Thinking about front and rear Eaton TruTrac's

[LiveOak]

I am looking at having front and rear Eaton TruTrac's installed in the wife's and my truck.  Getting really fed up with getting stuck/tire spine on damp grass and poor off road manners especially in mud & steep forestry roads.  

 

I am trying to figure out an easy way to determine what spline axles are in each of the axles.  Both trucks I am pretty sure I have 3.54 gears in both trucks.  

 

Any comments, opinions, suggestions, and recommendations welcome.  

Edited September 3, 2020 by LiveOak

[That Guy]

My powerlock/traclock works quite well (I forget which it these came with). It makes a huge difference. It is no fun being stuck is the grass because you backed up one foot off the pavement. 

 

Eaton stuff in general is fantastic and very high quality. My chevy has an old Eaton LSD and I couldn't be happier. No issues in chatter/hopping in sharp turns, and it has gone places I didn't think a 2wd was capable of. 

 

As for splines, I couldn't say. 

 

You may also consider a locker, either manual or automatic depending on just how much you go through. Locker>LSD in nasty stuff.

 

The automatic lockers are built with more speed differential in mind before they bite owing to being on/off, where as the LSD will ease in and out with very little slip without notice since even when 'locked' they still allow for some differential.

[Mopar1973Man]

BEWARE... Tire conversation. 

 

That's because of the wider tires. That spreads your axles weight out over larger square inch surface. Like walking on a weak roof you throw down a sheet of plywood to spread your weight over the trusses. This making it easy for the truck to spin on grass or slick, or climbing... I will say "Wider Tires" will make the tires float on top of mud better because of the spreading of weight. But for traction narrower tires bite better for offroading. To this day I've climbed some steep hills, and did well. Another way to look at it... You go outside into the snow and steep in the deep snow you sink right in. Now throw on snow shoes you can walk on top of the snow. Just spreading the weight out so the soft ground doesn't depress... 

 

Typical axle weights...(Roughly)

Front - 4,3xx to 4,5xx

Rear - 2,8xx to 3,2xx

 

Another tidbit I'm also open diff both front and rear. Rare to slip a tire with what I've played in the tire game between 215, 235, 245, and 265s. I would say the 265 were horrid for offroading tend to spin too much. As for the 235's those were awesome bites right in and held good for even dragging full size truck up the bank. 245's not a lot of experience offroad as of yet but soon. Then on my lil 96 Dodge I've got the 215's and those climb really good! Rare to even spin or get stuck.

 

Another secret. I've shown this to several people and it works. If you trying to cross old crusty snow. Wide tires are best but even narrow tires can do it with a twist. If I back over the snow I'm dragging the most weight across the soft snow or mud. When you drive forward the weight of the Cummins will drive the front axle down and sink it. Again for soft ground (mud) the wider tires are best. Snow on the highway, narrow is best for highway traction. Again small patch of tire will push down to the asphalt easier to bite.

 

I'm considering going up with a nicer set of wheels but I know it going to require a wider face tire like 265 to 285. But I'm going to keep my 30 inch size. Aluminum wheels...

 

I'm about 200 feet above the road below... 4 wheel drive and climb the face. (235's)

 

 

[That Guy]

I have experienced the front axle load of the Cummins more that once. It will instantly sink to the axle/frame given the chance.

 

Last time I was on scales, F~4300, R~3000.

 

Narrow tires do indeed bite harder.

[Towrigdually]

So running a full locker front and rear myself. I would highly suggest putting a free spin kit on the front if you go with a mechanical locker. Looking back I should have put in a air locker in the front. 

[Joe_Pool]

2000 - 2002 should be 32 spline front (1994 - 1999 should be 30 spline) and 35 spline rear.  I suggest pulling at least one front inner shaft to confirm the spline count.  I prefer ARB air lockers so I can control when they are open or locked.  A locked front diff is a pain unless going in a straight line (hard to steer), but will keep you moving and most LS differentials will cause some torque steer.

Edited September 4, 2020 by Joe_Pool
To add information

[LiveOak]

The Eaton TruTrac is not a differential locker per se.  It is substantially similar to the Torsen differential:

 

Torsen Differential

 

The Eaton TruTrac achieves similar if not stronger results:

 

Eaton TruTrac Exploded

 

The Eaton TruTrac to my understanding provides the best of both worlds in that it provides a locking function but does allow axle differentiation thus minimizing torque steer in frront axle applications.  I think this guy can explain it better than I can starting at 5:20 if you don't want to listen to the entire presentation:

 

Differential Locker Comparison

[That Guy]

Sold me, except, many of us are running factory limited slips that still function with several hundred thousand on the clock. Maybe he is referring to 20,000 off road miles?

[LiveOak]

Agree.  If I had a factory limited slip, I would not be replacing it. I think I would just add a front TruTrac in that case.  I have open diff's front and rear and they REALLY suck in mud or even damp grass.  Having a front limited slip differential that does not affect steering dramatically is a BIG plus for me as I am on logging roads from time to time.  I kinda had my doubts and did an eye roll on the 20,000 mile thing too.  

[Joe_Pool]

Correct me if I'm wrong, but I do not think that a 32 spline Dana 60 Truetrac is available (only 30 spline front and 35 spline rear for D60 2nd Gen Rams).

[LiveOak]

I'm not sure.  I am still researching this.  

[AH64ID]

Having ran clutch style, helical style, and selectable locker differentials I will say this.
 

Helical or selectable, period. 

 

I friggin hate clutch style LSD’s, they are unpredictable and dangerous on ice. 
 

Helical gear are great for most situations, aside from being stopped and needing traction. They require some sort of movement to transfer torque, which can be an issue. 
 

Selectable's are amazing, open when unlocked and locked when needed. There is nothing white like an open differential for lateral traction on snow and ice. 
 

Long story short, I think you will really like the tru-trac’s. They have a great reputation front and rear. 

[That Guy]

Unpredictable is an automatic locker. You are going up a steep switchback road on the side of a mountain in a truck with nothing in the bed in a light drizzle, start to slip a little... next thing you feel a clunk, and then you are sideways. Luckily you were only doing 15-20 mph. I'll take a limited slip before an automatic locker... road manners are much more predictable, everything being relative.

 

But, I think the torsen style may be the best of both worlds. The guy in the video said that if you apply the brake a little it will give enough torque to lock up the torsen and away you go. 

 

In the name of selectable lockers.... I had my hands on a 6x6 Pinzgauer. Had all hydraulic controls for the lockers and transfer case. Thing would walk through anything, and portals meant it would clear most anything too. 

[AH64ID]

Minus the clunk that is how clutch LSD’s have worked for me. I find they engage when you don’t want them to, such as on ice, and don’t when you need them. I have ran multiple versions of clutch style LSD’s and I find them all the same, overrated and predictably unpredictable. 
 

I’ve never ran a auto locker as I’ve never had a dedicated trail rig, and even if I did I’d probably run a selectable. 
 

[gerlbaum]

On 9/4/2020 at 9:17 AM, Towrigdually said:

So running a full locker front and rear myself. I would highly suggest putting a free spin kit on the front if you go with a mechanical locker. Looking back I should have put in a air locker in the front. 

Yes! Or at least selectable front. I had a mechanical front and rear on a off-road only Jeep. If you were in 4wd and the front locked you were going straight whether you wanted to or not.

 

W/o lockers, 2wd is really 1wd and 4wd is really 2wd.

[Towrigdually]

13 hours ago, gerlbaum said:

Yes! Or at least selectable front. I had a mechanical front and rear on a off-road only Jeep. If you were in 4wd and the front locked you were going straight whether you wanted to or not.

 

W/o lockers, 2wd is really 1wd and 4wd is really 2wd.

I should have done that also, but at the time I was trying to get the truck into pulling, but things happen.
I have Yukon lockers in the Rockwell axles under the mud truck and those will pull whatever they want if you don’t aim it early, especially on tractor tires. 

[LiveOak]

OK, here is the deal on traction aid devices on my particular 2nd Gen 2002 2500 but this applies to 00 - 02 2500's & 3500's.  The rear axle being a Dana 80 is compatible with the Eaton TruTrac Part # 915A567.  This in my opinion is the best limited slip/locking device for the rear axle.  

 

The front axle on the other had is an odd duck thanks to Dodge cheaping out and electing to buy 32 spline Dana 60 front axles.  There aside from an ARB Locker and some other axle lockers that are NOT suitable for full time use on public roads, there is as far as I am aware of ONLY 1 traction device made for this particular front Dana 60 32 spline axle that Dodge used on their 00 - 02 trucks and that is the Yukon Dura Grip clutch pack type limited slip differential.  This is not an ideal solution albeit the only solution but from others I have spoken with tell me that it will work pretty good.  

 

The other solution that will allow the installation of the Eaton TruTrac Part # 915A367 is to buy and modify an older front Dana 60 35 spline axle to fit on my truck from a Dodge or Ford or install the Syntec Upgrade kit that upgrades the outer stub axles to 35 spline and then find of have custom made 35 spline inner axles to the differential carrier.  This mod would run into the thousands of dollars plus the cost of the TruTrac, and the cost of installation.  Not worth the hassle for the periodic off road driving I do managing our forestry units.  

 

Figured I would pass this along so anyone else with a 00 - 02 2nd gen truck who is fed up with getting stuck off road will know of this option.  Rock Auto sells the Yukon Dura Grip differential for about $565.  I like dealing with Summit Performance so I called them and they price matched it.  They also price match the Eaton TruTrac.  

 

Dodge is such A-holes & jerks for what they did to the 00 - 02 2nd Gen trucks.  They cheaped out and cut corners on these trucks in so many places but it was the last year they made mine and I figured they would have all of the bugs out of them.  I figured WRONG.  My biggest peevs are Dodge deleting the CAD system on the front axle, eliminating the fender well liners, and the hood insulation.  There are other peevs but they are minor or design flaws like the Carter block mounted lift pump.  

 

Hope this helps the next guy out who wants better off road traction with the front axle.  

[Joe_Pool]

You could also upgrade the inner shafts to 35 spline and install a 35 spline Eaton for a D60.  No need to change out the entire axle.

[gerlbaum]

I've been told but never actually confirmed this: Can you run a small difference in gearing between a front and real axle? For example, can you run a 3.54 rear end and 3.55 gears up front (or vise versa)?

Edited September 17, 2020 by gerlbaum

[LiveOak]

9 minutes ago, Joe_Pool said:

You could also upgrade the inner shafts to 35 spline and install a 35 spline Eaton for a D60.  No need to change out the entire axle.

 

Talking with Joey Sanchez @ 4WDFACTORY.com tells me that I can install the guts/axles from a 99 or earlier CAD front Dana 60 in theory which are 35 spline axles but there is not CAD mount on my axle nor the vaccum tubing and asscociated brackets & hardware.  The axles would cost about $700.  The caveat is that they have NEVER done this axle upgrade in their shop and I am pretty confident neither has any other reputable shop that I am aware of.  Just too much unknown and complication.  Hence elected to go with the Yukon Dura Grip.  The 32 spline axles are strong enough for what I can throw at them and Yukon tells me that others use the Dura Grip in their front Dana 60's for pulling trucks and other competition use with good results.