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
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174 
Allison WT debut
Page 16
If you've noticed an error in this article please click here to report it so we can fix it.
• Allison Transmission has unveiled the prototype of its World Transmission (WT) automatic gearbox, which will be offered as an original equipment option by 1991.
The WT transmissions comprise a series of automatic gearboxes, which will handle between 195 and 330 gross kW (160-440hp). Allison claims they will be suitable for medium and heavy-duty trucks and buses around the world.
The transmission is particularly suitable for rear-engined buses. as it is controlled electronically, thus doing away with complicated linkages. The manufacturer claims that the WT transmissions are smaller and lighter than competitive units, as well as offering between 5-10% better fuel economy. The company concedes that automatic transmissions have a 5-7% efficiency loss in a straight motorway run. In urban driving, however, it says the automatic selection of the right gear, together with reduced maintenance costs, means the total cost of running an automatic can be lower.
The electronics in the new gearboxes work with Allison's ATEC 11 adaptive electronic control system. The system has a diagnostic memory for easier servicing, and can be programmed to provide four, five, or six speeds, depending on the operation.
We had the chance to drive a Van Hool 7005 coach fitted with the new WT gearbox, and can confirm that the prototype, at least, provides smooch, easy gearchanging, with a simple button box for gear selection at the side of the driver. Allison has included a torsional damper in the WT gearbox to absorb the shock loads from the engine, and so make gearchanging smoother.