Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Roadster 3.7 gearing

Hello,

can anyone confirm or correct my following findings?
Since I have this speedo deviation with my 3.7 Roadster, which hopefully can be corrected by programming, I had a closer look at the type of gearbox and rear axle that is used for this car.

Ford produces three types of MT-82 gearboxes, which were designed together with Getrag:

6MTI500-L1, used for LR Defenders, Ford Transit and Roadster 3.7
6MTI500-L2, used for Ford Mustang V6
6MTI500-L3, used for Ford Mustang V8

These three types have different gearings, the gearing for L1 is:
1-------2-------3-------4-------5-------6-------R
5,441---2,839---1,721---1,223---1-------0,794---4,935

The rear axle ratio seems to be 3,45. (although my handbook says 3,07, mistake?)

My tires are 205/65R15 with a circumference of 1968mm

That results in the following speeds (km/h) with 1000rpm:
1-------2-------3-------4-------5-------6-------R
6,3-----12,1----19,9----28,0----34,2----43,1----Who cares

I normally don't use the first gear because it is too short, only occasionally on very steep hills.
At least that corresponds to these numbers.
Again, please feel free to correct or comment.

Markus

edit: Is there a bether way to show tables?

Markus

Have not checked the ratios but have the same issue with my speedo, it is at least 10-15% out measured against several GPS Speedo apps. I have raised this as a warranty rectification issue with Williams Morgan and they said the speedo is adjustable but not sure how. They will be addressing it when it goes in for its next service.

Adrian - does your speedo read higher or lower than GPS? I haven't checked mine yet with a GPS but it shows 60mph at 1800rpm.
Don.

Don,

with my tires and in 6th gear it should show 2240 RPM at real 60mph. At least if my calculations are not wrong.
Markus