Single Plate Clutch

Single Plate Clutch

The new single plate clutch now standard for Model “A”cars and “AA”trucks is composed of two major units, namely, the cover plate assembly A-7563 and the clutch disc assembly A-7550 or AA-7550.

The cover plate assembly consists of a cast iron outer driving plate and a stamped cover plate in which are mounted twelve pressure springs and six release levers. These springs are in direct action against the pressure plate and automatically compensate for all wear of the friction facings. This feature eliminates any necessity of adjusting the release levers.

The driven member or clutch disc assembly is composed of a flat steel disc and two friction facings. The facings are riveted to both sides of the driven disc. The disc is slightly dished in the form of a cone. With this construction the outer and inner edges of the clutch disc facing, start to engage first and as the clutch engages when the pedal is allowed to come back the spring pressure in the clutch flattens out the clutch disc and the entire lining surface picks up the load evenly. This feature assures exceptionally smooth clutch engagement.

Moulded friction facings are used because of their long wearing qualities. They also successfully withstand higher temperatures as they contain no cotton element.

Repair parts and exchanges

The only repair parts dealers will stock are the clutch disc assemblies A and AA-7550, clutch disc facings A-7549B and AA-7549, facing rivets A-22993 and pressure plate and cover assembly A-7563.

Should any part of.the pressure plate and cover assembly fail, return the entire assembly to the Branch, and a new assembly will be furnished at an exchange price of $3.25 net. The price to the customer will be $4.25.

Under no circumstances will dealers attempt to replace any parts in the pressure plate and cover assembly, as the lever height when under spring pressure must be set with specially designed fixtures.

The following is a list of single plate clutch and related parts which will be supplied through service:

((Table pg 296))

Service Suggestions

((602))

The pressure springs automatically compensate for all wear of the friction facings. Readjustment of the release levers must never be made under any circumstances.

The only adjustment for clutch wear is made at the bottom of the clutch pedal. The pedal must have 1 inch free play or movement before it starts to disengage the clutch.

Grease on friction facings will cause the clutch to chatter during engagement or sometimes slip at high speeds. The remedy is to remove the clutch and install a new set of clutch discs facings.

Occasionally, due to an improperly adjusted clutch pedal o r continuous abusive slippage, the clutch pressure plate may develop small radial heat cracks. If the pressure plate is not grooved, and these cracks are not large, simply polish the face and replace the unit. These heat checks will cause no harm.

It is not necessary to return clutch driven members to the factory for replacement of worn friction facings, as this operation may be done in your own shop. Before facings are replaced, make certain that the driven member otherwise is in good condition.

The saw steel driven disc is slightly dished to provide smooth clutch engagement. When new friction facings are installed be certain that the rivets are drawn down tightly.

Drivers should b e instructed that riding the clutch pedal is a bad habit, as it causes the clutch to slip. The foot should be placed upon the clutch pedal for a definite purpose only—that is to change gears.

New Solid Brake Cross Shaft

New Solid Brake Cross Shaft

A new service brake cross shaft assembly has been designed and is now standard on all cars and trucks. The new shaft replaces the old style cross shaft and equalizer assembly, as the old assembly is obsolete and will not be carried for service.

The new shaft is unusually efficient, simple in design and reduces the number of cross shaft parts.

The following parts are required to install the new service brake shaft assembly for car and truck:

((Table top of 298))

The following cross shaft and equalizer parts are obsolete and will not be supplied after present stocks are exhausted. If any of these parts are ordered, the parts necessary to install the new brake cross shaft should be furnished at the price of the part or parts so desired.

((Table left column 298))

When the solid brake cross shaft is installed on cars equipped with adjustable brake rods, it will be necessary to substitute A-2466 adjust- able eye for the A-2461 clevis on the rear rods.

When installing solid brake cross shaft on cars and trucks equipped with hand brake lever at side, an A-2491-R or AA-2491-R cross shaft guide must be installed (see Figs. 603 and 604).

((603 + 604))

The brake rod holes in cross member must also be enlarged to provide sufficient clearance for the brake rods (see Figs. 603 and 604).

When used on cars equipped with solid brake rods, it will be necessary to change the solid rods into adjustable rods.

This can be done by sawing off the ends of all four rods 33″ from the center of the button on the rods (see Fig. 605) and running a 5/16—24 thread back 2″ from the end of the rod, then installing locknut A-21700 and adjustable eye A-2466. The length of the rod measured from the centerline of both eyes should then be adjusted to not more than 51 7/16 or less than 51 1/2 (see Fig. 605).

((605))

When installing a solid brake cross shaft on trucks equipped with adjustable front brake rods, it will be necessary to shorten the intermediate rod AA-2500. This is done by sawing 5/8” off either end of rod, threading the rod 2” back with a 5/16—24 die and installing lock nut A-21700 and adjustable eye A-2466. The length of the rod measured from the centerline of both eyes should then be adjusted so that it measures not less than 38 5/8 or more than 38 11/16 (see Fig. 605).

When installing the new cross shaft on trucks equipped with solid front brake rods, it will be necessary to make an adjustable rod out of the front rods in the same manner as described for the car. It will also be necessary to rework the intermediate rod AA-2500 as described in preceding paragraph.

((606))

Installation and Adjustment

The oilless type bearings on the ends of the new solid brake cross shaft are assembled to the frame by the use of A-2479-B shims and A-2478-B brackets (see Fig. 606). When assembling, a small amount of grease is required in bracket as the outside of the bearing must rotate slightly inside of the bracket in order to preserve alignment when flexure of the frame occurs.

After installing cross shaft install brake pedal to cross shaft rod. The adjustable clevis end of the rod is assembled to the brake pedal—the non-adjustable end, to the lever on the cross shaft (see Fig. 606).

A slightly different procedure is followed in adjusting this rod depending on whether the car is equipped with a single plate clutch or a multiple disc clutch as the brake pedals used on cars equipped with the single plate clutch are provided with a stop.

If the car is equipped with a multiple disc clutch adjust the rod as follows: Hold the tip of the rod against the rear flange of the center cross member, then adjust the clevis on the opposite end of the rod until the brake pedal arm clears the underside of No. 1 floor board by 1/2” to 3/4”.

If the car is equipped with a single plate clutch, pull the brake pedal all the way back until it is against its stop—then adjust the rod until there is approximately 1/16” clearance between end of rod and rear flange of center cross member (leaving a little clearance between end of rod and cross member prevents any possibility of the end of the rod rubbing against the cross member and causing a squeak).

After adjusting the break pedal to cross shaft rod, assemble side pull rods to brake operating and cross shaft end levers. When assembling the side pull rods, pull the brake operating levers on the front axle back and the brake operating levers on the rear axle forward (taking up all idle movement). Then with the levers in this position adjust the length of the side pull rods so they can be assembled to brake operating and cross shaft end levers.

Next adjust brakes by turning up the adjusting wedges as described on page 202 of the January, 1928, Bulletin.

After the brake rods have been correctly adjusted car owners should be notified that this adjustment must not be altered. Service brake adjustments must be made only by means of the adjusting wedge at each brake.

Generator Charge Rate

Should be adjusted to suit individual requirements. For average driving during cold weather a charging rate of 10 amperes at 1500 R. P. M. will prove satisfactory.

Phaeton and Roadster Door Handles

The new inside and outside door handles which are now furnished as standard equipment on open cars can be easily installed on Phaetons and Roadsters not so equipped, by proceeding as follows:

  1. Remove old lock.
  2. Place new lock in place, fastening with two screws to locate.
  3. Drill through square hole in lock dog, using a 11/32-inch diameter drill. Drill squarely through outside panel.
  4. Using a 1/2-inch diameter drill, enlarge hole in outer panel, drilling from outside of door.
  5. Insert handle assembly and place escutcheon plate against door panel; with holes in vertical position drill 2 holes 3/16-inch diameter.
  6. Remove handle and escutcheon.
  7. Enlarge the two 3/16-inch holes by redrilling to 29/64-inch diameter.
  8. Remove lock.
  9. Insert reinforcement A-35634 and line up with three holes now drilled in outer panel.
  10. Insert two clinch on nuts A-21573 through holes in panel and reinforcement and peen over on outside panel.
  11. Assemble lock, placing all screws in place.
  12. Place pad A-35630 under escutcheon and insert shank through dog and apply two screws A-20214.
  13. Place washer A-22308 on inside of door against cardboard and place handle A-35632 on end of square shank and fasten on with screw A-20212.

Carburetor Choke Lever

The carburetor choke lever has been redesigned to permit easy choking when cranking the engine by hand. This change consists of adding a hole at the end of the lever (see “A,” Fig. 609) so that a wire or piece of twine can be easily attached for choking.

((609))

Transmission Shaft and Gears Held to Closer Limits

The intermediate and high sliding gear and the low and reverse sliding gear are now fitted to exceptionally close limits on the trans- mission main shaft. In addition the parts are selectively assembled. This procedure insures extremely accurate fitting and it eliminates any possibility of the gears coming out of mesh. The new dimensions of these parts are as follows:

((610))

Transmission main shaft A-7061 (See “D,” Fig 610) changed outside diameter from 1.2465/12475 to 1.2485/1.249 Width of splines (See “W,” Fig. 610) changed from .3095/.3115 to .308/.309.

Transmission low and reverse sliding gear A-7100 and transmission high and intermediate sliding gear A-7101, the large diameter of the splined hole in these parts has been changed from 1.2490/1.2505 to 1.2495/1.2505.

Due to the close limits to which these parts are held it will be necessary when installing new shaft and gears to assemble the parts by selective fit.

Installation of A-11350 Special Replacement Starter (Bendix) Drive

Installation of A-11350 Special Replacement Starter (Bendix) Drive

On Model “A” cars and trucks in production since early October, 1928, the A-11350-C 8/10 pitch bendix drive has been used. For this drive the starting motor armature shaft has a diameter of 5/8-inch. This drive has a special form of ten tooth pinion and we call your attention to the fact that it is not inter- changeable with the standard 8/10 pitch ten tooth pinion T-1883.

Complete starting motors, as now used on Model ” A ” production since October 1st, 1928, can not be assembled on cars and trucks produced prior to October 1st, because of the change in the flywheel. Present starting motors with the 11350-C drive can only be used with the present design of flywheel.

Dealers who are reworking armature shafts for installing special bendix drive A-11350 must use especial care in performing this important operation. Recently some cases of broken armature shafts have been reported. Investigation in each instance showed that no radius had been left at the 4 1/2-inch line (see Fig. 611).

The following instructions have been care- fully worked out and must be closely followed :

Installation Instructions

The A-11350-DR bendix drive is a special type for replacing the Abell starter drive used on Model “A” cars and trucks manufactured previous to October, 1928. Its installation requires reoperation of the armature shaft and of the end bearing of the starting motor; for that reason the following instructions should be closely followed. There are two types of Ford Model “A” starting motors on which this 11350-DR drive can be mounted, the first type having a ball bearing in the starting motor end plate and the second a plain bear- ing. Ball bearing equipped starting motors can be easily distinguished from the plain bearing type by noting the ball beating retainer plate which is bolted to the end plate. The reoperation of these two starting motors for installation of the 11350-DR drive is slightly different as noted on next page.

((611))

  1. Remove armature from starting motor and withdraw bearing from armature shaft — bearing can be forced off by dropping the end of the armature shaft on a lead block.
  2. Before turning down armature shaft make certain it is not bent—if any such condition is shown when the shaft is indicated on centers, shaft should be straightened before starting reoperation.
  3. The file-hard surface of the portion to be turned down can be ground off, thus making the turning operation much easier.
  4. With the armature mounted in a lathe, turn down the enlarged portion of the shaft to a diameter of .494—.498 or flush with exist- ing diameter a t the outer end, and back to a point exactly 4 1/2 inches from the center of the pilot screw hole in the armature shaft (see Fig. 611). Note 1/32-inch to 1/16-inch radius at the shoulder as shown below and described later. Do not try to remove all the metal in one cut, also make the last cut a very light one; this helps to obtain the correct diameter and to keep the surface as smooth as possible. The turned down diameter should merge into the similar existing diameter at the outer end without leaving any shoulder or tool marks of any kind at the point where the turning started.
  5. In completing the turning operation care must be exercised not to mar the surface of the shaft back of the 41/2-inch line, inasmuch as this is the bearing portion of the armature shaft. Leave a radius of between 1/32-inch and 1/16-inch at the 4 1/2-inch line where the larger diameter merges into the newly turned diameter (see Fig. 611). Do not leave a sharp tool mark at this point and avoid any under- cutting of the shaft because this results in possible breakage of the shaft at any such weak point. The radius is of special importance, inasmuch as it strengthens the shaft at the point of the change in diameter
  6. After completing the turning operation smooth the newly turned diameter by a light touch with a file with the shaft turning in a lathe.
  7. Before reassembling armature shaft remove all chips and dirt which may have wedged in between the armature wires—re-assemble the ball bearing up against the shoulder on the armature shaft and make sure it is well packed with lubricant.
  8. In assembling the motor use a new ball bearing retainer plate, part No. A-11133-R, or bore out the present plate to a diameter of 1 r^-inch so that the stop nut on the end of the bendix drive can pass through this retainer plate (see fig. 612)
  9. Before assembling the bendix drive on the starting motor, rub a little grease or oil on the armature shaft so as to prevent any rusting between the bendix shaft and the armature shaft. Do not place any lubricant on the screw threads on the shaft. When assembled, the stop nut of the bendix drive should be against the shoulder on the armature shaft at the 4 1/2-inch line, but in assembling the drive it should not be necessary to compress the spring more than 1/16-inch. If you must compress the spring more than 1/16-inch to insert the spring screw pilot end into the armature shaft, you will find one of the following conditions present: (a) The 4 1/2-inch dimension on the armature shaft is undersize, (b) the ball bearing end plate has not been replaced or the hole bored larger or, (c) in case the starting motor is of the plain bearing type, additional metal should probably be removed from the bearing boss (as described later). When the bendix drive has been completely assembled, compress the gear and shaft portion backward, then release it and make certain the drive freely resumes its original position. An armature shaft diameter of over .498-inch or a bent shaft restricts the free sliding movement of the gear and shaft portion of the drive on the armature shaft and this results in failure to mesh and damage to the pinion and flywheel gears.
  10. In assembling the bendix drive, make certain that the two logs on the end of the head portion fit into the slot of the sleeve portion—turn down the head screw until it holds the spring tightly in place and bend up the lip of the lock washer against a a flat side of the head of the screw (See Fig. 614). A new Woodfruff key, No. 5 should be used if the old one is sheared or damaged. In assembly of the head portion, make certain the Woodruff key fits into the keyway slot of the head and that the key is not pushed forward into the space between the head and sleeve. With no Woodruff Key connection between the bendix drive head and the armature shaft the driving torque is transferred to the pilot of the screw which will soon shear under such conditions.

((612 + 613 + 614))

Installation of Plain Bearing Starting Motors

Follow the same instructions listed in para- graphs Nos. 2, 3, 4, 5, 6, 7, and 10, omitting No. 1, and substitute the following for No. 8 paragraph:

The face of the plain bearing or boss portion of the starting motor end plate must be cut back a distance of 9/64-inch in order to provide the necessary space for the assembly of the replacement drive. It is best to do this operation in a lathe, being careful after completing it to remove any burr which might have been thrown into the bearing itself. Note Fig. 613 showing that the distance between the mounting face of the end plate and the end of the boss must be 11/64-inch after completing the facing operation.

In reassembling the starting motor on the engine, remove any shims which may have been used between the starting motor flange and the flange on the flywheel housing.

Before installing, the starting motor, the flywheel ring gear teeth should be carefully inspected. It is of course difficult to note the meshing or back end of the teeth from the starting motor hole, but with the aid of a mirror this can be accomplished. If the flywheel teeth are badly damaged, a new ring gear should be installed. Meshing of the pinion gear takes place at two opposite points on the flywheel ring gear and if the teeth at these points are only slightly burred, the worst of these burrs can probably be removed by using a small file—any filing should be in the same direction as the original chamfer and no chamfer should be filed on the side of the tooth originally left unchamfered.

It has been called to our attention that some dealers are attempting to replace the former starter drives on the Model “A” by reoperating the T-1883 type bendix as used on the Ford, Model “T,” or in some cases reoperating other type bendix drives We have noted the results of this attempted reoperation in several instances and wish to advise that the reoperation of any such type bendix for use on the Model “A” car is not only inadvisable but must be discontinued at once

Windshield Wiper Installation on Open Cars

Several changes have been made in the electric windshield wiper for open cars. These changes slightly alter the installation instructions contained in the May Bulletin.

When installing the present electric wiper on open cars, it will be necessary to drill a 1/4-inch hole on the inside of the windshield support 3 1/2 inches below the centerline of the windshield wing nut. This 3 1/2-inch dimension must be observed to avoid conflicting with the installation of windshield wings.

With the exception of these changes the windshield wiper instructions contained in the May Bulletin apply to the present wiper.

Breaker Arm Assembly

((588))

As an added protection against car theft, the distributor breaker arm spring is now riveted

around the breaker arm spring stud (see A, Fig. 588), the thickness of the head of the stud increased and the stud case hardened.

These changes add two more parts to the breaker arm assembly, namely, breaker arm spring A-12169 and breaker arm spring stud A-12157.

To install the new breaker arm assembly, it is necessary to remove the breaker plate assembly. This, of course, will necessitate retiming the ignition.

Installing Piston Pins

((618))

Under no circumstances should a hammer be used on the piston pin pilot and driver when installing a piston pin. Immersing the piston in boiling water for a minute or two will expand the piston pin hole sufficiently to permit easy installation.

To correctly install pin first insert the piston pin pilot and driver through piston pin hole as shown in Fig. 618, then place pin over end of pilot (see Fig. 619) and push piston pin into place.

((619))

Engine Cylinder Head Nuts

A blown out cylinder head gasket can invariably be traced to failure to securely tighten cylinder head nuts, particularly during the first 50 miles a new car is driven. During this period the new cylinder head gasket becomes slightly compressed, as a result all of the cylinder head nuts can be taken up several times until the gasket obtains a permanent set. This also applies when a new cylinder head gasket is installed in an old car.

After completing a drive-away trip, instruct your mechanics to go over all of the cylinder head nuts and see that they are securely tightened. An additional check should also be made before delivering the new car to the owner, and again when the car is brought in for inspection.

The nuts should be tightened with the engine thoroughly warmed up. When tighten- ing the nuts it is of course understood that excessive force should not be applied, as there would be a possibility of damaging either a stud or nut.