AAM Anti lock rear axle

[RPosey]

Will someone explain how the differential is locked up using the so called helix gear.

 

[rbattelle]

From the service manual:



"When one wheel begins to spin the pinion gears on that side are forced toward the pinion brake shoes. The pinion brake shoes cause frictional drag on the opposite pinion gears and the side gear. These friction forces transfer the power to the opposite wheel. Once the friction forces are overcome, differentiation will occur. The torque will be continually biased by the frictional forces to the high-traction wheel"



Or, in plainer terms, the speed difference between the axles during a slip condition causes a transverse force on the side gears which generates friction against a series of brake shoes. That friction force is transmitted across the pinion gears to the non-spinning axle. Obviously, there is a limit to how much extra torque can be generated by this system: the better-designed the system, the more torque it can generate. Ours, unfortunately, is not particularly "good" (in my opinion).



If you're willing to pay the fee, I can point you toward a very good SAE article on the principle of a torsen-type limited slip system (which is basically what we have).

 

[RPosey]

Thanks Rbattelle, Now I wonder if thoose brake shoes wear out. I don't have a problem,I was just curious as to how it works

 

[Winston Wolf]

As I understand it, our AAM axles use this diff:



http://www.aam.com/technology/tech_prod_dl_diff.html#TRGT



While that is not a particularly enlightening explanation of how it works, I believe this particular design is supposed to have less wear parts and should last longer than traditional limited slip designs.

 

[Gypsyman]

As a side note. I just ordered a factory AAM TracRite GT thru Randys Ring & Pinion for $517 vs dodgeparts.com at $1014 .



Richard

 

[rbattelle]

Thanks Rbattelle, Now I wonder if thoose brake shoes wear out. I don't have a problem,I was just curious as to how it works

By definition, any friction part will wear out. However, those little brake shoes are used so infrequently that they will probably never wear out during even a million miles of driving.



But when they do wear out, I believe it will not only render the limited slip feature impotent, but actually require replacement of the entire differential assembly. This is my opinion based on what I know about how this type of setup works.

 

[Yo Hoot]

I do not believe there are any friction devices like clutches or brake shoes.



All geared torsen style is what it is.

 

[rbattelle]

I do not believe there are any friction devices like clutches or brake shoes.



All geared torsen style is what it is.

There is no mechanical system that I'm aware of (except fluid-based like a torque convertor) that will allow torque transfer through slipping shafts without friction. How do you transfer a force from one component to another without friction? In other words, what's the force carrier mechanism?



Besides, the '03 service manual contains a drawing showing the pinion brake shoes.