TM 9-1829A Maintenance Manual Download Page 88 | Manualshive

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TM 9-1829A Maintenance Manual Download Page 88

TM 9-1829A, April 1944

88/100

2021-07-07

Chapter 10: AC speed adapters

53. Function

a.

Ordinarily the vehicle manufacturer compensates for variations in tire size and rear axle ratio by the
installation of corresponding speedometer drive and driven gears in the transmission. However, in some cases
a speed adapter installation is desirable to eliminate special gear cutting or to achieve greater speedometer
accuracy. In some cases, 1:1 ratio right angle adapters are used at the transmission to avoid a sharp bend in
the flexible shaft.

Figure 134: AC heavy-duty speed adapter

54. Application

a.

It is sometimes necessary to make service installations of speed adapters to compensate for changes made in
rear axle ratio or tire size. See speed adapter chart for various ratio adapters, selecting the ratio closest to
whatever is required. The following information is required to figure the correct speed adapter ratio:
(1)

Tire outside diameter.

(2)

Rear axle ratio.

(3)

Number of teeth in transmission speedometer drive and driven gears.

55. Disassembly, repair, and assembly

a.

Generally, it is not economical to repair a speed adapter when more than one of the gears or the housing is
damaged. Straighten tangs on bearing plug lock washer. Remove two bearing plugs which will allow
disassembly of lock washer, drive gear (shaft bearing greatest O.D. 0.369 inch) and driven gear (shaft bearing
greatest O.D. 0.340 inch). The drive gear shaft may be pressed out for separate replacement of shaft or gear.
One bearing plug has an Alemite fitting and the other a grease pressure relief valve. The valve is set to relieve
grease pressure in excess of 5 pounds per square inch and must always be assembled opposite flexible shaft
take-off or male threaded end. Do not disassemble the bushings at each end of the body die casting. Assembly
is the reverse of disassembly. If gears are assembled on their respective shafts care must be taken to keep
shaft square with gear while pressing together.

Figure 135: AC heavy-duty speed adapter, disassembled

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Summary of Contents for 9-1829A

Page 1: ...TM 9 1829A April 1944 1 100 2021 07 07 TM 9 1829A War department Ordnance Maintenance Speedometers Tachometers and Recorders...

Page 2: ...s 34 19 Description 34 20 Disassembly 35 21 Cleaning inspection and repair of parts 37 22 Assembly 37 Chapter 5 King Seeley speedometer 38 24 Disassembly 38 25 Cleaning inspection and repair of parts...

Page 3: ...pter 11 Stewart Warner drive joints 89 Section I 666 type drive joints 89 56 Description 89 57 Operation 90 58 Disassembly 90 59 Cleaning and inspection 91 60 Assembly 92 Section II 659 type drive joi...

Page 4: ...T 170654 25 Figure 30 Stacking intermediate gear using fixture T 178717 26 Figure 31 Pressing collar on magnet shaft using fixture T 170666 with Det 1 27 Figure 32 Flaring magnet shaft using fixture...

Page 5: ...gure 82 Drilling out crimping at center of spur gear 59 Figure 83 Speedometer mechanism odometer frame removed 59 Figure 84 Removing hair spring using puller T 66296 60 Figure 85 Removing second gear...

Page 6: ...pter disassembled 88 Figure 136 Stewart warner type 666 drive joint 89 Figure 137 Stewart Warner type 666 drive joint disassembled 89 Figure 138 Removing gear A using adapter tool T 178708 Det 4 90 Fi...

Page 7: ...these parts are not attached to the speedometer itself 1 Speedometer A speedometer fig 1 is used to indicate vehicle speed in miles per hour as shown by the pointer and face dial and to record distan...

Page 8: ...TM 9 1829A April 1944 8 100 2021 07 07 Figure 2 Speedometer installation Figure 3 Flexible shaft Figure 4 Tachometer...

Page 9: ...exerts a pull or magnetic drag on the speed cup making it revolve in the same direction The movement of the speed cup is retarded and held steady by a hair spring attached to the speed cup staff The s...

Page 10: ...ves an intermediate second gear and third gear which is connected to a fourth gear at the odometer The fourth gear turns the odometer through a series of star pinion gears inside the odometer dials or...

Page 11: ...roper chapter of this manual may be referred to for instructions b Methods of identifying instrument manufacturer 1 AC Company name AC Spark Plug Flint Michigan stamped on rear of case fig 9 A part nu...

Page 12: ...6 5 Waltham chapter 7 Refer to applicable chapter for detailed tests which in some cases are special to each make of instrument b Test for tight mechanism First check to determine whether or not the...

Page 13: ...information on each make instrument refer to applicable chapter 1 Pointer fluctuates or wavers a Broken worn dry or dirty front or rear jewel Replace clean or lubricate jewels according to manufacture...

Page 14: ...Odometer bound up Replace complete odometer assembly Do not attempt to repair unless so specified in this manual e Odometer intermediate gear turning on shaft Stewart Warner only Restake gear on shaf...

Page 15: ...frame is also used Further some speedometers are supplied without reset type odometers known as tripless types Some units are equipped with solid reset shafts while others use flexible reset shafts A...

Page 16: ...TM 9 1829A April 1944 16 100 2021 07 07 Figure 16 AC tachometer disassembled Figure 17 Speedometer mechanism dial removed...

Page 17: ...frame and lift the clip upward Push the odometer shaft out with short piece of wire or rod Centralize the short rod in the frame and lift the odometer out as a unit f Remove odometer quick reset trip...

Page 18: ...of frame otherwise frame bearing will be scratched beyond repair Do not touch end of frame with file as this is a thrust bearing surface m Remove intermediate gear perform this operation only if gear...

Page 19: ...ng end is too short to form an adequate flare over the retaining collar Replace magnet if the speed cup staff bearing is rough or if the bearing causes the speed cup to drag Note See calibration par 9...

Page 20: ...gear with No 00 grease O D and install in main frame Helical gear meshes with worm of second gear g Install front jewel and bracket assembly Place small composition thrust washer over upper end of spe...

Page 21: ...h small wooden handled screwdriver to secure in position m Calibration The speedometer or tachometer should be calibrated at this stage of the assembly procedure par 9 n Install case bezel and glass I...

Page 22: ...head speed of 30 miles per hour Demagnetize by holding one pole of the magnetizer near the field plate and press button immediately releasing it When this is done it may be well to hold one finger be...

Page 23: ...then remove glass and dial b Remove case Remove two screws and lock washers from back of case and lift out main frame assembly Do not lose dust washer between main frame and case c Remove pointer Rem...

Page 24: ...With screwdriver remove two screws and lock washers and lift field plate and speed cup from main frame i Remove third gear Lift third gear from its bushing being careful not to lose any thrust washers...

Page 25: ...any kind such as small cracks or rough bearing surface be sure all threads are in good condition if necessary insert screws to test Check for being out of line and make sure locating pins are in good...

Page 26: ...ears turn freely Figure 30 Stacking intermediate gear using fixture T 178717 b Install magnet Place thrust washer on shaft of magnet apply slight amount of watch and clock oil on washer and magnet sha...

Page 27: ...emble front jewel bracket fig 33 Place front jewel in bracket and screw in until lower end is even with under side of bracket Place hair spring regulator over top of jewel with anchor end toward third...

Page 28: ...odometer fig 25 par 11 e Place clutch spring over odometer gear and clutch assembly Put clutch on odometer shaft and engage clutch in odometer hub Note Care must be taken so that alinement of odomete...

Page 29: ...arging magnet using Magnetizer 846294 c Demagnetizing and calibration chapter 13 1 When the speedometer is magnetized so that a speed of at least 70 miles per hour is indicated when master head indica...

Page 30: ...per hour against the stop d Test data 1 Index Part no Test no SPA 4026 1 SPA 4040 2 SPJ 4001 1 SPJ 4004 2 SPK 4001 3 SPK 4001A 3 SPK 4001B 3 SPK 4002 3 SPL 4001 1 SPM 4003 2 SPP 4001 4 SPR 4001 3 2 Te...

Page 31: ...e Remove odometer fig 39 Remove odometer spacing clip with pliers grip flange of odometer shaft bushing with pliers and move bushing toward odometer figure wheels then move same end of shaft forward...

Page 32: ...earing surfaces and teeth with No 00 grease O D Place thrust washer on inner end of shaft and insert gear in main frame Place outer bushing on shaft of gear with beveled side in and press second gear...

Page 33: ...e made to lie flat and have uniform spacing of coils Note It is very important that this adjustment be properly made i Install odometer fig 39 Aline pinion carriers for proper engagement with jewel br...

Page 34: ...edometer fig 37 is a single magnet type with the hair spring mounted above the front jewel bracket odometer mounted above center of dial trip odometer below center of dial and with revolving field pla...

Page 35: ...at same time pulling odometer pinion carriers from front jewel bracket until they clear bracket Repeat to remove trip odometer g Remove hair spring fig 39 1 Place one nose of pliers against small end...

Page 36: ...ition or if side play exceeds 0 003 inch install puller on frame and screw plunger against magnet shaft until shaft is free of collar fig 42 Remove collar and file burs from shaft Caution Do not drive...

Page 37: ...tion with hammer and drift Check end play of second gear and install thrust washers if necessary to get 0 005 to 0 010 inch end play Stake frame over bushing at three equally spaced places around bush...

Page 38: ...ll bezel off fig 52 and remove gaskets glass and glass retainer Remove reset knob screw reset knob reset spring and washer If knob is tight hold both reset shaft and reset knob with small pliers and t...

Page 39: ...with tweezers Carefully remove hair spring from staff with special puller T 66296 fig 46 Figure 46 Removing hair spring using Puller T 66296 e Remove front jewel bracket speed cup and third gear Remo...

Page 40: ...requires frame replacement If the second gear bushing the field plate or the intermediate gear are worn or missing replace the entire frame assembly c Magnet Inspect first gear If visibly worn or nic...

Page 41: ...care that staff locates properly in the magnet bearing Place small bakelite thrust washer over end of staff Apply light coat of No 00 grease O D to teeth of third gear and place gear in position prop...

Page 42: ...by turning counterclockwise until the pointer indicates zero with the speed cup against the stop pressing slightly downward Check hair spring tension If pointer returns too sharply to zero or too slo...

Page 43: ...graphs 2 and 4 Figure 50 Stewart Warner speedometer with cup type magnet disassembled 29 Disassembly a Remove bezel and case 1 Crimped bezel Pry up bezel at crimped points with screwdriver and remove...

Page 44: ...until it is forced loose from staff fig 53 Then remove two dial retaining screws and lift off dial Figure 53 Removing disk type pointer using special puller T 131105 c Remove odometer assemblies Ther...

Page 45: ...eed cup fig 56 Remove rear jewel bracket screw and lift out bracket Remove the two front jewel bracket screws and lift out speed cup front jewel bracket and hair spring as an assembly Figure 56 Speedo...

Page 46: ...spring using puller T 66296 f Remove front jewel and hair spring regulator fig 59 Using 1 4 inch open end wrench T 185488 remove front jewel nut and hair spring regulator Unscrew front jewel from bra...

Page 47: ...be taken when using fixture to make sure that it does not come in contact with steel portion of magnet causing it to be weakened Figure 61 Smoothing out flare in magnet shaft using fixture T 170666 wi...

Page 48: ...y dry parts with compressed air Wipe other parts clean with a rag b Front and rear jewels Sharpen a match or orange stick to a fine point and use for cleaning jewels Using jeweler s eyepiece inspect j...

Page 49: ...nd calibration a Replace odometer intermediate gear assembly Place washer over odometer drive gear shaft and place shaft through frame with drive gear on inside Place another washer over shaft outside...

Page 50: ...9 Screw front jewel into bracket Place hair spring regulator in position and screw on front jewel nut but do not tighten Place tiny thrust washer over end of speed cup staff and place speed cup and st...

Page 51: ...AF 197 579 AB 161 590 AJ 234 581 B 65 590 AM 235 589 D 245 Figure 69 Magnet strength tester 408165 on frame and magnet assembly attached to calibrating machine T 170645 Pointer deflection in degrees a...

Page 52: ...ame Insert rear jewel bracket and fasten in place Then fasten upper jewel bracket in place Test speed cup for free turning and end play i Replace hair spring pin and aline hair spring Insert end of ha...

Page 53: ...ng clip fits over end of shaft If a new odometer is used it may be necessary to line up the figure wheels as the shaft lug on the new odometer may be in a different position than the lug on the old od...

Page 54: ...t be installed to eliminate slow ness If this does not correct slowness magnet is too weak and must be replaced Run master at 10 miles per hour again and make any necessary minor corrections in instru...

Page 55: ...acing upper die of Bezel rolling fixture T 178730 over speedometer Figure 75 Rolling bezel with fixture T 178730 in arbor press 3 Attach miscellaneous parts to speedometer such as reset shaft nut rese...

Page 56: ...9 702 721 722 727 733 751 752 757 833 851 852 32 Description This type instrument fig 76 operates on same principles as all other makes and types of magnetic units However it can readily be identified...

Page 57: ...ezel remover T 42358 drive bezel off fig 77 Figure 77 Driving off pressed on bezel using remover T 42358 b Remove pointer and face dial On instruments where dial reads clockwise remove pointer by gras...

Page 58: ...80 Figure 80 Removing bevel gear and sleeve assembly using spanner wrench T 49509 d Remove odometer assemblies Remove three screws fig 99 and lift off complete odometer and frame assembly This allows...

Page 59: ...ove two screws fig 83 and lift out rear jewel bracket Figure 83 Speedometer mechanism odometer frame removed Place one jaw of long nosed pliers against shoulder that holds hair spring pin and other ja...

Page 60: ...moving hair spring using puller T 66296 g Remove second gear Place frame gear and magnet assembly in vise not too tightly Using punch drive on end of second gear fig 85 until brass bushing at other en...

Page 61: ...hen turn wrench handle clockwise fig 86 until collar is pressed off the magnet shaft Figure 86 Removing magnet shaft collar using dismantling wrench T 170654 Push magnet back to original position and...

Page 62: ...t wick out of frame using tweezers 34 Cleaning inspection and repair of parts a General The cleaning inspection and repair of these type instruments is the same as for Stewart Warner speedometers with...

Page 63: ...of magnet causing it to be weakened Figure 90 Pressing collar on magnet shaft using fixture T 170666 with Det 1 Figure 91 Pressing bevel gear on magnet shaft using fixture T 170666 with Det 1 Using fi...

Page 64: ...ar bushing in place d Test magnet strength to determine proper hair spring Place hair spring selector 408164 on frame and magnet assembly Place assembly on calibrating machine fig 94 and run master at...

Page 65: ...nterclockwise face dial then the loose end of the hair spring should point in a clockwise direction Using female punch T 29 Det 2 carefully drive hair spring on staff leaving about 1 8 inch clearance...

Page 66: ...pring protruding through slot about 1 8 inch Figure 96 Adjusting front jewel using special tool T 178705 Using long nosed pliers squeeze pin tightly in position fig 97 with small end of pin pointing i...

Page 67: ...nvil of staking fixture T 178717 Det 4 and using a female punch drive spur gear as far as it will go on shaft Using staking tool T 178717 Det 3 stake inside end of drive gear shaft securely fig 98 Che...

Page 68: ...sleeve fig 80 and lightly dress down the face of the brass sleeve with a file until a closer meshing of gear teeth is obtained i Calibrate Hold dial in position and press pointer lightly on staff at...

Page 69: ...within limits below by moving hair spring regulator fig 83 or by moving the magnet regulator as follows Remove hole plug at back of case using adjusting kit T 178715 to catch on magnet regulator Place...

Page 70: ...aximum hand which automatically locks at the maximum speed revolutions per minute at which the engine is operated The maximum hand locking device is usually sealed so that vehicle operator cannot rele...

Page 71: ...s is done by using a short piece of inner core 3 to 4 inches long with proper tip to fit the drive position at neck of instrument being tested fig 14 If tightness or binding is apparent it is caused b...

Page 72: ...and maximum hand assembly Figure 106 Removing pointer using lifter T 29 Det 3 c Remove pointer mechanism Remove maximum hand reset lever spring fig 107 Remove two screws fig 107 and lift out pointer m...

Page 73: ...ke barely audible sound when this is done and should hold maximum hand in position until manually released allowing coil spring to return maximum hand counterclockwise to pointer stop If tension is to...

Page 74: ...e Tighten down upper ball race fig 109 allowing about 0 002 inch end play in governor shaft While holding upper ball race with screwdriver tighten lock nut securely fig 108 Place special screwdriver T...

Page 75: ...volutions per minute difference is necessary to offset the drag of the maximum hand Run master at 1 800 revolutions per minute Indicating pointer of unit being calibrated should read 1 850 revolutions...

Page 76: ...hen pull bezel off fig 52 and remove gaskets glass and retainer Remove reset knob press fit and lift off reset spring and washers Remove two case screws at back and lift out mechanism b Remove pointer...

Page 77: ...lug Hold in this position and adjust hair spring using tweezers until coils are equidistant from each other and parallel to the bonnet At no point of swing should the coils touch each other To adjust...

Page 78: ...p odometer shaft and place assembly in frame Place dial supports in position over locating pins making sure that upper end of third gear fits in hole in right hand support and that hair spring regulat...

Page 79: ...et adjusting screws with calibration adjuster STS 10878 f Replace case glass bezel etc Place mechanism in case and fasten two screws Place glass retainer glass gaskets and bezel in position and roll b...

Page 80: ...t the left end of the recorder for attaching the flexible shaft A male threaded sleeve is provided at the right end for connecting a flexible shaft leading to a tachometer where desired Figure 118 Ste...

Page 81: ...r dials or figure wheels As any one wheel finishes a complete revolution it turns the next figure wheel to the left 1 10 of a revolution 47 Disassembly a Remove odometer and driven gear fig 120 Remove...

Page 82: ...excessive wear and defects Wipe odometer figure wheels clean but do not wash odometer in dry cleaning solvent as this will remove lubricant Inspect for free movement of figure wheels and see that gear...

Page 83: ...y the ferrules and nuts 52 Repair of flexible shafts a Inner core Pull old core out of casing Check removed unbroken core for kinks by rolling on a flat surface If a flat surface is not available take...

Page 84: ...any burs on end of core stock Note Never cut new core to longer length than old core However new core may be slightly shorter than old core Figure 126 Cutting core stock using fixture T 136374 3 Make...

Page 85: ...ld core firmly and using heavy hammer strike hard blow on fixture Repeat crimping operation with tip in different position Remove from die and test for firm crimp Squaring and tip crimping require ext...

Page 86: ...asing stock and using hacksaw carefully cut off proper length for casing being made up Grind off any burs on ends of casing stock 3 Attach ferrules Using old casing assembly as a guide insert new casi...

Page 87: ...ing as described above Figure 132 Crimping ferrule using pliers T 122308 c Assemble flexible shaft Spread a thin coat of No 00 grease O D evenly over lower two thirds of core only This is best done by...

Page 88: ...ratio 1 Tire outside diameter 2 Rear axle ratio 3 Number of teeth in transmission speedometer drive and driven gears 55 Disassembly repair and assembly a Generally it is not economical to repair a spe...

Page 89: ...6 type drive joint sometimes known as an adapter consists of a train of four gears inside a die cast box figs 136 and 137 Threaded sleeves are provided for connecting the drive joint to the power take...

Page 90: ...case Take out four screws holding case together pull case apart and lift out intermediate gear assembly B and C fig 137 Mark intermediate gear assembly so that it is assembled in same position b Remov...

Page 91: ...embly unless gears are worn or defective If taken apart a new intermediate gear shaft must be used when the parts are assembled Place special tool T 178708 Det 1 and intermediate gear assembly in vise...

Page 92: ...diate shaft and press gear B on opposite end of shaft until it is flush against gear C fig 142 The two gears should now be centered on the shaft so that dimensions are as shown in figure 144 Figure 14...

Page 93: ...inside of case making sure that slot in sleeve lines up with pin hole in case Using small hammer drive pin in place Figure 147 Pressing sleeve transmission end into case using adapter tool T 178708 D...

Page 94: ...or head and its drive and merely transmits power from the distributor drive to the flexible shaft leading to the instrument 63 Repair The only parts of this type adapter that would normally require se...

Page 95: ...ront jewel T 178705 153 D Adjuster hairspring T 51742 153 E Adjuster magnet regulator T 178715 154 A Crimper flexible shaft ferrule T 52644 153 F Extractor gear ST 263 34 154 B Fixture bezel rolling T...

Page 96: ...66296 153 P Remover pressed on bezel T 42358 152 I Shaft flexible extension for 0 104 in female drive 95000 72 in 152 J Shaft flexible extension for 0 104 in square male drive 97800 72 in 152 K Shaft...

Page 97: ...TM 9 1829A April 1944 97 100 2021 07 07 Figure 153 Special tools Figure 154 Special tools...

Page 98: ...60 miles per hour at 2 000 revolutions per minute as mentioned above In addition to the master head a stroboscope is provided for checking master at 30 60 and 90 miles per hour Any errors in the maste...

Page 99: ...er between the field plate and the pole presented to it thus preventing the magnetizer and demagnetizer tool from being pulled into contact with the field plate and completely discharging the magnet F...

Page 100: ...1 Tools maintenance for repair of automotive vehicles SNL G27 Tool sets motor transports SNL N19 Explanatory publications General List of publications for training FM 21 6 Military motor vehicles AR 8...

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