Stock Ram L/S VS Detroit TrueTrac

chet6.7

Explorer
I am going to have the R&P changed to 4.10,so I am thinking about getting a True Trac installed as well. Has anyone switched out the stock Torsen L/S for a TrueTrac? Any thoughts are welcome.
Thanks.
 

chet6.7

Explorer
I have not been able to find the torque bias ratio of the AAM TracRite® GT.
I can find the torque bias ratio of the TrueTrac,"The Truetrac can transfer up to 3.5 times more torque to the high traction wheel" Source Eaton

A poster on CF and TDR says, "Truetrac is made by Eaton. The unit in our trucks is a torsen style made by AAM and not as good as a Truetrac. Truetrac is 3.5:1 torque bias the AAM is only 2:1 torque bias."
I can't confirm the AAM torque bias,but he is correct about the TrueTrac torque bias ratio.

"Before differentiation occurs, gear radial and thrust forces generated by the torque on the gears cause frictional forces in the differential between the gear to gear interfaces and gear to case interfaces
Once the frictional forces are overcome, differentiation will occur
The torque will be continually biased, by the frictional forces, to the high traction wheel
Torque bias ratio is tunable by modifying helical gear geometry
Torque to turn (pre-load) is tunable by adjusting the amount of spring pre-load
Increases traction effort on high mu wheel through the multiplication factor of the TBR. Higher TBR of limited slips increases the amount of torque that can be transferred." Source AAM.


Does anyone have any information on adjusting spring pre-load?

 

Buliwyf

Viking with a Hammer
How worried are you, about the difference?

If it's a significant amount, skip it, and get a locker.
 

chet6.7

Explorer
Worried, o_O

If the pre-load of the stock unit can be adjusted I would consider that,if not, the more aggressive torque bias of the TT seems like the better option. A Detroit locker is not what I am looking for.
 

Seabass

Idiot
Any particular reason you are not wanting a Detroit? Quite often I see the tru-trac installed in front diffs and the Detroit in the rear. Although I do know of a few trucks that have tru-tracs in the rear. But they had worn out limited slips to start with or were open. It’s a lot of investment to spend to have something that’s not necessarily a lot better than what you currently have. I’m not saying you’re wrong either. It’s your truck and you need to do what works best for your needs. I am running a Detroit in my daily driven F-350. It weighs 9,000 pounds and I even tow HEAVY regularly. I’ve never had a minute of trouble out of it. Admittedly....I can tell that it’s in the truck. It did effect its handling on the road a bit. But not a lot.
 

Shovel

Explorer
I'm not sure any of it really matters too much since a 2014 Ram 2500 is going to also have BLD which amplifies the effect of any limited slip - I wouldn't want to rely on BLD alone as it can't handle long term mud use (traveling for miles along a constantly slippery mud track) but in combination with the helical limited slip that should be good for just about anything and if you're spending money on traction it might be more wise to try to get a selectable front locker rather than what may be a zero sum trade in the rear.
 

chet6.7

Explorer
I am taking the truck in for a R/P change to 4.10 in a hour. I don't have enough info to make an informed decision so I am not going to change out the stock L/S.:(
I was driving on a long dirt(now muddy)up hill road a week ago,with TC off one tire was doing most of the work. I was thinking of going to the Eaton TT to get better performance as I like to drive dirt roads in all weather.
I have not ridden in a vehicle with a Detroit Locker on the street. I have read for years how much it changes street handling,I know that is subjective.but that I what I have to go on. I don't want to give up my wet asphalt performance in corners for a Detroit locker.
Thanks for the information.
PS, hope to get the 1 inch Thuren front lift and the 2.5 Kings on this week as well, so I can get out on the dirt/mud and see the wildflower bloom.
 

Halligan

Adventurer
Too bad you couldn't find a used 4th gen Power Wagon rear axle to purchase. They'd be geared the way you want, have the LSD for daily street driving, and the locker for the nasty stuff.
 

Buliwyf

Viking with a Hammer
Wet asphalt? Detroit Locker in the rear has no effect on that, unless you have terrible tires and piss poor driving skills. Even then, quality tires go a long way in the rain.

Driven correctly, with the right tires, a rear Detroit can be quite helpful. The outside tire gets to spend nearly 100% of it's grip on side bite stability since it's ratcheting free. We've used Detroit's with slicks in the rain in many race cars.

Ice and poor quality tires and driving habits are the Detroits kryptonite. Much of those issues can be mitigated as well. I'd hate to swap gears in both axles, without at least adding a locker up front.

Of course the Detroit lockers in race cars are specified by the rules. High grip can actually be a problem, and can lead to low grip when the inside tire barely touches the ground in tight turns. Uber expensive electronically active Torsen diffs are best, but aren't good for cost controlled racing. But Detroits are nearly perfect options for such.
 
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chet6.7

Explorer
Wet asphalt? Detroit Locker in the rear has no effect on that, unless you have terrible tires and piss poor driving skills. Even then, quality tires go a long way in the rain.
Googling Detroit Locker in the rain gets some hits,they seem similar to what I have read over the years.

Driven correctly, with the right tires, a rear Detroit can be quite helpful. The outside tire gets to spend nearly 100% of it's grip on side bite stability since it's ratcheting free. We've used Detroit's with slicks in the rain in many race cars.
If it is ratcheting does that mean you are off the throttle? I like to apply power coming out of a corner. I have seen a lot of races, when it rains they come into the pits to switch to a rain tire.

Ice and poor quality tires and driving habits are the Detroits kryptonite. Much of those issues can be mitigated as well. I'd hate to swap gears in both axles, without at least adding a locker up front.
I have to drive in ice,snow,and heavy rain,typical Pac NW weather. I have a CAD,so unless I want to spend another couple of thousand no locker on the front.

Of course the Detroit lockers in race cars are specified by the rules. High grip can actually be a problem, and can lead to low grip when the inside tire barely touches the ground in tight turns. Uber expensive electronically active Torsen diffs are best, but aren't good for cost controlled racing. But Detroits are nearly perfect options for such.
 

Seabass

Idiot
For what it's worth....which is little at this point, the Detroit is nothing to be scared of. Yes if you are in a tight turn on wet pavement the inside tire can slip if you hammer the go pedal. But just driving normal on wet roads....nope. Feels stock. Snow, ice, I've noticed no problems. I do have a manual transmission and the backlash is greater with a Detroit so if I'm not paying attention in a parking lot or doing something that involves rapid deceleration and acceleration I can get some "ratcheting" of sorts. I just clutch it, the ratcheting stops, and I move on. If I hammer hard on dry pavement.... say at a sharp right hand turn, the inside tire chirps and carries on, but it doesn't handle bad. Just looks like I'm an idiot to those around me. But- off road-----there's NO comparison. The truck is night and day different. It's a tank. I'm very, very pleased. In fact I'm fixing to put a Detroit in my other F-350 since I've enjoyed this one so much.
 

Buliwyf

Viking with a Hammer
The Detroit will unlock in turns, even on throttle. Just don't spin the inside tire.

Being a Dodge, I'd make a front freespin kit a priority. IIRC, Yukon might be the cheapest.
 

southofantarctica

New member
I've got a Detroit in my 01 Dakota, shorter wheelbase than what you're playing with (which should make things more noticeable). I have to say I agree with Seabass on the overall performance and "issues", I'd do it again in a heartbeat. The wife even drives the truck fairly often on the street and has no complaint at all. She probably wouldn't be able to tell you I changed anything if she hadn't seen the checkbook.
 
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