Eaton owns detroit true trac now...So there you go. I prefer the EATON clutch style posi. It has been around for years and is a great design peice of equipment that rarely fails. We installl these on all the local street strip cars and 28 spline aftermarket axles...THEN good have fun.
We have EAton posi units and true trac if you need a price quote for a posi and or axle package. PM us. Jim
are either of those torque sensitive? i mean, i'd like to get a posi...but my understanding has always been that they lock based on one wheel spinning. so, off the line you wouldn't have true posi traction until one wheel turned 100 rpm faster than the other. does that make sense? i want a posi unit that would lock right off the line...if i get one. if not, i'm getting a spool.
Eaton performance posi is always locked and working straight away...NEVER turn off and only releases/slips (where we get the term limited slip) in turns to let the outside tire turn faster and travel more distance than the inside tire.
The true trac work form inertial torque sensing force. Meaning the helical gear will slide from side to side when forces of lateral and toque are applied. This true trac posi is really a better road racing posi unit to keep the car more controlled and well manner in corners.
The Eaton Governed lock unit is probably what your referring to . IT locks and unlocks only when needed and has a ramp gear to provide the slip sensing of the rear wheels in relationship to slippage and traction of each wheel.
WE call them grenade LOCKS...lol. If you catch them in the transition between lock and unlock stae under full torque...KABOOM!
Hope this helps.
As stated give a call will hook you up with a great price and all the customer support you can handle...LOL Jim
The Eaton units apply force against the clutch pack as torque input is increased, effectively applying power to both wheels under acceleration. They' not locked all the time. If you give it too much gas in the corner, it doesn't unlock either.
Auburn units work similarly, but use cone clutches that get forced against their seats to accomplish the same thing. They offer a little more torque biasing than an Eaton which technically translates into a more "locked" axle, but most drag guys like the Eaton because of the ease of rebuild. The Auburn is rebuildable, too, contrary to popular belief.
Gear diffs like the Gleason or the True Trac usually have the most torque biasing, but many road racers & oval trackers don't like them because under decelration they still try to limit rear wheel slip which can cause the car to feel unstable. Many road racers actually like lockers best.
Eaton and auburn are always on that is what the preload springs are for. The preload springs are for low torque application until the gas is gunned then the forces take over beyond the preload springs. ASk Toms differentials about how he does not even use preload springs for posi is is truely a wonder and it is very tough to get everything just right with out burning out the spider gears... lol.
In corners they will stay locked because thew weight that would normally be on the vehicle is redistributed and as stated before the clutch and cone friction type units are ALWAYS working...Clutches only slip when the forces are over come by the axles spinning at different speeds from each other or something else will give like a axle shaft of TIRE spin. So if you have a 800 pound preload your tires will be chirping in the corners because the force to over come the clutch pack is greater then the axles torque to the inside tire in the turn.
Oh just for everyone knowledge the eaton gov lock is a clutch base unit also. Driving normal it works as an open differential and when the ramp gear senses loss of traction from left to the right tire ( usually one full revolution) then the unit will lock or engage the clutch pack system with a little toggle trigger..BUT this only happens at low engine speed.
As far as the torsen units I am not fully sold on its design...I will give them about 10 year and see the condition of some of these units. which is coming up pretty fast here. Everyone thinks they do not wear...But I tell you metal to metal touches , IT IS WEARING...lol. The torsens are also a very hot running unit which is a good reason for using synthetic with these units.
Anyway at least people will get more out of this thread the more we put into it. Jim
so it sounds like an eaton posi unit is what i'd be after. it has both wheels locked from a stop and allows wheel speed diff for turning and such. i was thinking of a det. locker...but i have to go 9" for that. these are just thoughts. not sure what i'm doing yet. i'd love to get away from having a spooled rear for street use, but don't want to give up traction at the dragstrip.