Section 07-03B: Transmission, Manual, Model S5-47 ZF
1996 F-Series Vehicles Over 8500 lbs. GVW Workshop Manual
CLEANING AND INSPECTION

Synchronizers

 

Synchronizer Ring/Synchronizer Body Wear Check

Inspect the internal surface for contact pattern. The contact pattern should be the same on the entire internal circumference of the ring.

Position the synchronizer ring on the synchronizer body as shown in the illustration. Insert a feeler gauge and measure clearance at two opposite points. If clearance is less than 0.6mm (0.024 inch) for the 3rd-4th, 1st-2nd and 5th synchronizers (7124) and 0.4mm (0.016 inch) for the reverse synchronizers, replace the synchronizer, affected mainshaft gear, or both if required to bring to within specification.



Synchronizer Compression Spring Tension Check

 

Check the length of all compression springs of synchronizers.

SPRING SPECIFICATIONS
Unloaded LengthO.D.Wire Diameter
14.8mm (Min.)
(0.583 In.)		5.960mm
(0.235 In.)		0.95mm
(0.037 In.)

Mainshaft and Input Shaft Gears

  1. Inspect the friction taper cone on the gears and check for the following wear patterns.

    1. Sporadic slightly darkened patches on otherwise evenly smoothed circumference is acceptable. The patches will appear to be blackish in color and will vary in degree and surface area depending on the synchronizer ring contact area.
    1. Signs of excessive heat will appear to be burnt to a reddish-blue color, mainly on the edges of the cone. This is a result of excessive overloading, operating failure or perhaps a malfunctioning clutch system.

  1. Replace gears showing excessively burnt spots (reddish-blue) on the friction taper cone edges. In this case, the selector teeth will be damaged as well.

  1. Reuse the gears if sufficient synchronizer reserve allowance is available and the teeth (dog teeth) are in good condition. Acceptable wear patterns are depicted in the following illustration.





Shift Fork/Sliding Sleeve

Check the contact surfaces of the shift fork and sliding hub sleeve for evidence of wear or damage.

Synchronizer Body

  1. Check operation of sliding sleeve installed onto synchronizer body.

  1. Position synchronizer body and sleeve horizontally. Lift the synchronizer body approximately three-quarters of the way off the sleeve. Release the synchronizer body, and observe downward motion. Synchronizer body should slide downward into sleeve on its own. It should not be necessary to push synchronizer body into sleeve. Service as necessary.