servicing instructions and illustrated parts list for hewland egt… · 2014. 1. 6. · the egt...

© Copyright Hewland Engineering Limited 2012

SERVICING INSTRUCTIONS AND ILLUSTRATED PARTS LIST FOR HEWLAND EGT/WGT

GEARBOXES

HEWLAND ENGINEERING LTD WALTHAM ROAD, WHITE WALTHAM,

MAIDENHEAD,BERKSHIRE, SL6 3LR,ENGLAND


Page Page Technical specification 4 WGT Internals 27 General notes 5 Inverted Dog Kit 28 Sequential Barrel Setting 6 Optional Oil Pump Kit 29 Gearbox Assembly 7 Optional Tripod Gaitor 30 Changing Gear Ratios 12 Gearbox Tooling 31 Powerflow Differential 13 Ratio Chart 32 Powerflow Set-up 14 Technical Bulletins 33 Illustrated Parts List 15 Manual Modifications 47

CONTENTS


page page Fig.1 Sequential Barrel setting 6 Fig.12 4 Planet Diff Option

20

Fig.2 Reverse idler assembly 7 Fig.12 Selector barrel assembly 22

Fig.3/4 Mainshaft preload 8 Fig.13 Ratio cluster assembly 23

Fig.5 Selection mechanism section 9 Fig.14 Slave cylinder assembly 24

Fig.6 Reverse selector fork assembly 10 Fig.15 WGT wide ratio parts 27

Fig.7 Neutral lockout assembly 11 Fig.16 Inverted Dog Rings 28

Fig.8 Powerflow diff preload 14 Fig.17 Optional Oil Pump Kit 29

Fig.9 Powerflow diff assembly 16 Fig.18 Optional Tripod Gaitor 30

Fig.10 Adjustable Powerflow diff assembly

17 Fig.19 Gearbox tooling 31

Fig.10a Oil system for Adjustable Diff

18 Fig.20 Ratio chart 32

Fig.11 3 Planet Diff Option

19

ILLUSTRATIONS


TECHNICAL SPECIFICATION The EGT gearbox is designed for front engined, front wheel drive cars, with two litre engines. The unit is produced with six forward gears and reverse. A powerflow differential is fitted as standard. The gear selection mechanism is sequential, with a separate, mechanically interlocked reverse engagement mechanism. The drive is taken from the engine via the clutch shaft, which turns input and pinion gears to drive the final transmission assembly. Gear changing is effected through non-synchronising face dogs. An extensive range of gear ratios provides an excellent range of gearing requirements. The gear Ratios and differential assembly can easily be changed without removing the gearbox from the vehicle. (Subject to installation restrictions) Heat treated nickel chrome steel is used to manufacture all gears and shafts. The selector forks are also steel. Standard gearbox is splash lubricated. An optional internal oil pump is available and the oil is retained by lipped oil seals. In general configuration, the EGT is a high tech racing transverse unit which achieves the maximum effective use of power. From 2011, a variant known as the WGT has been introduced. This has increased torque capacity courtesy of wider gear ratios (1st - 4th) specifically developed for the introduction of turbo engines in various Touring Cars series. Weight 73 lbs (33 Kg) Gear ratios from 3.31:1 to 0.89:1 Oil type SAE 80 or 90 Final drive ratios 3.6 standard (other ratios available on request) Oil quantity 1.75 pints (1 litre) Clutch shaft made to customer's requirements (with oil pump) Max. torque EGT = 320 lbs.ft (430 Nm) WGT = 348 lbs.ft (470 Nm)


GENERAL NOTES a/ Read these instructions carefully and with reference to the illustrations. b/ Before dismantling the gearbox, see that a clean tray is available, in which to place the parts. c/ Thoroughly clean and inspect all parts before reassembly. Discard any worn or damaged components and replace

with new ones. d/ Use only genuine Hewland parts as replacements. These are manufactured in our workshops to the fine tolerances

necessary and are rigorously inspected. e/ Always use new nuts, circlips and oil seals when reassembling. f/ All studs and screws must be Loctited or wirelocked in position, unless stated otherwise g/ Bearing Replacement :- Bearings can only be removed or renewed if the casings have been warmed in an oven (120°C), or with a

blowlamp. In the latter case, keep the blowlamp moving while heating the casing. Note: Do not overheat. Test with a spot of water which will bounce off at the correct temperature. Once a casing is heated, all bearings should be pressed into their respective seatings without delay, thus eliminating

the need to reheat. At the correct temperature, fitting the bearings should present no difficulty. When the casings have cooled, it is advisable to once more lightly press the bearings to ensure that they are

correctly seated. h/ Oil: Fill the gearbox through the plug hole on top of the bearing carrier. The oil will find it's own level within the gearbox. Note: Too much oil will not directly cause any harm, but is undesirable as it may induce power loss and overheating

of internals.


Fig. 1

SEQUENTIAL BARREL SETTING a/ Assemble the barrel (47), spacer (116), bearing

retaining plate (104), bearing (15), and nut (115). slide the barrel assembly into the bearing carrier, and secure using screws (69).

b/ Place the roller (17) onto the detent plunger (3), and

insert them into the bearing carrier (32). Add the detent spring (2), bonded seal (67), and detent plug (103).

c/ Slide the selector forks (46) over the barrel (47), and

secure using selector pins (70). For final assembly, Loctite the pins (70) into the forks (46).

d/ Stack the mainshaft assembly in place in the bearing

carrier, including pinion gears (7) and clutch rings (27). e/ Place the complete assembly into the fork setting fixture

SK-1732 f/ Rotate the barrel to engage neutral position. Measure

and record the gap between the dogfaces of third through sixth gears. First, third and fifth gear dog gap measurements will be similar (as will second, fourth and sixth). Any difference between the odd & even gear measurements must be corrected by replacing the barrel spacer (116) with one of the correct thickness.

Note: Individual setting of each fork is not possible (and is not necessary)


Fig. 2

GEARBOX ASSEMBLY a/ It is assumed that all bearings, oil seals, studs, oil jets, and dowels are already fitted into casing. b/ Press bearing (60) into reverse idler gear (42), fit top hat bushes (56,140) into bearing carrier (32). Note which top

hat goes where. Fit inner race sleeve (57) into bearing (60). Place in position. Secure with screw (91).

Reverse Idler Assembly


Fig. 4

c/ Stand the maincase on it's engine end face. Assemble the mainshaft (40), thrust washer (107), hub (106), and hubs (5) into the maincase (30). Measure (dimension 'A', Fig 3) the depth from the end of the maincase to the exposed end of the last hub.

Stand the bearing carrier (32) on it's outboard end. Slide the reverse hub (105) into it's bearing. Measure (dimension

'B', Fig 4) the height of the exposed hub face from the bearing carrier machined face. Subtracting dimension 'B' from dimension 'A' will give the bearing preload. The preload should be set to 0.001”/0.002" (cold). If the bearing preload is incorrect, remove the bearing (14) from

the bearing carrier (32) and adjust the shims accordingly.

Fig. 3


Fig. 5

d/ Position the pawl (51) in the slot in the selector rack (50). Press the pin (28) into place, ensuring that it isn’t left protrud-ing outside the rack outer diameter. Slide the washers (58), spring (97), and sleeve (59) onto the rack, and secure with circlip. Oil liberally, and slide the rack into the maincase. Ensure that the rack is free to slide back and forth in the maincase. Any stiction here may cause shift problems in service. Insert anti-rotation screw (145), and washer (125) into maincase along with breather bolt (95), banjo and washers (129, 128) Press lipseal (75) bronze bush (135) and press complete assembly into diff cap. Fit diff cap to maincse and check rack slides freely in bronze bush.


Fig. 6

e/ Assemble the barrel driver (48), bearing (20) One is inserted into the maincase (30), pins (29). Place o-ring (87) into retaining plate (31). Slide the barrel driver (48) into it's location in the maincase, fit retaining plate and secure with screws (90). To aid fitment of the barrel drive turn the maincase upside down. This means that the pawl will fall away as not to cause an obstruction to inserting the barrel driver

f/ Fit pawl spring (4) , plunger (94), washer (58) and circlip. Then fit rack stop o-ring and circlip. g/ Build the selector barrel parts into the bearing carrier as described in the section 'Sequential Barrel Setting'. See Fig. 1 on page 6 i/ Hold the reverse selector fork (45), with reverse pinion gear (109) and shim (nominal .020”) (52), in position in the

bearing carrier (32). Slide the reverse selector shaft (44) into place and secure with screw (90). Fit plug (62) with washer (67). Slide spring (141) onto shaft.


k/ With the bearing carrier face up, add the layshaft (110), input gears (9), disc spring (12), and spacers (8). Stack the reverse hub (105), hubs (5,106), pinion gears (7), bearings (6), clutch rings (27), and spacer (107) into position in the bearing carrier (32), and slide the mainshaft (40) into engagement.

l/ Fit neutral blocker. m/ Make sure that the ‘D’ shape on the barrel driver lines up with the selector barrel, then slide the completed gear

cluster assembly into the maincase to engage the shaft bearings. Whilst locating the gear cluster, lightly operate the selector rack (50) to ensure correct location of the barrel and driver.

n/ Lower the differential assembly into the maincase, and secure the diff cover with the nuts (77,79). o/ Slide the clutch shaft (43) into engagement with the layshaft (110). p/ Fit the o'ring seals (83,84) to the slave cylinder pis ton (114). Fit the o'ring seal (82) to the inner sleeve (113). Fit the o'ring seals (85) into the outer cylinder (112). Push the whole assembly into the main case (30), and secure with screws (93). r/ Fit magnetic plug (63), filter plug (62) and washers (67) to maincase.

NEUTRAL LOCKOUT ASSEMBLY

Fig. 7


CHANGING GEAR RATIOS a/ With a drip tray placed beneath the gearbox, remove the drain plug (63) and drain the oil. b/ Disconnect the reverse gear linkage from the gearbox. c/ Remove the M8 nuts (77) securing the bearing carrier (32), and slide it out of the maincase, complete with the gear

cluster. It may be necessary to use the jacking off points (M8 thread), never use a screwdriver to lever between joint faces as this may damage the faces and impair the seal efficiency when reassembled.

Note: The complete gear cluster assembly will slide out of the maincase with the rear casing, leaving the clutch shaft engaged with the engine crankshaft.

d/ Withdraw the mainshaft (40) and remove the pinion gears (7), hubs (5,106), and clutch rings (27). Slide the input

gears (9), and spacers from the layshaft (110), then withdraw the layshaft from the bearing carrier. e/ Replace the gears with the required ratios. Gears are supplied in matched pairs, one for the mainshaft and one for

the layshaft. Each gear is marked with two sets of numbers. The first of these indicates the number of teeth on the layshaft gear, while the second figure signifies the number of teeth on the mainshaft gear which mates with it. Both gears of each pair are marked in an identical manner. It is essential that gears are correctly paired to these numbers.

Note: On all first gears, and some second gears, the gear teeth are machined integral with the layshaft. In such cases, therefore, if a first (or second) gear ratio change is required, the layshaft itself must be changed.

f/ Whilst changing ratios it is advisable, as a matter of course, to wash and inspect all components which are to be

used again before refitting. Check for wear and cracks, particularly to the clutch rings. Also examine the selector forks for heavy or uneven wear.

Note: If any hubs or the mainshaft is replaced, check the mainshaft preload as section ‘c’ of gearbox assembly. g/ Reassembly is the reverse of disassembly. Take care, when refitting the gear cluster into the maincase, to ensure

location of the shafts in their bearings, and of the selector barrel (47) it's driver (48). Note: It is sometimes necessary to slightly rotate either the gear cluster or the differential, to allow alignment of the final drive gear.


3/ The second adjustable factor is how tightly the plate stack is compressed on assembly (known as static preload). Included in the plate stack is a preload spacer. The preload torque is measured between the side bevel gears, by holding one side bevel gear stationary, and measuring the torque required to turn the other using tool SK-838-C. Disc spring provides a pre-load of 100lbs.ft. The static pre-load can be altered by rotating the diff end cap. Each rotation of a tooth alters the pre-load by approximately 20lbs.ft.

4/ The final adjustment is simply to

re-order the plate stack so as to change the number of relatively rotating faces. The diagram shows the stack setup with the maximum 10 working faces. Standard stack may be shuffled to give as few as 2 working faces.

1/ The side bevel gears thrust apart to clamp the plates as they transmit the driving power. This is a feature of the gear geometry, and is not adjustable.

2/ The side ring gears angles

have an effect on how much of the transmitted torque is converted into sideways (clamping) force onto the plates. For example, on the drive side of the ring gear, 45 degrees transmits less sideways force than 30 degrees. Likewise on the coast side of the ring gear, an 80 degree angle will transmit little or no clamping force onto the plates, whereas a 45 degree angle will transmit a much greater force. The side rings gear are available with many different drive/coast ramp angle combinations.

POWERFLOW DIFFERENTIAL This powerflow differential unit is designed with versatility as it's major asset. Many factors will contribute to the settings required. A car with good traction and low power, may require a completely different arrangement to that of a car with poor traction and high power. There are 11 friction plates within the unit (5 splined to the diff casing, and 6 splined to the side bevel gears). Slip limiting is dependant on the friction resistance between these plates, and is affected by clamping the plates together. Four factors contribute to the total friction torque between the plates :-

Fig. 8


POWERFLOW DIFFERENTIAL a/ Place pre-load spacer (A8) into bottom of differential case then clutch and core plates (A7, A11). Then place one half of the ramp pair (A10) into it. Place the side bevel gear (A5) into ramp and then add the planet bevel gears (A9) into the slots in the ramp. Slide the other half of the ramp pair into place (A10) then place remaining plates into the differential case (A7, A11). Place disc spring carrier (A2) on top of the last plate and then screw differential end cap (A4) until tight. b/ Screw in differential end cap (A4) us-ing special tool SK-1731 until you achieve a base pre-load of approximately 20-25lbs/ft for brand new plates using the diff pre load tool SK-838. For bedded in plates this value can be less. Measure the gap between the differential end cap (A4) and the differential case (A1). Make a note of this value. Unscrew the differ-ential end cap. c/ Add a nominal shim of say 0.010” (A12).into the spring carrier (A2) then place the disc spring (A6) on top. Then screw the differential end cap back on and wind it in until you achieve the gap measured earlier. Again measure the pre-load and adjust the shim accordingly to achieve the required pre-load.


ILLUSTRATED PARTS LIST


POWERFLOW DIFFERENTIAL ASSEMBLY (EGT-212)

Fig. 9


ADJUSTABLE PRELOAD POWERFLOW DIFFERENTIAL ASSEMBLY (EGTA-212)

Fig. 10

See overleaf for oil pipe connection details

(OPTIONAL)


OIL SYSTEM FOR ADJUSTABLE DIFFERENTIAL

When the EGTA-212 differential is used an oil pump must be fitted to the gearbox. (See details of EGT-265-AS OPTIONAL OIL PUMP KIT later in this manual). In addition to the standard optional oil pump kit, a secondary inlet (located in the diff cap) is used to feed oil directly into the differential. To facilitate this, EGT-301-A maincase assembly replaces the standard EGT-301. Customers with who wish to install an adjustable diff into a gearbox with a standard diff cap can modify the cap as shown below [drawing SK-2513]. To supply oil to the diff, the ‘oil in’ pipe should feature a T-piece to direct flow to the –3 inlet as shown in the diagram below.

OIL OUT –6 (to cooler)

standard OIL IN –6 (from cooler)

Take feed from here and port to diff inlet (-3 JIC)

EGT-301-A (uses SK-2513 diff cap)

Note:- The port position shown in SK-2513 is as supplied by Hewland Engineering with EGT-301-A however it can be machined in other orientations on the diff cap or maincase (as long as it is on a 1.378” / 35mm PCR) if needed. Some existing bespoke bellhousings may require modification to clear this inlet (or to accommodate the additional feed pipe).

Fig. 10a


3 PLANET DIFFERENTIAL - EGTG-212

Fig. 11

(OPTIONAL)


4 PLANET DIFFERENTIAL - EGT-212-4PS

Fig. 12

(OPTIONAL)


Fig. 13

30

DIFF. CAP AREA (ASSEMBLY)

NOTE: PLEASE REFER TO CONTENTS PAGE FOR OPTIONAL TRIPOD GAITOR


SELECTOR BARREL ASSEMBLY

Fig. 14


RATIO CLUSTER ASSEMBLY

Fig. 15


SLAVE CYLINDER ASSEMBLY (TE-258-ASSY)

Fig. 16


Item No. Stock Code Description Qty.Per. 1 0460-12-18 WASHER 2 2 102-205-11 SPRING 1 3 102-260-4 DETENT PLUNGER 1 4 102-260-9 SPRING 1 5 104-226-1 HUB 2 6 104-226-2 NEEDLE ROLLER BEARING 6 7 104-233-1 PINION SHAFT GEARS 6 8 104-234-4 LAYSHAFT SPACER 1 9 104-235-1 INPUT SHAFT GEARS 4 10 105-229-1 ROLLER BEARING 1 11 105-229-4 ROLLER BEARING 1 12 105-234-8 DISC SPRING 1 13 305-03-M121P ADAPTOR 2 14 BEA-001 ROLLER BEARING 1 15 BEA-037 BALL BEARING 1 16 BEA-038 BUSH 2 17 BEA-059 PLAIN BEARING 1 18 BEA-099 ROLLER BEARING 1 19 BEA-175 BALL BEARING 1 20 BEA-176 BALL BEARING 2 21 BEA-177 BALL BEARING 2 22 CIR-052 WIRE RING 1 23 CIR-063 WIRE RING 1 24 CIR-082 CIRCLIP 1 25 CIR-083 CIRCLIP 1 26 CIR-084 WIRE RING 1 27 DG-232-A4D CLUTCH RING 3 28 DOW-024 DOWEL 1 30 EGT-301

EGT-301-A MAINCASE (STANDARD) MAINCASE (FOR ADJ DIFF)

1

31 EGT-201-1 SELECTOR COVER 1 32 EGT-302 BEARING CARRIER 1 34 EGT-208 DIFF END COVER 1 35 EGT-212 DIFFERENTIAL ASSEMBLY 1

Item No. Stock Code Description Qty.Per. 39 EGT-218-A GEARBOX SIDE TRIPOD JOINT 1 40 EGT-221-AP MAINSHAFT 15/(54) 1 41 EGT-221-AW FINAL DRIVE WHEEL 1 42 EGT-237-1 REVERSE IDLER 1 43 EGT-239- CLUTCH SHAFT 1 44 EGT-246-1 REVERSE SELECTOR RAIL 1 45 EGT-249 REVERSE SELECTOR FORK 1 46 TE-250 SELECTOR FORK 3 47 EGT-260 SELECTOR BARREL 1 48 EGT-260-1 BARREL DRIVER 1 49 EGT-260-2 NEUTRAL BLOCKER 1 50 EGT-260-3 SELECTOR RACK 1 51 EGT-260-6 PAWL 1 52 FT-248-4-020 SHIM 1 53 FTR-201-1 SELECTOR RACK STOP 1 54 FTR-210-35 PLUNGER 1 55 FTR-210-36 PLUG 1 56 FTR-237-1 REVERSE IDLER SPIGOT 1 57 FTR-237-2 SLEEVE 1 58 FTR-260-4 SELECTOR RACK WASHER 2 59 FTR-260-5 SLEEVE 1 60 HC-237-2 NEEDLE ROLLER BEARING 1 62 HP-M-9003 PLUG 1 63 HP-M-9004 MAGNETIC DRAIN PLUG 1 64 HP-M-9005 STUD 6 65 HP-M-9015 DOWEL 4 66 HC-202-8 PLUG 2 67 HP-M-9042 DOWTY WASHER 4 69 HP-N-9006 SOCKET HEAD SCREW 2


Item No. Stock Code Description Qty.Per. 70 IGT-250-1 SELECTOR FORK PIN 3 71 LD-202-9 WASHER 6 72 LIP-015 OIL SEAL 1 73 LIP-075 OIL SEAL 1 74 LIP-030 OIL SEAL 1 75 LIP-048 LIP SEAL 1 76 LIP-046 LIP SEAL 1 77 NUT-004 KAYNUT 11 78 NUT-005 K-NUT 6 79 NUT-008 K-NUT 4 80 ORI-001 O-RING 1 81 ORI-204 O-RING 1 82 TE-258-ASSY SLAVE CYLINDER ASSY 1 86 ORI-097 O'RING 1 87 ORI-102 O-RING 1 88 PLU-039 M14 BLANK PLUG 2 89 SCR-022 SOCKET CAP HEAD 2 90 SCR-046 BUTTON HEAD SCREW 3 91 SCR-117 SOCKET CAP SCREW 1 92 SCR-121 SOCKET SET SCREW 2 93 SGT-244-13 SKT CAP SCREW 4 94 SPH1078-M3 PLUNGER 1 95 EGT-201-5 BREATHER/ANTI-ROTATION 1 97 SPR-057 COMPRESSION SPRING 1 98 SPR-058 COMPRESSION SPRING 1 99 STU-036 STUD 10 100 STU-037 STUD 3 101 STU-038 STUD 4 102 TE-201-4 COVER PLATE 1 103 TE-202-1 DETENT PLUNGER PLUG 1

Item No. Stock Code Description Qty.Per. 104 TE-202-7 BEARING RETAINING PLATE 1 105 TE-226 REVERSE HUB 1 106 TE-228 REAR HUB 1 107 TE-229 THRUST WASHER 1 108 TE-229-1 SHIM 1 109 TE-231 REVERSE SLIDING GEAR 1 110 TE-234 LAYSHAFT VARIANTS 1 111 TE-234-2 BEARING INNER TRACK 1 115 TE-260-5 SELECTOR BARREL BOLT 1 116 TE-260-7 SELECTOR BARREL SPACER 1 122 VG-201-9 D-RING STRIP 1 123 WSH-017 DOWTY WASHER 2 124 WSH-027 WASHER 4 125 WSH-028 M8 WASHER 11 127 F3D-236-1 WASHER 1 128 HP-M-9037 BANJO JOINT 1 129 HP-M-9038 SEALING WASHER 2 132 EGT-218-4 STOP PIECE 1 133 SCR-003 GRUB SCREW 2 134 TE-258-DL WIRE RING 1 135 EGT-206-1 SELECTOR RACK SUPPORT 1 136 EGT-234-1 STOP 1 137 HP-M-9029 SKT BUTTON HEAD SCREW 1 138 PCT-201-1 COVER PLATE 1 139 INA-002 KEENSERT 3 140 EGT-237-2 REVERSE IDLER SPIGOT 1 141 SPR-047 COMPRESSION SPRING 1 142 PLU-059 BLANKING PLUG 1 143 SCR-048 SOCKET CAP SCREW 1 144 ORI-080 O-RING 1 145 SPH1084-M3 ANTI-ROTATION PIN 1 146 EGT-234-1A STOP COLLAR 1


Wide ratio kit (gearboxes built with these parts are referred to as WGT-200)

Item No. Stock Code Description Qty.Per. 1 WGT-239- CLUTCHSHAFT 1 2 WGT-RATIO-HUB RATIO SET - HUB 1 3 WGT-RATIO-RATIO INTEGRAL 1ST/2ND GEARSET 1 4 WGT-RATIO-STD RATIO SET 1

1

3 2 4

Fig. 17


Inverted dog ring spline - Optional parts

The inverted spline clutch rings offer greater strength and improved sliding which many drivers report gives smoother shift. These parts can be fitted to any EGT/WGT gearbox, simply replace the standard clutch rings & hubs with parts shown:-

Fig. 18


OPTIONAL OIL PUMP KIT

Fig. 19

CORRECT ORIENTATION TO ASSEMBLE OIL PUMP


OPTIONAL TRIPOD GAITOR

Fig. 20

Associated circlip - CIR-114 Associated o-ring - ORI-124


GEARBOX TOOLING

Fig. 21


Technical Bulletins


Manual Modifications 23/09/11 Page 25 - Optional Tripod Gaitor information added. Pages 2/3 page and figure numbers updated. 09/01/12 Page 4 - WGT information added. Page 17 updated note. Page 18 added (new page for adj. diff. oiling info) Pages 19 & 20 added (optional 3 & 4 planet diffs) Page 25 added (new page for WGT internals). Page 26 added (new page for inverted dogs) 04/10/12 Page 21 - Note added re. optional tripod gaitor 19/10/12 Page 30 - Picture changed to show optional tripod spider 21/11/13 Page 25 - Corrected selector fork part number

servicing instructions and illustrated parts list for hewland egt… · 2014. 1. 6. · the egt...

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