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TR2/3/3A Type A Overdrive, Physical Differences between Roadster Brands?

Tropical TR

Jedi Hopeful
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Excepting the ratio difference for some applications (28% for Jags vs. 22% for others?), was there any physical difference in the Type A sports overdrives between those used in TRs, Austin-Healey, MG, etc.? Or are the differences only in the rear casing dimensions? I know the sedans are a different story with solenoid and speedometer gear location.

In other words, is it all the same using an A-H, MG, etc. Type A OD with an original TR3/4 rear casing. Will it mount properly in a TR3 with no changes and with sloped speedo drive, solenoid, etc. in the same places?

Regards,

Walter
 

TR4nut

Yoda
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There are some differences but it may be possible to swap cases I think. Healey A types for example do not have the long studs attached that mount the overdrive to the gearbox adaptor plate like TRs do. Physically though, the case dimensons I believe are identical.

Other things are different also, the solenoid brackets are different though I've looked at the Healey ones and think they could be used. The accumulator piston setup could be different as well, though it may not affect operation really.
 
OP
T

Tropical TR

Jedi Hopeful
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Thanks Randy. I hadn't thought about the studs at all. Much appreciated!

Regards,

Walter
 
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