GripPro in my current 2017. Overall I much prefer the Powertrax. No clutch materials to wear out, and it locks up super positively every time you would expect it to which I didn’t feel the same with the auburn. Short of having a wheel totally off the ground which I’ve not tried, the powertrax always seems to be putting power down to both wheels quite well. My installer said the axles were snug but went in ok. I’m using valvoline 80/90 regular gear oil. I think you will love it.

 

Good to know. That’s what I’m going for.

 

How does this play with the Tundra's traction control/braking system? Or does that have to be disabled?

 

It doesn’t cause any issues, if anything it keeps that junk system from ever engaging. The only time it may come into play is if you use auto LSD in low speed offroad situations which will likely only aid the action of the LSD as it brakes the slipping wheel.

 

I have the grip pro with 4.88’s and it works great. Buy the gears from your installer in case they are noisy and need to be replaced. Their dime, not yours.

 

My experience has been the same with the Auburn. Unless both tires start spinning (such as trying to start out on an icy road) the traction control rarely kicks in. And in the icy road scenario, you have twice as much traction since both wheels have to be spinning for it to kick in, rather than one wheel. I’ve not noticed any adverse affects from and ABS/traction control standpoint.

As far as the ALSD system, it actually plays quite nicely with the Auburn, transferring more power much faster to the wheel that’s slipping. I’ve had a few times climbing up rutted and rocky/gravelly two track where you would feel a wheel start to slip then almost instantly you feel the power transferred to the other wheels. I notice because I’m looking for it and am familiar with how the truck drives with open diffs and with just the Auburn without an electronic Nannie’s.

So, IME, it has only been helpful in ALL driving situation and has not caused any issues.

 

@blenton, curious to hear your feedback now that you've had the Powertrax installed. I'm considering changing out an Auburn for the Powertrax as well.

 

I believe he picked up and installed a Speedmaster LSD over the powertrax.

 

Just curious, what are you doing with the Auburn after it’s removed?

 

Like @Mdl said, I ended up installing the Speedmaster LSD instead of the Powertrax, but both of them are helical gear torsen-type LSD’s so I would expect them to perform similarly.

Compared to the Auburn, the torsen type diff wins hands down. I say that knowing I got my moneys worth out of the Auburn and appreciating the additional traction it provided over an open diff. My issues with the Aurburn were related to the friction modifier; after talking with some folks more knowledgeable than I, having 4.30 gears and doing a lot of towing and hauling contributed the FM shearing down prematurely. It was only lasting a few thousand miles towards the end before the clunk and chunk returned. I think 20k miles is the most I ever got out of it before it became intolerable. I typically drive that much each year.

The clunk and chunk was disconcerting in some instances, but annoying in all situations. In the winter on icy roads it made low speed turns a little unpredictable as the clutches would lock and release, sometimes causing the front wheels to snow play in parking lots and such.

So far, the torsen type is far superior in all situations save straight line, low traction, low speed takeoff situations like icy roads. One tire will spin a hair sooner with the Speedmaster than the auburn; that is to be expected based on the basic operating principles of each unit. The Auburn is basically engaged by default, “unlocking” in turns or when torque bias is exceeded (as in heavy throttle, one tire poor traction). The torsen is basically partially “unlocked” by default, allowing low throttle, low speed operation similar feeling to an open diff. But as long as you have SOME traction to both wheels, it will progressively bias more traction to the wheels until there is no traction. I’m sure that’s not a great explanation of it, but hopefully you get the gist.

In short, it was well worth it to me. The torsen feels like an open diff until you feed it some throttle, then it does it’s job. It feels like you are pushing more power to each wheel rather than hoping the diff will hold power to each wheel. If you are considering it and have the funds, I have zero regrets about doing it.

Yup. But I still have the Powertrax waiting to go in my ‘21 once I get the blower sorted on the ‘13 and can start driving it again. Hoping to have it installed sometime early this summer.

Wall art?? Paperweight? Not sure, TBH. I thought about pulling it apart just to give it a post-mortem inspection, but my heart isn’t set on it.

 

If be interested in the tear down

 

Looking at the unit, it shouldn’t be difficult. I think there’s one set screw/through bolt, then one half of the case threads in to the other half.

 

Paging @texoma

 

Inside the case…

 

Some good scraping on that thing

 

Ya, no joke. I was surprised by a couple of things as I was pulling it apart - and not necessarily in a good way.

- A year or two ago, it was acting up pretty bad so I did a drain and fill with only 3k miles or so on the oil and additive. My magnetic drain plug had a thumbnail clipping sized piece of metal on it. I really didn't get anything more than fine wear metals out of the diff on regular oil changes except for a few times I got tiny pieces of metal, but somehow that piece was in there. I think I know where it came from, though...

- Looking at the two pics of the backside of the side gears, they are pressed in to the cone clutch assembly - which is fine, but there is no relief/bevel machining on the backside of the cone clutch, resulting in a very thin metal strip at the bottom. I believe that metal piece came directly off of the backside of the side gear assembly and made its way through the assembly, wreaking havoc as it went. You can see another piece ready to detach at the same place.

- For being so 'precision machined' I'm surprised by the amount of wear on the backside of the side gear assembly. Not only is it excessive, but uneven. Almost like the side gear wasn't pressed correctly in to the cone clutch, causing it to be canted ever so slightly. But I think it's just how the unit wore.

- Holy smokes the thrust washers on the spider gears marred up the case!

- I pulled out the calipers and measured the surface area of the actual clutch area cone clutch. I assumed it would be the entire beveled area around the side gears, but it's only small, ~3/4"^2 pads. There are six pads on each gear, for a grand total of 9.36 in^2 of clutch surface area. That doesn't sound like a whole lot to me... There obviously isn't a spec clutch material left in the contact zone.

- Due to the small surface are of the clutch pads and high pressure on each part (I'm speculating here..) you can see chatter marks on the case mating surface area. I don't race the truck or hot dog it on high traction surfaces.