Thwaites SPRITE NIMBUS, Руководство пользователя

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SERVICING 40M-3 GEARBOX - SPRITE/NIMBUS MODELS
REMOVAL OF GEARSET: (CONTD.)
5. Undo the nut (item 63) on the reverse pinion shaft and remove the reverse pinion
assembly.
6. The main dis-assembly of the gearbox is now complete.
7. Removal of the circlip from the front part of the lay shaft will enable the forward
part of the layshaft assembly to be slid off.
** REMOVAL OF PRIMARY SHAFT BEARING:
1. Only remove this bearing when replacement is required as it is frequently spoiled in
removal. Remove the circlip (item 24) and spacer (item 25). Press the ballrace back
until the oil hole in the primary shaft is covered by it. Now fill the primary shaft
bearing with very heavy oil or grease. Support the primary shaft rigidly and
vertically. Use a drift which is the same bore diameter as the worn bush. Enter it into
the bearing and strike it a number of heavy blows. The bearing will be forced out by
the hydraulic action of the grease.
RE-ASSEMBLY OF SMALL COMPONENTS:
1. If the gearbox has been used on continuous heavy duty it is advisable to replace
ballraces and oil seals as a matter of course. New oil seals should be fitted by
pressing them in with a flat steel plate which covers their entire area, otherwise they
may buckle and be spoiled. Output couplings frequently show heavy wear where the
oil seal has contacted them. When this condition is observed, the coupling should
be replaced.
2.** A new primary shaft bush must be pressed in with a suitable drift and then reamed
in position with a 5/8" diameter reamer. The pilot diameter of the mainshaft should
be a free running fit without undue shake.
3. The shafts and gears in the gearbox are treated with a phosphating process in order
to ensure satisfactory performance. Do not attempt to remove any apparent
discolour-ation by polishing bearing surfaces on shafts or in the bores of gears as
seizure may result from the exposure of naked steel surfaces.
4. If the reverse idler gear is rebushed, this bush (item 67) is the correct size when
pressed in, and will not need any further treatment. If this gear has been re-bushed,
then re-placement of the reverse idler shaft (item 62) is also advised.
** This applies up to serial no. 40427 whence a needle roller bearing was fitted.
RE-ASSEMBLY OF MAIN GEARBOX:
1. The case should be clean inside and out.
2. Fit the layshaft bush (item 76) with the slot on the outside of the bush at the top.
3. Fit the reverse idler gear assembly complete, the woodruff key (item 61) is most
important. The gear (item 66) should be a free running fit when the reverse shaft has
been fully tightened up.
4. The layshaft (item 73) should now be partly sub-assembled. Fit the inner first speed
gear (item 72b), layshaft gear (item 78) and secure with circlip (item 24). Check that
the gear (item 72b) has at least .007" end float. Slip on the sliding gear (item 74, and
insert this sub-assembly, through the top of the gearbox into its correct position,
locating it in bush (item 76). Through the ballrace bore in the back of the case, insert
the reverse gear which is part no. T4558 (item 72a) and the spacer T4548 (item 71).
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