1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152 
it Your complaints 4 Heater performance
Page 140
Page 141
If you've noticed an error in this article please click here to report it so we can fix it.
The lack of adequate heater output in the winter, which appeared to be mainly confined to turbo-charged units, especially in Scandinavia, was not really a United Kingdom problem. As Chrysler is selling an ever-increasing percentage of truck production to the Continent of Europe and beyond, it was decided that the performance of the heater unit on both the domestic and the cold climate specifications should be improved.
Investigations showed that one of the major problems was coolant water by-passing the thermostat seat faces owing to insufficient clamping of the cover assembly. Changing the aluminium die-casting cover from an overall oval shape to one of a figure of eight enabled total peripheral pressure to be applied to both thermostats.
Another problem found was that on the type of thermostats specified there was i:oo great a water bleed through the thermostat unit and so the Western Thomson wax capsule units were specified. These units had the same rating on the UK specification as previously used, but the cold climate specification was uprated.
On the Mercedes engine it was found necessary to incorporate a restrictor in the coolant by-pass system. A two-speed control for the heater blower unit which will enable an operator to use the blower at a reduced speed in the winter months, is about to be specified.
5 Door equipment
During the original specification discussions for this range of trucks Chrysler was conscious not only of the necessity for low weight and price, but also meeting very high quality and reliability standards. In the particular area of door equipment, one or two cardesigned components were used which were already tooled. In hindsight it was realised that they were inadequate for the much harsher use given to them by some truck operators.
a) Door check strap spring On a number of high mileage reports details were received of failure of the door check strap spring. On examination they appeared to have failed prematurely owing to fatiguing from sudden wind gusts catching a door on opening and also from tilt cab operators lifting the cab while the doors were open, so putting much greater strain on the spring. Added to the operator problem was the fact that that spring was incorporated in the hinge. Consequently the operator had to purchase the complete hinge assembly.
Redesigning of the spring and increasing the crosssectional area was carried out and the spring was made a separately serviceable item. It was also found that with spring failure, excessive load was being placed on the lower hinge-mounting plate in the inner door skin and this plate was stiffened by welding around its periphery. These improvements will be incorporated shortly.
b) Window regulator handle knobs The loss of a window winder knob obviously had annoyed users and so a unifi Chrysler-designed handle now used on virtually European products. This co plies with all known leg lation.
c) Exterior handle push
Operators had origina complained of difficult do( lock release as they were u able to depress the hail( release button far enouc. This was found to be a va criticism, so button travel lA immediately increased allo, ing an earlier disengagemE of the locking mechanism. the same time the die-casti form on the inside of t handle portion was revised remove a sharp radius. Ott mods included a longer r between the button and lo plus provision for exten adjustment.
d) Doo'r lock interior handle The original handle spe ifled was an existing tooll handle, but being of mair plastic construction it ga the operator the opinion th it would not be reliable. overcome this customer co cern it was decided to chani from plastic to a die-castinc e) Door lock internal linkage Another irritating conditic reported by some operatc was the difficulty in door-loi operation from inside the ca It was established that tl remote control link from II handle to the lock was beir malformed with continuo] operation and the linkai clips were jumping out their retainer points. By coi siderably increasing the guac of this link and incorporatir an improved clip retentic arrangement the problem 11 been overcome.
6 Throttle linkage
With high mileage operatic on the Mercedes engine was found that there was tendency to lose full-thrott operation and an increase pedal effort was required.
The Mercedes linka which went round three sid the engine block, was disntinued, and a more direct ate from the pedal relay to ; pump was incorporated. is modification has reduced dal effort and lost motion the linkage.
On the non-Mercedes units, 311 the tolerances went one iy in the cab and frame ;emblies, there could be a s of throttle movement at
top end of the range. e ratio of the relay levers 5 been changed and acetal ,erts are now incorporated
the pedal cross-shaft ickets in place of nylon erts. A metal throttle pedal ige arrangement instead of iber is used, resulting in a luced load system and ire than adequate throttle eration.
me 100,000-mile reports Heated that oil tightness s showing as a problem in her mileages. Obviously 3 could have more serious 'sequences if not detected I rectified by operators, so extensive survey was con-3ted of higher mileage units.
following action was en: a) All external cover fixing bolts are now barrelled with Loctite sealant before fitting.
b) The strength and stiffness of cover flanges was in creased as necessary.
c) Sealant is painted directly on to all cover flanges so eliminating the possibility of operator error using hand-application methods. During the survey it was also discovered that under certain operating conditions, such as continuous highspeed motorway use, the sixspeed box input shaft and lay-shaft bearings were showing signs of distress. This could have led to failure at high mileages.
In the interests of maintaining a good reliability record it was decided that, if possible, an increased capacity bearing should be specified. Fortunately, bearings were found which were interchangeable with the existing ones, so reducing the expense of total re-specification of surrounding structures and allowing the latest bearings to be fitted during any service overhaul.
8 Tilt cab oil check access
One annoying problem reported by operators of tilt cab units was the fact that it was necessary to lift the cab to check the engine oil level or get at the oil filler point. The access panel already specified in the fixed cab was subsequently incorporated into the tilt cab at an obvious increase in cost, but to the benefit of the user.