[Mgs] Determine build date for an O/D transmission?
Charley Robinson
Charley38 at twc.com
Mon Nov 11 11:56:01 MST 2019
That might be handier than the stalk switch in my '69. I'm not a fan of
running wires down a gear lever & through the tunnel. Just don't like
the potential for fraying the wires.
CR
On 11/11/2019 11:32 AM, Max Heim wrote:
> Exactly. I have a 1977 vintage blue label OD transmission in my 66. I
> have a dash-mounted switch to the left of the steering column. The
> wiring couldn’t be simpler. No weird expensive parts. The straight (as
> opposed to crookneck) dash OD switch is cheap.
>
> You might not think the dash switch is as convenient as the gear lever
> switch, but it is really pretty ergonomic. You can flick it with the
> side of your hand while it is still in contact with the wheel — you
> don't have to go groping for it.
>
> --
> Max Heim
> '66 MGB
>
>> On Nov 11, 2019, at 8:08 AM, Charley Robinson via Mgs
>> <mgs at autox.team.net <mailto:mgs at autox.team.net>> wrote:
>>
>> I've swapped OD gearboxes into two CBBs. In both cases I used the
>> gear levers from the original non-OD transmissions. I don't see any
>> reason that you can't use the gear lever you already have for the OD
>> box.
>>
>> As to the OD switch, I'd put it on the dash if I had an open spot for
>> it that was handy to my right hand. In the CB cars the wiring and
>> switch are already installed but there's no reason you can't find the
>> white circuit that Paul mentioned and run a wire from it to your
>> switch and from the switch to the lockout switch on the OD box.
>> Looks like there are a couple of switches in the Moss catalog that
>> would look OK on the dash. The switch is just a SPST that can handle
>> the solenoid current.
>>
>> My $ .02,
>>
>> CR
>>
>> On 11/11/2019 7:35 AM, Andrew Lundgren via Mgs wrote:
>>> I have a '78. The transmission is a blue label, but the seller
>>> doesn't have the shift lever.
>>>
>>> A lever for a '78 is not a cheap thing, and my son who is driving it
>>> a lot right now likes the Walnut MG logo shifter it has. So I'm
>>> looking at options for how to install the O/D switch.
>>>
>>> From the moss catalog, it looks like the '76 switch won't work with
>>> the '78. So I might have to buy the parts to put together the
>>> shifter switch or put it in the blank accessory switch above the fan
>>> on the dash.
>>>
>>>
>>>
>>> On Mon, Nov 11, 2019, 1:45 AM PaulHunt73 <paulhunt73 at virginmedia.com
>>> <mailto:paulhunt73 at virginmedia.com>> wrote:
>>>
>>> None of that is to do with the OD itself.
>>> Which gears it operated on is a function of the linkages on top
>>> of the gearbox, and you can have it on 3 and 4 or 4 only as you
>>> wish. When the TCSA was introduced in late 76 to control
>>> 'surging' a third switch was added to the top of the gearbox
>>> that operated in 2nd and 4th, and this was wired in series with
>>> the OD switch operating in 3rd and 4th to produce a 4th gear
>>> only output controlling the TCSA and vacuum advance. I suspect
>>> that was not very reliable as it was an external micro-switch so
>>> it was deleted and the gearbox components changed so the switch
>>> operated in 4th only, as done to the V8 several years
>>> previously. The gearbox switch now controlled both OD and TCSA.
>>> The gear lever itself changed for the 77 model year to
>>> incorporate the OD manual switch, but that can also be fitted to
>>> any year, or the 77 converted back to some other switch, as you
>>> wish.
>>> The wiring prior to 77 was from the manual switch on the dash or
>>> the column, to the gearbox switch on a yellow and a yellow red,
>>> then from there to the solenoid. For 77 on it was from the
>>> ignition supply on a white to the gearbox switch, then from
>>> there to the manual switch on the gear lever, and from there to
>>> the solenoid.
>>> Black label or blue label determines which speedo is compatible
>>> - black label was used on CB cars and used a 1280tpm speedo.
>>> Blue label was used on RB cars and used a 1000tpm speedo. But
>>> speedos can be recalibrated if you end up with the wrong
>>> combination.
>>> So as a 78 it should have a blue label OD and the manual switch
>>> on the gear lever, as the column switch - which together with
>>> the plastic dash was new for the 77 model year - won't have that
>>> function. But if the car has the earlier RB dash and column
>>> switches you don't need the gear lever switch, which is prone to
>>> shorting out and causing harness damage.
>>> PaulH.
>>>
>>> ----- Original Message -----
>>> Not so much. It will be a a bit still until the transmission
>>> arrives. (Freight from NY to UT) I'm just trying to figure
>>> out which shifter it should have had as well as which gears
>>> it should work on.
>>>
>>> I'm going to be putting it into a 78, but the current owner
>>> is still trying to track down the shifter from his friend,
>>> the previous owner. He doesn't know if it was a late shifter
>>> or an early one.
>>>
>>> I'm trying to determine how to wire it in.
>>>
>>>
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>>
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>>
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