TR2/3/3A Downshifting Technique

I'm interested in the proper downshifting technique to use when driving along in 3rd or 4th gear and are approaching a red light. Also, do you keep it in neutral at the light? My car seems to be stalling at lights and stop signs and I think its my technique. Thanks.

Art

I never down shift unless it is ABSOLUTELY necessary, for a few reasons. Brake pads are cheap and easy to replace. Syncros are a little more expensive and much more difficult to replace. I don't like loading the engine up from the wheels because you increase the chance bending a push rod that way. Also, it's more efficient from a fuel stand point.

That being said, if you come off the throttle and your car dies, you may have a dashpot oil problem, either not enough or too light weight. Check there first.

Lastly, every time you push the clutch in, you load the thrust washers on the crank. These are a wear item and there is no need to wear them if you don't have to. I do not put my foot on the clutch without good reason. I don't push it to start to car or hold it down at a stop light.

Thrust washers are a common problem on the later motors, that have only half as much thrust bearing surface as the TR2-4 motor does, but I've never seen or heard of a problem on a TR3. Mine weren't too badly worn even on the engine where the rod bearings were worn all the way into the steel backing (previous owner apparently didn't believe in oil changes). I use compression braking frequently and I've never worn out a thrust washer or bent a push rod. Synchro rings I have worn out, but only after a lot of miles. (Got perhaps 150,000 on the current set, guess I should have changed them when I had the OD apart last.)

But, using compression braking does make the engine more apt to die, because the cylinders and spark plugs cool off and possibly even load up a bit with unburned fuel. The engine is basically just barely running if at all (which is why exhaust emissions are so high and many emission setups include a means to hold the throttle open a bit to keep it running or else add plain air to make sure it doesn't).

So if it dies like that (and mine does at the moment), I take that as an indication that it needs a tune-up. New plugs, points condenser; plus adjust the ignition timing, valve lash, and idle mixture. Also check that the carb pistons move absolutely freely (except for the action of the dashpot of course) and land with a distinct click. If they are dirty or the jet centering isn't perfect, that will also make it want to die sometimes.

As a side note, I've discovered that on the carbs I'm using, the dome-to-body fit is loose enough to mess up the jet centering if I R&R the domes. So now I install all 3 screws loosely, then turn the dome clockwise for final tightening, so it always returns to the same place.

If you've been through all that and it still wants to die, you may need a little bit higher idle rpm. Almost any sort of engine modification, like larger liners, more compression, lighter flywheel etc will need a bit more to keep it running. (I have all 3 of those.) The engine I had before with the "3/4 race" cam didn't like to idle below about 1500 (and was a bit lumpy even there).

" I don't like loading the engine up from the wheels because you increase the chance bending a push rod that way. Also, it's more efficient from a fuel stand point. "

Hi Could you explain to me how this works, not familiar with this .

Doug

The most frequent reason I downshift is when making a turn and needing a lower gear to come out of it, never when I plan to come to a complete stop. I always put the gearbox in neutral at a standstill (like a stoplight) not for the thrust washers but to minimize the work the throw-out bearing gets. Wouldn't matter if (like my wife) you only keep the car for 20 years or so but I'm in it for the long haul.

Not sure there is any "prescribed technique" other than down shifting to a lower gear when RPMs drop to the point that it would "labor" the engine when making a turn. A lot of the down shifting with me depends on how much fun I'm having on curvy roads. Down shifting when coming to a stop...to slow the car... isn't necessary, but is sometimes fun. If all the things that Randall mentioned are in order and your car is running properly, you might just need to raise the idle a little. Not many cars without fuel injection and a computer will idle CONSISTENTLY at 650 RPMs.

Thank you all for your help. I did increase the idle and adjusted the timing a bit, took it for a ride and there was no stalling. The tune up parts were replaced fairly recently, although I have not had the valve lash checked. I still have situation where the tachometer needle tends to fluctuate up and down a bit. Not sure if that is just because its a 50 year old tach or a sign of something else.

Art

The Car Guys answered the question some years ago - "What's cheaper - a set of brake linings or a new transmission?" Except on the race track, I have never downshifted to slow the car down. Never had any transmission trouble either.

pdplot said:

The Car Guys answered the question some years ago - "What's cheaper - a set of brake linings or a new transmission?"

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Of course, that depends entirely on how many sets of brake linings you get per transmission.

I drive a TR because it's fun, not because it's cheap.

Man, what a bunch of granny-shifting old ladies. You're driving a sports car, not a 1962 Plymouth Valiant with a slant six and three on the tree. One of the joys of sports car driving is learning to drive a manual transmission properly,which includes how to execute a heel and toe downshift while correctly matching engine revs without damaging your synchros. Using engine braking to slow going into a corner while being in the correct gear to exit is so rewarding. The sound of a highly tuned motor as you blip for a downshift is music. I've driven my cars like this for almost 50 years and have never had a transmission failure. And even if I did, it would be totally worth it.

Lot of responses worried about the tranny. You guys have heard of double clutching? Learn the technique and you put no strain or wear on the tranny. Just because a box has synchronizers doesn't mean you have to let them do all the work. The technique also reduces the shock on the drive line and clutch wear too. Once you get good at it you don't even consider a "granny" downshift.

Well, whatever technique you wish to employ while driving these fun old cars, just don't learn it watching/listening to the chase sequence in "Bulllitt."

TRMark said:

Well, whatever technique you wish to employ while driving these fun old cars, just don't learn it watching/listening to the chase sequence in "Bulllitt."

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I always wondered why it sounded like he was double-clutching on upshifts during the chase. Turns out they dubbed in the sound of a Ford GT40 with a non-synchro 5 speed in for parts of the film, which explains the double clutching.

Perhaps I should have qualified my "Never". I meant when slowing for a red light. I have downshifted many times when driving on a back road especially in a convoy of sports cars. I never bothered double clutching except on my 1934 Ford; in fact I have driven many 4-speed cars shifting without the clutch - up or down with nary a grind (well maybe once or twice on certain cars when the speeds didn't match up). Easier on some cars than others. Once, out of necessity, I drove from Philly to CT without using the clutch when the fluid leaked out of the hydraulic clutch m/c on my Lea-Francis MG umpteen years ago. Fun when I stopped at a toll booth or a red light. I put the car in neutral, stopped, paid the toll, put the car in first and cranked it over to start it again.

HealeyRick said:

Man, what a bunch of granny-shifting old ladies. You're driving a sports car, not a 1962 Plymouth Valiant with a slant six and three on the tree. One of the joys of sports car driving is learning to drive a manual transmission properly,which includes how to execute a heel and toe downshift while correctly matching engine revs without damaging your synchros. Using engine braking to slow going into a corner while being in the correct gear to exit is so rewarding. The sound of a highly tuned motor as you blip for a downshift is music. I've driven my cars like this for almost 50 years and have never had a transmission failure. And even if I did, it would be totally worth it.

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Thank you...Marla

pdplot said:

...Once, out of necessity, I drove from Philly to CT without using the clutch when the fluid leaked out of the hydraulic clutch m/c on my Lea-Francis MG umpteen years ago. Fun when I stopped at a toll booth or a red light. I put the car in neutral, stopped, paid the toll, put the car in first and cranked it over to start it again.

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Been there, done that on two occasions. Once with a '62 TR4 (my first Triumph) for about a 60 mile run, and again with a VW Rabbit for a much shorter distance of just a few miles. Every now and then, I use the "no clutch" technique for up and down shifts in my TR3 and Miata just because it's so satisfying. BTW, I find downshifts without using the clutch are much easier then upshifts. Just snick it in neutral, rev the engine, put a little pressure on the stick going into the lower gear, and when the revs are matched up the shifter literally gets sucked into the lower gear without any fanfare. Very rewarding.

Ditto, tho not recently. My previous "family car" had a habit of breaking clutch cables, so I limped home more than once with no clutch. Haven't had to do it on a TR tho, since that time I put the wrong TOB in and it failed. Lots of fun, trying to creep up the on-ramp to the freeway with no clutch! (Around here, when traffic gets heavy, they use "meters" that only allow one car at a time onto the freeway. So you can wind up spending several minutes waiting in line for the meter to turn green.)

There was also that time back in the 70s, a friend of mine and I took a road trip together. He was going someplace in Charlotte, NC (I think it was) and I was trying to follow him (had no idea where we were going). Bolts fell out of the slave cylinder, so I was desperately trying to keep up, and flashing the headlights every chance I got to flag him down. But he was busy looking for the place and didn't notice. As I recall, he never did find the place

Could be worse. I drove an antique school bus for awhile (1958 White) that had no synchromesh at all, so you had to double-clutch every gear change. It was also a "pusher", so the shift rods were some 50 feet long! Had this gigantic flat head 6 that hung out behind the rear axle. Met my first wife while driving that bus, shame it had to go to the scrap yard.

CJD said:

Lot of responses worried about the tranny. You guys have heard of double clutching? Learn the technique and you put no strain or wear on the tranny. Just because a box has synchronizers doesn't mean you have to let them do all the work. The technique also reduces the shock on the drive line and clutch wear too. Once you get good at it you don't even consider a "granny" downshift.

Click to expand...

Thanks for reminding about double clutching, it's been so long I had forgotten.

Hope you figured out down shifting. I thought about your post as was surfing on you tube and found this series on racing and this link is about down shifting . If the link doesn't work go to I racing down shifts in the search block. Hope this helps. https://www.youtube.com/watch?v=x_e2Ztnuamg Then entire series is great too.

Ditto, Rick!
"Not-shiftless" Bob