Perkins L4 Workshop Manual - L-36 Fleet
Perkins L4 Workshop Manual - L-36 Fleet
Perkins L4 Workshop Manual - L-36 Fleet
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
~<br />
L<br />
~ I<br />
~<br />
..,<br />
LJ<br />
u<br />
SCHEDULE OF CLEARANCES & TOLERANCES (V:<br />
u<br />
All threads ~ed 00 the <strong>L4</strong> Eogine except 00 prGprietary equipment<br />
and the crankshaft are Unified Series, aod Americao Pipe Series. Tbe<br />
crankshaft aod starting dog nut are threaded 1 inch Americao Natiooal<br />
Fine of 14 T.P.I.<br />
U I<br />
U<br />
u<br />
u<br />
u<br />
u<br />
u<br />
The new threads are not interchangeable with B.S.F. and althougb<br />
B.S. W. have the same number of threads per inch as the Unified Coarse<br />
Series, intercbanging is not recommended, doe to a difference in thread form.<br />
2.<br />
3.<br />
4.<br />
u<br />
u<br />
5.<br />
u<br />
6.<br />
u<br />
u<br />
J<br />
~ J<br />
The data regarding clearnnces and tolerances are given as a guide<br />
for personnel engaged upon major overhauls.<br />
Tbe figures in the column .. Permissible Dimensions ,t are the<br />
drawing sizes to which tbe parts are made. These dimensions are<br />
given in limit farm and represent tbe minimum and maximum sizes<br />
to which parts may be accepted when new, as, ror example,<br />
.4985<br />
-:499 The difference 111,ntPn '1 .-. fnr between - " qh"ft ~ the ni"m~tpr minimum and maximum dimensions<br />
quoted in para. 2 is known as thc manufacturing tolerance. This<br />
tolerancc is necessary as an aid to manufacture and its numerical<br />
valuc is an expression of the accuracy of the design; it mayalso be<br />
considered as a numerical expression of the desired quality of workmanship.<br />
For the example referred to in para 2 thc tolerance is<br />
0.0005.<br />
If when carrying out a major overhaul it is found that a bush and<br />
corresponding shaft have worn and that the majority of wear has<br />
taken place in the bush it may be necessary to renew the bush only.<br />
Similarly if the majority of wear has taken place on the shaft it<br />
might only be necessary to rencw thc shaft.<br />
During the overhaul of wom components personal initiative must<br />
be exercised at all times. It is obviously uneconomical to return<br />
wom parts to service with an expectation of lire which may involve<br />
labour costs agaiÎ1 at an carly date.<br />
Further information can be obtained on request [rom the Service<br />
Division, <strong>Perkins</strong> Engines Ltd., Peterborough, England.<br />
To ensure rou obtain the best results from your engine<br />
and to safeguard your own guarantee, fit only genuine<br />
<strong>Perkins</strong> Parts. These are readily obtainable throughout<br />
the wor Id.<br />
I<br />
Page VI