Anyone know anything about overdrive gearboxes ?

[danny allen]

Hi

I have an e reg ( mk3 ? ) transit 2.5D and its fitted with a 4 speed overdrive box, however the overdrive wire in the gear stick has been cut/broken. The wire has been lost and i wondered how to connect tis bck up?


Does on wire go to a live and the other to a swirched earth?

How do i use my overdrive?
Do i need to clutch it when im turning it on?

any help appreciated

thanks

dan

[FredTransit]

I have an OD box in a Mk2 minibus, and I don't know about installation, but the OD will not engage in 1st and 2nd, and you have to switch it in in 3rd or 4th, and switch it off when changing down. I am still getting used to the box myself, and occasionally forget to switch it off when changing down, it doesn't seem to have damaged it (yet!). To be honest I only use it on A roads and motorways and drive it as a 4 speed elsewhere as switching the OD on and off gets a bit much round town. Hope this helps.

[baconsdozen]

If you have a look underneath at the solenoid you should see if one of its wires is connected to earth.If it is the switch in the gear knob supplies a live feed which goes to the solenoid via cut out switches.The feed should be cut in 1st and 2nd gear and VERY importantly in reverse.If the vehicle is driven any distance at all in reverse with the OD engaged it will be smashed beyond repair.If in doubt pull the wires off the solenoid and subtitute a bulb,if it only lights in 3rd and 4th you should be OK.OD units are designed to engage and disengage with power going through them but it helps ensure long life if it is done with a low throttle opening and disengagement is carried out at relatively low speed to avoid over revving the engine.

[danny allen]

thanks for your help guys

it looks like there was once a wire from the gearknob, only the one though.

Would this be the earth?

[stevew]

There's usually two wires. In fact all that I've seen have used a piece of two core mains cable even the Ford fitted ones!
I don't have one myself so best to listen to someone else!

Steve

[danny allen]

mmmmm ill have another look at the weekend

[danny allen]

so do i change

clutch

1st

clutch

2nd

clutch

3rd

flick button on

flick button off

clutch

4th

flick button on



is that right guys?

[MrMPuk]

I never really see much point using the overdrive between 3rd and 4th.

[danny allen]

ok

its never worked on mine so i just wondered

[FredTransit]

I never really see much point using the overdrive between 3rd and 4th.

I only use mine in 4th too.

[bazw]

3rd od would be for those pesky hills where you cant quite run in 4th and rev to high in 3rd