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Overdrive question..?
- Thread starter Ian R
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Healey 100
Jedi Warrior
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You will have to change the complete transmission with another one that includes the OD. I believe the main shaft on the non-OD tranny is quite different from the OD version, so it is not a matter of just adding an OD to back end of your non-OD transmission.
Years ago I did change another 100/6 with a non-OD transmission. It was not difficult and it worked OK. But it is harder today to find a rebuildable 100-6 transmission with an OD.
PS you probably have one of the non-OD Healeys that were built that way from the factory, there were some. I understand these came with a lower numerical rear axle which is a plus whether you make the conversion or not.
Years ago I did change another 100/6 with a non-OD transmission. It was not difficult and it worked OK. But it is harder today to find a rebuildable 100-6 transmission with an OD.
PS you probably have one of the non-OD Healeys that were built that way from the factory, there were some. I understand these came with a lower numerical rear axle which is a plus whether you make the conversion or not.
British_Recovery
Jedi Warrior
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Gearboxes can be swapped, but adding an overdrive to your existing 'box would require additional modifications. The main shaft, for example.
Bob
Bob
Bob_Spidell
Yoda
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If you can scare up the gearbox/mods Denis Welsh offers rebuilt ODs for sale outright:
https://www.bighealey.co.uk/healey-overdrive
If you can wait until the effects of Brexit fully register, the exchange rate might be more favorable.
https://www.bighealey.co.uk/healey-overdrive
If you can wait until the effects of Brexit fully register, the exchange rate might be more favorable.
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A BN4 that came with overdrive will have an "O" in the serial number. No "O", no overdrive.
It was originally built with an overdrive it has the "O" in the chassis number, is recorded on the heritage certificate and still has the wiring & switch gear.
I've been offered an unused "A" Type overdrive at a fraction of the listed price but he is unsure what vehicle it was actually intended for. I realise the main
shaft has to be replaced but as part of my restoration I will have the gearbox overhauled I thought this would be the time to do the change.
So, back to the question "are they all the same"...?
I've been offered an unused "A" Type overdrive at a fraction of the listed price but he is unsure what vehicle it was actually intended for. I realise the main
shaft has to be replaced but as part of my restoration I will have the gearbox overhauled I thought this would be the time to do the change.
So, back to the question "are they all the same"...?
Bob_Spidell
Yoda
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I'm getting ready to tear into my BJ8's OD, so I've been studying the parts catalog, and I've stayed at a Holiday Inn before--bad US TV commercial reference--so I'll go out on a limb and say, with a couple exceptions, they should be interchangeable. In particular, the gearbox->OD adapter plates vary (DWR has them). Earlier Healey ODs have a different brass drain plug with a (very handy) square stud for wrenches, whereas later one have a notched perimeter that requires a special wrench (or hammer and drift). The actuating piston sealing mechanism--rings vs. O-rings--varies between models, but they appear to be interchangeable. Healeys used a smaller, weaker accumulator piston so that OD engagement wasn't as traumatic, but some substitute the larger accumulator and spring--found, for example, on TR4s--for quicker OD engagement. I just had a conversation about gearboxes and ODs with Tom Monaco at Tom's Import Toys (https://tomsimport.com/), and he said the TR ODs they overhaul usually have more wear/damage to parts like thrust washers due to the more dramatic engagement. Driver technique can determine wear as well:
https://www.quantumechanics.com/
I would try to contact these people (above), as maybe with a photo or two they could identify the OD you are considering buying.
https://www.quantumechanics.com/
I would try to contact these people (above), as maybe with a photo or two they could identify the OD you are considering buying.
Randy Forbes
Yoda
Offline
To the best of my recollection, any Healey overdrive unit will fit on any__side or center-shift__Healey XMSN that has the ovd-specific mainshaft and adapter plate.
It has been my most recent experience that the 100/6, specifically mine (5/14-15/1958 build date) requires an overdrive with exposed solenoid linkage. When I attempted to fit an overdrive with an enclosed solenoid linkage, it did not clear the chassis.
I'm not sure when the change-over date was, but it would stand to reason that cars before that date *might* run into interference there.
This is an early style with exposed linkage (solenoid not yet mounted).
Another 100/6 unit.
I'm at a momentary loss for a good picture of the later type overdrive (somewhere, I have a picture of the fresh Quantum Mechanics ovd NOT fitting into my car...) but here's a bonus TR3 trans with a very similar overdrive; primary difference is the tail housing/mount, but many of the internals interchange, though they may be of different ratios, so some components would have to be swapped in sets.
It has been my most recent experience that the 100/6, specifically mine (5/14-15/1958 build date) requires an overdrive with exposed solenoid linkage. When I attempted to fit an overdrive with an enclosed solenoid linkage, it did not clear the chassis.
I'm not sure when the change-over date was, but it would stand to reason that cars before that date *might* run into interference there.
This is an early style with exposed linkage (solenoid not yet mounted).
Another 100/6 unit.
I'm at a momentary loss for a good picture of the later type overdrive (somewhere, I have a picture of the fresh Quantum Mechanics ovd NOT fitting into my car...) but here's a bonus TR3 trans with a very similar overdrive; primary difference is the tail housing/mount, but many of the internals interchange, though they may be of different ratios, so some components would have to be swapped in sets.