2007 Elantra reverse gear.

This isn't a problem, I'm just kind of curious if this is normal.

My short driveway is slightly sloped up to the house. The car is
stickshift, and I sometimes start rolling backwards slightly while
pushing the clutch in and shifting into reverse. If the car does start
to move while I'm shifting, the gears grind. Is this normal?

I suppose there's no synchro for reverse, they probably didn't expect
people to be moving at all when shifting into it. I only ask because I
never had this issue with my 01 Elantra.

And to clarify my driving habits, on the occasions that this happens
I'm rolling all of about 2 feet. I'm not coasting downhill backwards
for any distance with the clutch in.

So, any thoughts?

Ben

 

All forward gears are helical cut (which means they are cut on an angle) and
have syncro rings to help guide the gears into place. Reverse gear is
straight cut and has no synrco as the car makers don't think you need to
engage reverse gear at speed. Although race gearboxes sometimes have all
straight cut gears as they are stronger but it takes a lot more skill to
change gears as the revs and the speed have to be right to make the gears
change to the next higher speed gear. Cheers Mate.

 

Used to call it double declutching when I learned to
drive. On a three cylinder diesel truck made by trojan.

 

The style of gears has nothing to do with shifting ease as almost no
modern transmissions actually move the gears to shift. Most are of
"constant mesh" design. The helical gears are used because they are
quieter in operation.

Matt

 

We just called it double clutching. I never heard the term double
declutching. Must be a regional thing.

Matt

 

Could be, common in the UK. Google gives several thousand
links.
Here is one from the BBC.
http://www.bbc.co.uk/dna/h2g2/A1011853

Double Declutching

Are you ever cruising along in fifth and suddenly you come across an
obstruction? You want to whizz past, but even changing down into fourth
won't give you the power you need. What's needed is a quick change down
into third or second gear. Doing this, however, runs a serious risk of
damaging your gear box. This is where double declutching1 comes in.

In ordinary declutching you use the clutch to change from a higher to a
lower gear. It's what you do all the time. Double declutching is a little
more elaborate:

* Push the clutch to the floor
* Put the gear lever into neutral
* Lift the clutch off the floor
* Give the accelerator a little blip to rev the engine up
* Push the clutch to the floor
* Put the gear lever into the desired gear
* Lift the clutch off the floor

Why do it? It puts the gearbox into an intermediate state where it is
better able to slip into the new gear, and matches the engine speed to the
new speed required by the lower gear.

The same process in reverse, but without the extra blip of the accelerator,
is used to go up to a higher gear. You'd do this when you've passed an
almost-stationary granny driver, for example.

 

I just googled and got 38,500 hits on "double clutching" and 11,100 on
"double declutching", so both are used a lot, but double clutching is
much more prevalent. Looks like a regional preference.

Matt

 

In the US, we don't usually use the "de" term. Double clutching is also
needed on older cars that don't have a synchronizer for first gear. It
allows you to downshift easily.

You can also use similar tactics, minus the clutch, to shift gears not using
the clutch at all. Going up is generally easier than going down.