Tuning Up Front

©By: Jerry Willburn

Formatted for the Morgan Web page by: John T. Blair (WA4OHZ)

Last update: June 14, 2009 - Reformatted page

I will not attempt to go into the pros and cons of decambering your Morgan. Suffice it to say that all of the racers do it, most people recommend it if you use radial ply tires, and our SNOBMOG is not decambered.

To decamber your Morgan, you must move the bottom of the kingpin outboard with respect to the top. This can be accomplished in several ways. On the Le Mans cars, Chris Lawrence had longer bottom tubes made for the cross-axle. The local slalom crowd has been using "Decamber Plates". This is a replacement baseplate with the hole for the kingpin moved 3/4" outboard. This is a very simple modification to make and the only drawback seems to be that a greater strain is put on the two mounting bolts for the baseplate (because of the greater offset). Grade 5 or better bolts should be used here and torque them to 20 lbs. feet.

Editor's Note: I would suggest that you manufacture the new baseplate (see drawing) before starting the following procedure.
The Procedure dot_clear

  • Disassemble the front suspension


    1. Described in the November 1982 Format article (write Jerry Willburn if you desire an additional copy. If you are only installing the decamber plate and not replace the kingpins and bushings, disregard steps 1 to 4 of the disassembly instructions.)
    2. Editor's Note: Also described here the Morgan Web page in Article on "Rebuilding the Front End"
  • The end of the cross-axle will have to be modified for the larger offset. If it has not cracked already over the years, cut away the outer edge of the flange on the cross-axle as shown.

  • Mount the new baseplate to the kingpin and reassemble the suspension. Be sure to use 5/16" grade 5 or better bolts to hold the baseplate to the cross-axle, and to torque them to 20 foot lbs.

  • The last step is to adjust the toe-in. As you have effectively increased the distance between the two front wheels, toe in will be excessive unless the track rod is also lengthened.
    Toe-In Measurement dot_clear
    The easiest method that I have found (aside from taking the car to your friendly local alignment shop) for adjusting toe-in is to use a plumb-bob. Any weight, like a nut on the end of a string, will do.

    1. First, jack up the front of the car, spin the front wheels, and mark the approximate centerline of the tread with a piece of chalk.

    2. With the wheels pointed straight ahead, drop the plumb-bob from both the front and rear centerline of each front wheel. Mark the position of the garage floor with a piece of chalk.

    3. Now, measure the distance rear to rear, front to front, and the diagonals. As in the sketch.

    4. The toe-in is the difference between the front and rear measurements. If the rear distance is greater you have toe-in. If the front measurement is larger, you have toe-out.
You should have 1/8 to 3/16 inch of toe-in. ie. shorter in the front.
Toe-in Adjustment dot_clear
  1. Loosen the stop-nut(s) at the end(s) of the track rods between the front wheels and also the clamp on the rod from the steering drop-arm to the track rod. Note the position of the clamp on the track rod.

  2. Rotate the track rod to lengthen it or to shorten it as required.

    Note: If the front has just been decambered, the rod should be too short and will have to be lengthened (about one inch).

  3. When the toe-in is correct (1/8 to 3/16 inch), tighten the jam-nut(s) on the ends of the track rod.

  4. Tighten the clamp on the tie-rod in the same position that it was in before.
Note: If you forgot to mark the position of the clamp or if you just wanted to check the centering of the steering, do it now before you tighten the clamp on the tie-rod.

dot_clear Enjoy your Morgan

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