How to use overdrive properly

[Ukpooky]

I will caveat this as a potentially stupid question but it's from someone who is yet to drive a Stag...

How do you actually use the overdrive on a manual car?

So it's a switch on the gearstick that works on 3 and 4 - you go up 1 - 2 - 3 - 4

when do you engage the overdrive?

between 3 and 4 (like a 3.5?) or you go 3 then 4 then 3 overdrive then 4 overdrive?

does it turn off automatically when you change down or do you have to turn it off?

can you accidentally stick it on in reverse and blow everything up or it just wouldn't engage?

Imagine a 10 year old asked you 'when do you push that switch Dad' ...!!

Is there actually a right/wrong way to use it, or is there a bit of personal preference?

[Tdafforn]

Hi
I don't think there is a "right" way. I have OD on both my TR (opperates on 2/3/4) and Stag (opperates on 3/4)
on the stag I use OD4 when cruising and I flick in and out of OD3 when driving through town (saves changing gear and the RV8 will pull from almost walking pace in 3rd)
In terms of sequence I generally go 1/2/3/4/OD4 when getting up to speed. There is little use in adding OD3 to that sequence as it is close to 4th
(I have an OD logic system on my TR which knocks the OD off when I change gear which removes that slightly embarasing situation when you drop from OD4 to 3rd to overtake and get OD3 instead which somewhat blunts your acceleration)
Cheers
Tim

[singapore stag]

Do you have to ease off the gas paddle to engage O/D and vice versa

[DJT]

Do you have to ease off the gas paddle to engage O/D and vice versa

No.

[Paul Kelley]

For all practical purposes you can regard it as a fifth gear, that is 4th + Overdrive. It is designed to engage with some power on, so you don't lift off the throttle or use the clutch to engage it or disengage it (much as with modern bicycle gears). You simply change up to 4th gear, have a minimum of around 2,000 rpm or more and switch it on. You disengage it by switching it off - again, smoother if you have some throttle on - and return to 'normal' 4th gear (and 3rd gear). If you don't switch it off you will remain in overdrive mode for both 3rd and 4th gear making them 'taller' than standard setting. Hope that helps, it's a fair question if you've never come across overdrive. Some people, younger than me, think that it's 'pretty cool'!

[stag8manod]

Overdrive is engaged with power on, I disengage on a trailing throttle. My OD works on all 4 forward gears although i don't use 1st OD. 2nd OD is useful around towns not so much on the open road. I run a 3.45 S diff behind the J type OD which means it is quite highly geared and the OD gets a lot of use. For quicker acceleration, passing, full throttle switch OD out and she will pick up her skirt and fly.
Cheers Ian A

[Rigid]

I use OD3 when pootling around town etc, when changing up to 4th seems too much.
I can then switch the OD on and off as the need arises without having to touch the clutch.
(my gearbox does occasionally refuse to drop from 4th to 3rd with perhaps a tired synchromesh so doing this avoids embarrassing crunches)
Perhaps I need to learn to double-de-clutch.

[StagJonno]

I was told that the O/D couldn't cope with the V8 torque in 1st & 2nd, which is why as standard, it's restricted to use on 3rd & 4th. Makes sense to me, though if you're only on a light throttle, you'll probably get away with it in 2nd.

I find if I forget to switch the O/D (J-type) out before changing gears, I get a bit of a crunch going from 4th to 3rd. I think, if the gear lever was moved to N for a second or two, the O/D will drop out anyway, but that's not my normal driving style

[singapore stag]

I was told that the O/D couldn't cope with the V8 torque in 1st & 2nd, which is why as standard, it's restricted to use on 3rd & 4th. Makes sense to me, though if you're only on a light throttle, you'll probably get away with it in 2nd.

I find if I forget to switch the O/D (J-type) out before changing gears, I get a bit of a crunch going from 4th to 3rd. I think, if the gear lever was moved to N for a second or two, the O/D will drop out anyway, but that's not my normal driving style

You seem to ' know your onions ' about classic cars and technical matters. Are you or have you been an Engineer by trade?

[Tdafforn]

I've also had a slight crunching when changing with od engaged in my tr6. I wondered if there is some form of backlash when it engages and disengages

[richardthestag]

I do lift the throttle when engaging j-type overdrive in either 3rd or 4th as it seems to jolt a whole load less.

I did read somewhere that a-type overdrive needs a clutch depressed but maybe dreamed that or just confused it with the land rover mechanical laycock (oopsie Fairey) over drive systems which do need clutch to allow the change.

Regarding overdrive in 1st and 2nd, I believe that the only reason it is not available is because the inhibit to protect reverse gear and potential OD damage would be way more complicated, hence it being on the 3rd/4th selector rod only. Cheap and easy solution and also overdrive 1st might make you stall, especially if like me you are running 2500 3.45:1 diff.

Overdrive unit is pretty tough as ex non-member dtph explained. Anyone fancy sponsoring me to disable the inhibit and light up a rear wheel in 1st gear pull away with overdrive engaged?

As has been mentioned above already by rigid, 3rd gear (driving in a 30MPH ZONE) in and out of overdrive is perfect. else it is 1-2-3-4-4od for me

[DJT]

I did read somewhere that a-type overdrive needs a clutch depressed

Not necessary on the Stag A-type. I did 60k hard driven miles in my first Stag (Mk1) and never used the clutch when switching in or out of OD, or backed off the throttle.

[singapore stag]

I came across this from a contributor to a classic car club in the USA.

" You do not have to use the clutch to switch into overdrive. An overdrive is basically a single planetary gear set that is engaged by a hydraulic clutch triggered by the solenoid activating. Using the manual clutch is redundant "

[stag8manod]

I don't use OD heavily in 2nd gear, light throttle usually around town. The OD is still protected from reverse.
Cheers Ian A

[Motorsport Micky]

Maybe the wrong forum to mention it, but if you are cornering "on the limit" not necessarily because you are pushing the car on but going downhill...in the wet...around a curve...and even worse on an adverse camber, if the overdrive is deselected and you don't judge the revs correctly so it is completed smoothly, it can cause a momentary "snatch" at the rear wheels enough to exceed the tyre coefficient of grip and give you some "exciting" moments.

Micky