Downchanging without synchromesh

[duncan_bayne]

Hi All,

I was wondering if anyone can share any tips for driving a Series II with no synchromesh on 1st and 2nd gears.

Going up through the box is easy now that I've got the hang of double-clutching up into 2nd. It's going down that's causing me (and I presume Rosemary) pain.

I've given up on selecting 1st while moving, after being so advised by the previous owner, so that's no bother. 3rd into 2nd though is essentially random ... sometimes it just snicks in to place, other times it goes in with a loud 'clack' and sometimes it just bounces around and refuses to go in at all.

I've never driven a car without synchro before so I don't really know how to approach this. Do I need to be in a certain rev / speed range to change down into 2nd? It's somewhat difficult to judge as the speedo needle swings around +/- 10MPH and there's no rev counter :eek:

Anyhow, thanks in advance for any advice ...

Yours,
Duncan Bayne

[TonyC]

The trick is double de-clutching.
When in third and needing to down shift, clutch in shift to neutral, clutch out, rev the motor just higher than would be needed for that speed in second, clutch in, select second clutch out.
If you get it all right then it just goes in if not it goes crunch.

It may take some practice.

Hope this is some help.

Tony

[Blknight.aus]

bout that...

the best way to get the concept is as follows

find a dead flat bit of side road with no traffic

drive along that road in second gear at say 35ish kph listen to the engine and watch how the terrains moving past you DO NOT look at the speedo. stop drive back to your start point


drive along the same bit of road in the same direction at the same speed in third and observe the same things. stop go back to the start point

repeat that, same direction same speed in third, push the clutch in put it in nuetral and then rev the engine till it sounds like it was in the first run then depress the clutch and quickly select second.

the concept you are after once you are in nuetral is to match the engine revs to the road speed for the gear you are about to select.

[Dougal]

Practise driving without the clutch.
When you've got that sorted (makes matching revs crtical) you'll find changing with the clutch to be an absolute luxury.:)

[russ55]

Mate- speed and revs. It's no good revvin the livin out of it to change down if you're going too fast. I can't remember the speeds but I do think the advice given by Blknight is a start. Don't worry about clunks. It's a tough box. Just worry about the grinds. When you change down at 15-20 kph, from 3rd to 2nd, try to feel the gear slipping in (no clutch) at different revs. You'll reach a sweet spot that will bring a revealation to you.

[JDNSW]

As above. My two sons learned to drive the 2a without great problems (no problem for me - after the model T the next two vehicles I learned to drive in had no synchro on any gears, and I had owned Series 1,2,2a in the sixties after driving one in vacation work in the late fifties).

Your advice to never engage first (or reverse) except when stopped is very good. The reason for this is that first and reverse are engaged by sliding gears, meaning only one tooth is engaged at a time, so that wear and damage from mismatched speeds is concentrated. Second gear is constant mesh, so it is engaged by a dog clutch, with the mismatch spread over about ten teeth at once. This is very tough, and damage is very unlikely.

The same applies to the transfer case - high range is constant mesh, low range is a sliding gear. Hence, there is almost no chance of damage changing from low to high if you screw up, but quite a chance of damage changing from high to low - don't try it until you are really expert at changing smoothly and noiselessly from low to high, and even then be wary - and there is almost nowhere where it is useful going from high to low.

Then when you are really expert, you can start split shifting - for example from low- fourth to high-second. And get even fancier if you have an overdrive! (but never use an overdrive in first or second - OK in low range third or fourth).

John

John

[wovenrovings]

The only thing i can offer is try it a low engine speeds to start with. I.e idleish speed in third and back to second. Then as you get better you will find it easier at higher rpm.
Then you can precede to hills or heavy ground. The thing you have to be aware of there is that the vehicle will slow down as you are changing gears, so it needs to be done quickly and the revs matched appropiately.

The whole process is about matching gear speeds. So when you rev it with the clutch engaged in neutral you trying to get the gears on the engine side to spin as fast as the gears being driven by the wheels. That way when depress the clutch you can just slide them together.

The only time i could ever get 1st to go in really nice was rolling along at idle in second and then is only needed a small blip of the throttle to go into first. I guess i didn't practise that enough. It is all about practise.

And a tip for when you are selecting first after being stopped with the clutch out. You know how it will grate a bit. Well stick it in 3rd gear first and then into 1st. The sycro on third will stop everything from spinning and 1st will engage without a sound.

Have fun.

[mike 90 RR]

random ... sometimes it just snicks in to place, other times it goes in with a loud 'clack' and sometimes it just bounces around and refuses to go in at all.

The one thing that gearbox will do ... is teach you how to change gears the proper way on a manual ..... and the lessons learn't will translate into excellent driving skills and gearbox changes on any rides that you own .....

Nothin worse than being passenger in someone's ride, and they whiplash your neck when they change gears .....

[Bushie]

The one thing that that gearbox will do ... is teach you how to change gears the proper way on a manual .....

Land Rover gearboxes in general will teach you that, they're not renowned for being smooth. :o


Martyn

[duncan_bayne]

Thanks for all the advice! :) I went for a long drive yesterday with my wife & practiced double-declutching downchanges into second, feeling the speed rather than relying on the instrumentation.

I'm now at the point where I only rarely get a grind with the downchange ... mostly it slots in, often with a positive-sounding clack (very different to a grind).

Amusingly, I got in the Terrano this morning to run my brother to the station and just about sent us through the windscreen by treating the disc brakes like Rosemary's drums ... :angel:

[Disco44]

As above. My two sons learned to drive the 2a without great problems (no problem for me - after the model T the next two vehicles I learned to drive in had no synchro on any gears, and I had owned Series 1,2,2a in the sixties after driving one in vacation work in the late fifties).

Your advice to never engage first (or reverse) except when stopped is very good. The reason for this is that first and reverse are engaged by sliding gears, meaning only one tooth is engaged at a time, so that wear and damage from mismatched speeds is concentrated. Second gear is constant mesh, so it is engaged by a dog clutch, with the mismatch spread over about ten teeth at once. This is very tough, and damage is very unlikely.

The same applies to the transfer case - high range is constant mesh, low range is a sliding gear. Hence, there is almost no chance of damage changing from low to high if you screw up, but quite a chance of damage changing from high to low - don't try it until you are really expert at changing smoothly and noiselessly from low to high, and even then be wary - and there is almost nowhere where it is useful going from high to low.

Then when you are really expert, you can start split shifting - for example from low- fourth to high-second. And get even fancier if you have an overdrive! (but never use an overdrive in first or second - OK in low range third or fourth).

John

John

G'Day John,
As one oldie to another your post bought back many memories re having to drive trucks with a "crash box".Once learnt never forgotten. How many times did you have to drive home with a "shot"clutch?
Cheers,
Another " John " (disco 44 )

[JDNSW]

G'Day John,
As one oldie to another your post bought back many memories re having to drive trucks with a "crash box".Once learnt never forgotten. How many times did you have to drive home with a "shot"clutch?
Cheers,
Another " John " (disco 44 )

Not too many, but probably the most memorable was driving across Brisbane in the evening peak hour in (probably) 1963 in my Series 2 with no clutch.

When I was first learning to drive at about age 11, my first was a Ford T, then a similar vintage Reo, with a three speed crash box with very widely spaced first and second, then a Swift with a four speed crash box, before getting my licence on an A30. Consequently, when I had to drive a Series 1 in a vacation job at Uni it did not even occur to me to think about the fact that it had sychro only on the top two gears.

John

[JamesH]

This is a great post and it's not an arcane topic either this matching revs business. I've seen how a 300tdi clutch fork can give up the ghost and choose beyond the black stump to do it.

Not to hijack a good thread or anything but do you see any advantage in double clutching in a modern synchro box? From 3rd down to 2nd in particular. I do it from time to time (mostly) and sometimes I imagine it works as it goes into 2nd completely "notchless". Am I imagining things and is it kinder to the works or does the synchro make the whole thing redundant and irrelevant?

[B92 8NW]

I wouldn't say its redundant - I occasionally doubled 3-2 on my LT77 and it went in far smoother.

[grounded]

double declutching is only for crash boxes.

do it with a synchro box and you will lessen it's life a lot.

[JDNSW]

double declutching is only for crash boxes.

do it with a synchro box and you will lessen it's life a lot.

I cannot visualise any mechanism where double declutching could possibly have any adverse effect on the life of a synchromesh gearbox. In fact, if anything, it would have a small beneficial effect by both minimising wear on the synchromesh cones and by usually reducing shock loading on the whole gearbox as done properly double declutching ensures that revs are matched when the clutch is finally engaged.

Similarly, it minimises wear on the clutch plate but has the adverse effect of doubling wear on the clutch withdrawal mechanism (although not on the release bearing). This last may be a significant factor on those gearboxes where there is a tendency to wear the clutch fork pivot point.

John

[Blknight.aus]

if you double declutch and get it right you extend the life of the syncros and the box.

do it and get it wrong however.......