Hewland NMT Servicing Instructions Download Page 2 | Manualshive

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Hewland NMT Servicing Instructions Download Page 2

PAGE 2

© Copyright Hewland Engineering Limited

CONTENTS :-

page

page

Technical

specification

4 Changing

gear

ratios 13

General

notes

5 Powerflow

differential

14

Differential

bearing

preload 6 Differential

Options 15

Pinion

shaft

mounting

7 Illustrated

Parts

List 22

Pinion

shaft

bearing

preload 8 Gearbox

Tooling 35

Crownwheel backlash setting

9

General Technical Bulletins

36

Sequential

barrel

setting 10

Oil

system

layout

38

Gearbox

assembly

11

Recommended

Tightening

39

Torques

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1
2
3
4
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Summary of Contents for NMT

Page 1: ...ewland Engineering Limited SERVICING INSTRUCTIONS AND ILLUSTRATED PARTS LIST FOR HEWLAND NMT GEARBOXES HEWLAND ENGINEERING LTD WALTHAM ROAD WHITE WALTHAM Last Update 10th July 2012 MAIDENHEAD BERKSHIR...

Page 2: ...w differential 14 Differential bearing preload 6 Differential Options 15 Pinion shaft mounting 7 Illustrated Parts List 22 Pinion shaft bearing preload 8 Gearbox Tooling 35 Crownwheel backlash setting...

Page 3: ...ayshaft Assembly 27 fig 3 Pinion shaft bearing preload 8 fig 14 Pinion Shaft Assembly 29 fig 4 Crownwheel setting 9 fig 15 Selector Assembly 31 fig 5 Sequential barrel setting 10 fig 16 NLT 218 Tripod...

Page 4: ...and differential assembly can easily be changed without removing the gearbox from the vehicle Heat treated nickel chrome steel is used to manufacture all gears and shafts The selector forks are also s...

Page 5: ...ing Replacement Bearings can only be removed or renewed if the casings have been warmed in an oven or with a blowlamp In the latter case keep the blowlamp moving while heating the casing Note Do not o...

Page 6: ...ry to achieve 4 6 lbs ft of bearing preload torque to turn the diff assembly in it s bearings when oiled The table below is to inform you of which sideplate spacers should be used with which crownwhee...

Page 7: ...side diameter of tool SK 1913 Fit tool SK 1470 A into the maincase diff bearing bore and use feeler gauges to measure the gap between the tool and the pinion front face This clearance should comply wi...

Page 8: ...be adjusted by grinding to give a bearing preload torque of 20 25 lbs ins with oiled bearings measure torque as when setting pinion shaft using tool SK 1913 FIGURE 3 It is essential that the pinion be...

Page 9: ...ash figure should be taken from the card supplied with the gears If the measured backlash is incorrect rectify it by removing some shims 103 from behind one diff bearing and inserting them behind the...

Page 10: ...s 19 and spacer 14 in place in the bearing carrier and slide the whole thing onto the dummy shaft of fixture SK 1451 e Tighten the pinion shaft nut 111 onto the end of the dummy shaft ensuring that th...

Page 11: ...e height of 1 450 It is also adviseable never to re use the circlip 78 e Assemble the drum 8 bearing 28 pin 10 retaining plate 11 barrel driver 13 and shifter spindle 7 Assemble the drum shifter 6 gui...

Page 12: ...o slide out of the gear cluster Whilst locating the gear cluster lightly operate the selector rack 75 to ensure correct location of the barrel and driver Tighten the pinion shaft nut using tool No SK...

Page 13: ...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 fig...

Page 14: ...e required to turn the other using tool SK ____ When the diff is assembled the preload torque must be at least 10 lbs ft but can be much greater if required New plates run in so a higher preload is ad...

Page 15: ...PAGE 15 Copyright Hewland Engineering Limited FIGURE 7 DGC 212 Diff Assembly superseded March 2010...

Page 16: ...PAGE 16 Copyright Hewland Engineering Limited DGC 212 Diff Assembly March 2010 onwards FIGURE 7a...

Page 17: ...PAGE 17 Copyright Hewland Engineering Limited FIGURE 8 DGC 212 S Diff Assembly superseded March 2010...

Page 18: ...PAGE 18 Copyright Hewland Engineering Limited DGC 212 S Diff Assembly March 2010 onwards FIGURE 8a...

Page 19: ...PAGE 19 Copyright Hewland Engineering Limited TPT 212 Diff Assembly FIGURE 9...

Page 20: ...imited IN ORDER TO FIT THE NLT DIFFERNETIAL IN THE NMT BOX THE NLT SIDE PLATE NLT 205 WILL NEED TO BE FITTED FIGURE 10 NLT 212 Diff Assembly superseded March 2009 This differential was superseded by t...

Page 21: ...need to be modified to fit this differ ential Please contact Hewland Engi neering for details This differential superseded the differential shown on the previous page The differences are a new case e...

Page 22: ...PAGE 22 Copyright Hewland Engineering Limited ILLUSTRATED PARTS LIST...

Page 23: ...PAGE 23 Copyright Hewland Engineering Limited FIGURE 11...

Page 24: ...BOLT CROWNWHEEL BOLT 10 56 NMT 221 AW CROWNWHEEL 1 65 OUTPUT FLANGE OUTPUT FLANGE 2 81 FGC 205 4 OIL SEAL 2 82 FGC 205 3 BALL BEARING 2 83 FGC 205 1 TAPER ROLLER BEARING 2 85 DIFFERENTIAL DIFFERENTIAL...

Page 25: ...PAGE 25 Copyright Hewland Engineering Limited FIGURE 12...

Page 26: ...OLLER BEARING 1 107 HC 237 4 THRUST WASHER 2 113 OIL FILTER OIL FILTER 1 114 HP M 9004 MAGNETIC PLUG 1 115 HP M 9042 SEALING WASHER 3 116 ORI 001 O RING 2 117 OIL SPRAY OIL SPRAY 1 121 VG 201 9 SEALIN...

Page 27: ...PAGE 27 Copyright Hewland Engineering Limited FIGURE 13...

Page 28: ...104 234 4 LAYSHAFT SPACER 2 47 TE 234 1 SPACER 1 50 TE 234 LAYSHAFT 1 51 BEA 001 ROLLER BEARING 1 96 NMT 239 13 CLUTCH SHAFT 1 97 DGB 244 12 BALL BEARING 1 98 FT 244 11 OIL SEAL 1 99 DGB 244 CLUTCH SH...

Page 29: ...PAGE 29 Copyright Hewland Engineering Limited FIGURE 14...

Page 30: ...TIO STD GEAR RATIO 6 19 DG 232 A4D CLUTCH RING 3 20 104 226 1 HUB 3 30 TE 231 REVERSE PINION GEAR 1 32 BEA 062 TAPER ROLLER BEARING 1 33 NMT 228 REVERSE HUB 1 34 NMT 230 1 LOCKING RING 1 35 FT 219 1A...

Page 31: ...PAGE 31 Copyright Hewland Engineering Limited FIGURE 15...

Page 32: ...REVERSE SELECTOR FORK 1 60 TGTA 206 2 SELECTOR RACK STOP 1 61 WSH 013 BONDED SEAL 1 62 HP M 7018 PLUNGER 2 63 HP M 7018 A SPRING 2 SELECTOR ASSEMBLY ITEM No PART No DESCRIPTION QTY 64 HP M 7017 PAWL 2...

Page 33: ...PAGE 33 Copyright Hewland Engineering Limited NLT 218 TRIPOD ASSEMBLY FIGURE 16...

Page 34: ...PAGE 34 Copyright Hewland Engineering Limited Variable Parts...

Page 35: ...PAGE 35 Copyright Hewland Engineering Limited Gearbox Tooling FIGURE 17...

Page 36: ...ls it will be on the front face toe end of gear It is recommended that that the D specification bevels are always run with a mating gear of the same specification In extreme circumstances it may be po...

Page 37: ...PAGE 37 Copyright Hewland Engineering Limited NMT Technical Bulletin No 001 POSITION OF GEAR INDICATOR POTENTIOMETER...

Page 38: ...PAGE 38 Copyright Hewland Engineering Limited 23 March 2004 NMT OIL SYSTEM LAYOUT FIGURE 18 SEE HYD 041 FOR OIL SYSTEM PIPEWORK KIT REFERENCES OIL COOLERS ARE NOT INCLUDED...

Page 39: ...ARSE SERIES BOLTS CLASS 12 9 Nm lbs ins THREAD Nm lbs ins lbs ft M5 8 4 75 6 2 M6 12 7 112 9 3 M8 27 0 239 19 9 M10 x 1 50 40 0 354 29 5 M10 x 1 25 50 0 443 36 9 RECOMMENDED TIGHTENING TORQUES FOR MET...

Page 40: ...yright Hewland Engineering Limited Manual Modification History DATE MODIFICATION 21 10 2011 Page 40 added Page 25 26 Item 127 updated and item 143 added 10 07 2012 Page 33 Figure 16 updated to show la...

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