• Hi Guest! Being a Paying Supporter is NOT a requirement to participate at BCF. However, subscribing will help ensure we can continue to serve the LBC community for years to come. If you enjoy BCF and find our forum a useful resource...Please consider supporting us by **Upgrading**
    (PS: Subscribers don't see this banner)
Tips
Tips

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

Tropical TR

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

Regards,

Walter
 
Similar threads
Thread starter Title Forum Replies Date
H TR4/4A A-type overdrive pump Triumph 4
Got_All_4 TR6 Refurbishing gearbox with A type overdrive Triumph 7
D TR2/3/3A Type A overdrive not engaging Triumph 0
D TR2/3/3A Type A overdrive not engaging Triumph 16
M TR4/4A A type Overdrive Oil Leak Fix Triumph 3
Graham H TR2/3/3A A type overdrive Triumph 6
KVH General TR Type A Laycock Overdrive Questions Triumph 8
C TR2/3/3A A-type overdrive drain plug oring Triumph 1
J TR4/4A TR4 A Type Overdrive Part mixup Triumph 4
CJD TR2/3/3A A type Overdrive Seal Triumph 9
T Spitfire J Type overdrive Triumph 2
T TR2/3/3A Question on A-type overdrive solenoid Triumph 21
BillyB62 TR2/3/3A Type A TR3 Overdrive Wiring Triumph 13
T TR2/3/3A Question on A type overdrive spec for "clutch movement from direct to overdrive" Triumph 7
M_Pied_Lourd TR6 J Type Overdrive High Pressure Filter Cap-Major Problem Triumph 6
R A Type Overdrive reassembly question Austin Healey 3
R TR2/3/3A A-Type overdrive question Triumph 8
T TR2/3/3A My A-Type overdrive rebuild project, some questions Triumph 36
T TR2/3/3A Will Spitfire D-type overdrive work in TR3 with TR4 transmission? Triumph 3
R Overdrive [Type A] brake ring gaskets Austin Healey 1
R TR2/3/3A Overdrive [Type A] Brake Ring Gaskets Triumph 14
J General TR D Type overdrive not working need suggestions Triumph 5
Gordon_Dedrick TR2/3/3A A type overdrive installation Triumph 7
T TR2/3/3A Type-A Overdrive Handling Differences Triumph 9
A TR5/TR250 A-type overdrive questions Triumph 25
71tr TR6 Overdrive Mount / J-type on A-type frame Triumph 1
D TR6 76 TR6 J Type Overdrive Triumph 7
Gordon_Dedrick Testing an A type overdrive Triumph 20
Simmo I need help with J Type Overdrive Triumph 15
Q "A" Type Overdrive Annulus End Float!! Triumph 4
D A type overdrive question. Triumph 3
John_Mc J-Type overdrive for sale on CL Triumph 4
KVH More on A Type The Overdrive Triumph 2
Coyote1 J Type Overdrive engage problem Triumph 3
J A Type Overdrive Triumph 17
K TR6 TR6 J Type Overdrive...Link to Schematic? Triumph 3
O J Type Overdrive Conversion Triumph 19
Marvin Gruber J type overdrive unit on BCF classifieds Triumph 2
HerronScott TR4/4A TR4A A-type overdrive and Moss Europe TR2-4A cat. Triumph 2
T A-type Overdrive & Gearbox Triumph 9
TR3TR6 J-type overdrive question Triumph 5
CinneaghTR A-type Overdrive Model Number Triumph 14
71tr J-type Overdrive Pressure Port Question Triumph 2
T A-type overdrive / gearbox trouble shooting Triumph 69
R_Lyle TR6 J-Type or A-Type Overdrive for 1972 TR6 Triumph 18
TR4A_IRS Looking for a J Type Overdrive? Triumph 0
7 question after testing a J type overdrive Triumph 5
mgedit Fluid for J-Type Overdrive Triumph 22
Got_All_4 A type overdrive that has been sitting for years Triumph 6
Tinkerman Type A overdrive Triumph 7

Similar threads

Top