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TR2/3/3A Overdrive help.

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M

Momikey

Senior Member
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Hello,
I just got a 1958 Triumph Tr3a 4 speed. It is all new to me so I have many questions but I will start with how do I use the overdrive. Right now the switch is at the top is that on or off and what order is it going down? When should it be on and when should it be off? This may sound like a dumb question but I inherited this car from my uncle and I have never had any experience with them before but I love the car and I am trying to learn as much as I can to keep the car going for many years to come.
 
Welcome! Well you will have no problem with that positive attitude and it's great you love the car - you will enjoy it even more as you drive it.

normally, I think the switch is off when up and on when down. You don't need to clutch when you engage it - just try it out in Third or fourth gear it should be noticeable when you flick the switch up and down.
 
Hello. Thanks for answer. So do I flip it down when I shift or do I flip it down to a position and leave it there? Is there more then one position or just on and off?
 
TR4nut said:
...I think the switch is off when up and on when down...
Click to expand...

Like British light switches (opposite of the US).

Personally I generally use the clutch when engaging or disengaging the OD - just seems 'kinder' though I know it is not necessary.

Think of it as a 7 speed gearbox where, in addition to the usual 4 speeds you now have access to 2½, 3½, and 5th.

3½ (3rd with OD) is often just right for climbing mountains. 5th is great for cruising the highway at speed. I rarely use 2nd OD.

Something you might want to do is sit in the car with the ignition on and engine off (assuming you don't have a Pertronix or other electronic gadgets that won't like this) and try flicking the switch in various gears. You can hear a distinctive 'click' when the OD engages. This isn't just for fun, it also lets you easily confirm that the OD can only be engaged when you are 2nd, 3rd or 4th. There are lock out switches to prevent engagement in 1st and reverse. You want to be sure they are working correctly as damage can ensue if they do not and you drive like that - especially if they allow engagement in reverse.

IOW - with the OD on as you shift thru the gears you'll hear that click only when you go into 2nd, 3rd and 4th - not when you go into 1st or reverse. As you shift the OD should drop out each time you go into neutral - that's why you'll again hear a click as you change, say, from 3rd to 4th.
 
It is completely separate from shifting...like an "extra" gear. Usually wait until you are in 4th, and then use it like a 5th gear for better mileage on the highway. Or...if you like playing, go 3rd, 3rd OD, 4th straight, and 4th OD. Some granny's will allow 2nd OD too.

Once you start driving with it it will make sense to you.
 
Thanks guys. Ok so do I turn it on when I start the car and just leave it on and then turn it off when I park or do I have to flip after I'm in gear and then in flip it before I down shift?
 
I was remiss - I went straight to an answer without saying 'welcome and congratulations on getting a TR3A'.

Photos are always enjoyed so post some if you feel like it, but mostly just drive & enjoy.
 
Ok so do I turn it on when I start the car and just leave it on and then turn it off when I park or do I have to flip after I'm in gear and then in flip it off before I down shift?
 
You can do that, but I wouldn't suggest it as a rule. You'll start in 1st direct, then depending on how well your OD builds and holds pressure; either go directly to 2nd OD or get a few seconds of 2nd direct followed by 2nd OD. Won't hurt the OD, but feels funny especially if you aren't going very fast when you shift to second.

At least initially, until you are more accustomed to how it works; I suggest leaving the OD off until you are up to cruising speed. Then push the clutch and flip the switch to get top gear.

Later, you can learn to do more (like shifting under power) but start with the basics.

The switch can be assembled either way, so you'll need to figure out how yours is wired. My previous TR3A was wired down=off, and I've just kept that way ever since.

(Strange. I know my profile is set to show my signature, but it appears to not work when I post through this phone. Does anyone else see it?)
 
Watch your tach and you will notice a lower RPM's when the OD is engaged. Also, you must never put the car in reverse if the OD is engaged or you will damage the OD. It should not engage if you are in reverse but if the lockout switches fail you could still be in OD and not know it. This has happened to me twice in my Healey. When you disengage the OD watch the RPM's so you are SURE it has disengaged. Have a good day!

John
 
Slightly off the topic, Randall, but look out. I bought another TR, my third, and it has an A-Type OD. I'll be rebuilding it, just like the other one, after restoring the front end and frame, steering and suspension. You might remember answering questions for me all night and day. Sometimes I had a real problem around midnight, and you were still up and around and talking. I remember all the fantastic and detailed advice you gave me, all memorialized here on this Board, everything from the operating valve and sliding clutch, to the internal piston and springs, to the pump, bearing fittings and end float. I remember how I showed my deep gratitude for all your time and effort, sharing all your knowledge and advice, by saying things like "Thanks Randall."
 
Thanks that a good way to know.
John_Progess said:
Watch your tach and you will notice a lower RPM's when the OD is engaged. Also, you must never put the car in reverse if the OD is engaged or you will damage the OD. It should not engage if you are in reverse but if the lockout switches fail you could still be in OD and not know it. This has happened to me twice in my Healey. When you disengage the OD watch the RPM's so you are SURE it has disengaged. Have a good day!

John
Click to expand...
 
Lol yes I have.
It's been awhile but it was just like riding a bike.[
QUOTE=CJD;1014877]Starting from the basics...have you driven a stick before?[/QUOTE]
 
Momikey said:
Lol yes I have.
It's been awhile but it was just like riding a bike.[
QUOTE=CJD;1014877]Starting from the basics...have you driven a stick before?
Click to expand...
[/QUOTE]

Then you have to think of the OD as just an extra gear. Just like you would not start driving in 2nd gear from a stop, you should not start in OD from a stop. OD is intended to give better mileage once you are up to speed on the highway. That is it's sole purpose from the factory...hit high gear on the freeway and THEN engage the OD. The stock TR3 actually goes just as fast in 4th without OD...so it is really just for economy, not performance.

That was the factory...operators have different ideas. Owners and racers wanted to be able to engage OD in other gears than 4th, so the factory complied. That allows you to pop into OD in 2nd, 3rd, or 4th. In the end, if you enjoy flipping the switch up and down on every shift, you can (in theory) have 7 usable forward gears. In reality the ratios are not quite right to make it useful for anything other than the fun of flipping the little switch and feeling the Whoosh as the OD hits.
 
Cool thanks.

Then you have to think of the OD as just an extra gear. Just like you would not start driving in 2nd gear from a stop, you should not start in OD from a stop. OD is intended to give better mileage once you are up to speed on the highway. That is it's sole purpose from the factory...hit high gear on the freeway and THEN engage the OD. The stock TR3 actually goes just as fast in 4th without OD...so it is really just for economy, not performance.

That was the factory...operators have different ideas. Owners and racers wanted to be able to engage OD in other gears than 4th, so the factory complied. That allows you to pop into OD in 2nd, 3rd, or 4th. In the end, if you enjoy flipping the switch up and down on every shift, you can (in theory) have 7 usable forward gears. In reality the ratios are not quite right to make it useful for anything other than the fun of flipping the little switch and feeling the Whoosh as the OD hits.[/QUOTE]
 
OD is intended to give better mileage once you are up to speed on the highway. That is it's sole purpose from the factory...hit high gear on the freeway and THEN engage the OD.\
Click to expand...
Which I guess explains why the factory went out of their way, even modifying the OD, to make it operate in 2nd and 3rd gear.
The stock TR3 actually goes just as fast in 4th without OD...so it is really just for economy, not performance.
Click to expand...
Well, I guess there's stock and then there's stock. But all of my TRs, even the ones pretty close to stock, pick up some top end with the OD working. 5000 rpm in 4th direct or 4700 in 4th OD, you do the math.

And splitting the 2-3 shift will definitely shave a tenth or two from the 0-60 time if you do it right.

In reality the ratios are not quite right to make it useful for anything other than the fun of flipping the little switch and feeling the Whoosh as the OD hits.
Click to expand...
You've never driven a twisty mountain road in a TR with a working OD, have you ?
 
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