The article discusses a number of developments intended to overcome the problem of wheel-spin encountered in American-designed vehicles with a driven line axle, caused by the output torque being applied to the right hand wheel. A device to overcome this problem is the positrac unit that comprises two free-wheels which apply driving torque to the slowest wheel and engine braking to the fastest wheel. Another device developed by Eaton Corp. is an automatic self-locking differential which only comes into operation when wheelspin occurs. Another self-locking differential unit is the true-trac device developed by Aspro Inc. which is designed to differences of torque rather than speed. Such devices are useful in exploiting the advantages of four-wheel-drive transmission layouts in which torque can be applied equally to both axles. In such layouts it is the practice in the United States to fit automatic locking front wheel hubs so that the front transmission system can be at rest on good surfaces. /TRRL/

  • Corporate Authors:

    Design Engineering Publications Limited

    89 Blackfriars Road
    London SE1,   England 
  • Authors:
    • Firth, B W
  • Publication Date: 1974-10

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00097866
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Sep 30 1975 12:00AM