>miker15@juno.com wrote:
>>
>> 1)forget the o/d on 3rd - its basically about the same ratio as 4th
>
>More like midway on mine. Clausager says 3rd - 5.402, 3rd o/d - 4.429, 4th
- 3.909, 4th
>o/d 3.205. OK, not midway, but nearer midway than 4th.
>
>PaulH.
I think it must depend on the trans. My '67 with a 3 synchro trans and
overdrive has pretty much the same 4th and 3od ratios. Maybe 100rpm
difference, but not much more. The Complete Official MGB 1962-1974 (I think
the most complete and thorough shop manual that I've seen) shows:
Overdrive .802
Top 1.0000:1
Third 1.3736:1
Second 2.2143:1
First 3.6363:1
Reverse 4.7552:1
Translating that overdrive onto third would give a ratio of 1.10104
The overall Ratios are listed:
Ratio M.P.H / 1000 R.P.M.
Overdrive 3.135:1 22.3
Top 3.909:1 17.9
Third 5.36 :1 13.09
Second 8.65 :1 8.11
First 14.20:1 4.94
Reverse 18.60:1 3.77
Again translating 3OD would give a ratio of 4.288:1 and 16.3625 MPH/1000RPM
- maybe my gearbox is close ratio, because it lists at
Overdrive 3.135:1 22.3
Top 3.909:1 17.9
Third 4.956:1 14.1
Second 6.332:1 11.0
First 9.577:1 7.3
Reverse 18.588:1 3.7
Which would give 3OD of 3.9648:1, and 17.65 MPH/1000RPM - nearly the same
3OD as 4th without OD. I never thought about it before, no I'm going to
have to go check.
Phil Bates
58 MGA
66 Citroen DS21 Manual Pallas
67 MGB
75 Jaguar XJ12C
66 Land Rover
52 MG TD replicar (VW)
86 Peugeot 505 Turbo Gle
86 Honda Accord LX-i
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