Humber   Hillman
Sunbeam

Rootes

Private and confidential
Service Bulletin

 L. 14.
  

August 1966

Model:

Subject:

Imp, Chamois & Van

Excessive rear tyre wear

As a result of recent investigations into isolated cases of excessive rear tyre wear, it has been established that this can be due to excessive rear wheel toe-in.

Should you be called upon to investigate such a complaint, it is recommended the following procedure is carried out:

  1. Using gap gauges (car or van as appropriate) as detailed in section F of W.S.M. 141, check rear wheel toe-in. The correct figures ahould be:
    5/16" (7.9mm) ± 1/8" (3.1mm) measured at tyre tread.
    Equivalent to an angle between wheels of 50' ± 20'.

    Note: If toe-in measured on wheel rim ortypre side wall, the reading obtained must be converted to correspond with a tyre diameter of 22" (56cm).

  2. Establish whether one wheel is toe-ing in more than the other, relative to the centre line as the car as follows:

    1. Set front wheels to the exact straight ahead position.
    2. Stretch a suitable piece of string tightly around all four wheels as shown in illustration no. 8876 ensuring that the string is clear of the body sills.
    3. Check the distance between the string and centre tread of tyre at positions X & Y.

  3. If toe-in is in excess of specification, carry out operations A, B, or C shown overleaf according to toe-in figure obtained.

  4. Where necessary make up and fit mild steel packing plates as per illustration no. 8874. Packing plates must be inserted between the cross member and the rear floor heelboard panel vertical face as shown in illustration no. 8875.

  5. The rear suspension arm pivot bushes Part No. 7102010 must always be replaced.

  6. The following points are given for your guidance and must be strictly adhered to when carrying out the above work:

    1. When re-fitting cross member, first evenly tighten the horizontal attachment bolts and finally the vertical (underside) bolts.
      Torque load all attachment bolts to 27 lbs.ft. (3.7 kg/m.)
    2. When packing plates are employed, it may be found necessary to slightly elongate the existing oval attachment bolt holes on the underside of the cross member.
    3. The suspension arm pivot bolts must be tightened to 43 lbs.ft (5.9 kg/m) with the vehicle in a free standing condition.
    4. The packing plates must be made to the exact thickness and dimensions shown in the illustration.
    5. No more than two packing plates per vehicle must be used.

Please bring this information to the immediate attention of all Parts and Service personnel.

 

Toe-in Toe-in Equal each side
(i.e. less than 1/8" difference between X and Y)		 Toe-in Unequal
(i.e. difference between X and Y greater than 1/8")
A)
Between 7/16" and 1/2" at tyre tread
(1.1cm to 1.27cm)
  1. Renew pivot bushes in both suspension arms
  2. Fit one packing plate at outer mounting point on the side showing greater toe-in
  3. Re-check toe-in
  1. Renew pivot bushes in both suspension arms
  2. Fit one packing plate at outer mounting each side of vehicle
  3. Re-check toe-in
B)
Between 1/2" and 9/16" at tyre tread
(1.27cm to 1.42cm)
  1. Renew pivot bushes in both suspension arms
  2. Fit one packing plate at outer mounting each side of vehicle
  3. Re-check toe-in
  1. Renew pivot bushes in both suspension arms
  2. Fit two packing plates at outer mounting point on the side showing greater toe-in
  3. Re-check toe-in
C)
In excess of 9/16" (1.42cm) at tyre tread
  1. Renew pivot bushes in both suspension arms
  2. Renew cross member (Saloon Part No. 7102001, Van Part No. 7103013).
  3. Re-check toe-in. If above 7/16" (1.1cm) use appropriate plates as described in A or B above."

 

illustration no. 8876

illustration no. 8874

illustration no. 8875

 

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