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Replacing gearbox switch of the overdrive system

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BN6_2197

BN6_2197

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Gents, I have to replace the gearbox swith of the overdrive system. From my understanding it seems to be a simple task even if the gearbox is in the car: detaching the two electric wires, remove the old swith, screw in the new one and attaching the wires again. Is that righ? Do I have to pay attention to what so ever?

Regards,


Volker
 
BN6_2197 said:
Gents, I have to replace the gearbox swith of the overdrive system. From my understanding it seems to be a simple task even if the gearbox is in the car: detaching the two electric wires, remove the old swith, screw in the new one and attaching the wires again. Is that righ? Do I have to pay attention to what so ever?

Regards,


Volker
Click to expand...

That's it in a nutshell. That is assuming you already have the interior out. I don't think there's any way to loosen the screws to disconnect the wires on an original type switch with the tunnel in place. The replacement switches have push on connectors.
 
Last edited:
Jack T said:
That's it in a nutshell. That is assuming you already have the interior out. I don't think there's any way to loosen the screws to disconnect the wires on an original type switch with the tunnel in place. The replacement switches have push on connectors.
Click to expand...

My hope was that I can replace the switch from under the car without the need to remove the interior and the tunnel. It is looking like this currently.

A623BEBE-C686-4C11-9A7A-AAB6C658D893.jpeg
 
Looks like you have the newer style switch with push-on connectors already, so you should be good to go. I found that one of my switches was so close to working or not that if I left out the fiber washer it worked, with it in it did not. I smeared the threads with sealant and left the washer off.
 
Just curious...how did you determine that your switch needed to be replaced? The reason I ask is that I have had issues with OD engagement and in an effort to troubleshoot the problem, I found that the solenoid does not click with the ignition on, dash switch on and gear lever moved to either 3rd or 4th. Good to know that the switch can be replaced from below.
 
Can anyone tell me if it is necessary to drain the transmission oil in order to replace the gearbox switch? Thanks
 
After getting the overdrive working on the BN4 last week, I felt like I was on a roll. So I went after the non-operational overdrive on the BJ7, a partial restoration that I finished a couple of years ago. The drive train was in the car, although all the body panels, interior, and trim were off of it when I got it. Although the car was repainted and reassembled, it bugged me that the overdrive did not work.

The third reason why the overdrive did not work involved the Overdrive Switch, which I replaced today. Interesting how Healey mounted the Gearbox Switch externally on the center shift BJ7, compared to how it mounts on the earlier side shift cars. That makes it easy to see how it works. The switch still made contact to complete the circuit, sort of; the gear shift lever had to be pushed sideways a bit in 3rd and 4th to make it engage and there was no adjustment left.

That was after setting the Throttle Switch, which was way out of adjustment. And whoever installed the overdrive solenoid just dropped the new plunger in from the top, instead of taking the cover off and fitting it into the right place.

Overall, not a difficult fix. Just glad that the unit did not have to come out.

Three reasons why the overdrive did not work. Now it works fine.
 
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