MR2 2002 6 speed

[feralcheral]

Hi

I am new to the club

I have a MR2 convertable 6 speed 2002 model

I have had it for 3 weeks, is it normal to hear a clunk in the gear change when it is changing down from 2nd to 1st

Any help appreciated

Feralcheral

[the_random_hero]

To an extent, yes. 1st will normally be without any synchro's, so this will sometimes happen when downshifting. If you're doing it to come to a stop, you're much better staying in second as it's better for your gearbox.

If you're worried get a mechanic to take a look at it. All it may need is a simple fluid change.

[Hiro]

To an extent, yes. 1st will normally be without any synchro's,

I most certainly hope not, gearboxes have been fully synchronised for well over 20 years (if not 40).

Edited May 21, 2009 by Hiro Protagonist

[the_random_hero]

To an extent, yes. 1st will normally be without any synchro's,

I most certainly hope not, gearboxes have been fully synchronised for well over 20 years (if not 40).

Interesting, when I was asking about my box being a bit clunky going into 1st, I was told by a mechanic it's because 1st doesn't have synchro as it's normally not really needed...

[Hiro]

To an extent, yes. 1st will normally be without any synchro's,

I most certainly hope not, gearboxes have been fully synchronised for well over 20 years (if not 40).

Interesting, when I was asking about my box being a bit clunky going into 1st, I was told by a mechanic it's because 1st doesn't have synchro as it's normally not really needed...

It's clunky going into first because the synchros will be worn - first gear is the one that gets affected most because it's the biggest torque multiplication, and it's the gear that gets abused most (stop-start traffic, lots of shifting)

Your mechanic might be used to dealing with American transmissions in Holdens etc (which were generally very old basic designs and didn't have synchromesh on first), like how some dyno operators say that 4th gear is always 1:1 because it locks the input shaft directly to the output shaft (complete crock of **** in FWD Toyota gearboxes) because most of their knowledge is in RWD transmissions like Toploaders and Tremecs.

Edited May 21, 2009 by Hiro Protagonist

[the_random_hero]

To an extent, yes. 1st will normally be without any synchro's,

I most certainly hope not, gearboxes have been fully synchronised for well over 20 years (if not 40).

Interesting, when I was asking about my box being a bit clunky going into 1st, I was told by a mechanic it's because 1st doesn't have synchro as it's normally not really needed...

It's clunky going into first because the synchros will be worn - first gear is the one that gets affected most because it's the biggest torque multiplication, and it's the gear that gets abused most (stop-start traffic, lots of shifting)

Your mechanic might be used to dealing with American transmissions in Holdens etc (which were generally very old basic designs and didn't have synchromesh on first), like how some dyno operators say that 4th gear is always 1:1 because it locks the input shaft directly to the output shaft (complete crock of **** in FWD Toyota gearboxes) because most of their knowledge is in RWD transmissions like Toploaders and Tremecs.

You learn something new every day :)

[Tiang]

it could be the hydraulics going clunk as they move the gear shifter into 1st gear. no problem AFAIK.

[httttt]

Are you putting your car into 1st while rolling?

If so, then I'm pretty sure that is a big no-no (someone back me up or shoot me down).

[MR22ZZ]

I'm assuming this is the semi-automatic transmission model and not a JDM manual 6-speed.

Have you checked the transmission oil lately, may also be worth dropping the tranny oil pan and seeing if there is any debris in there.

Fresh tranny fluid can smooth things out most times.

[Hiro]

I'm assuming this is the semi-automatic transmission model and not a JDM manual 6-speed.

Have you checked the transmission oil lately, may also be worth dropping the tranny oil pan and seeing if there is any debris in there.

Fresh tranny fluid can smooth things out most times.

Aren't they sequential C-series manual gearboxes and not semi-autos?

[MR22ZZ]

nope, manual ZZW-30s were never sold in Australia

[SuperDave]

I thought the sequential auto (in the zzw30) was just a manual box with some hydraulics slapped to it to operate the clutch and change gears for you...

nope, manual ZZW-30s were never sold in Australia

Which is uber ghey

[Hiro]

nope, manual ZZW-30s were never sold in Australia

I know that true manuals weren't sold here, but the gearbox we got was a sequentialised and clutchpedal-less C-series manual box, not a semi-auto.

I thought the sequential auto (in the zzw30) was just a manual box with some hydraulics slapped to it to operate the clutch and change gears for you...

Exactly the impression I had. The gearbox code was something like C56M (I know the 6-speed sequential is a C65/66M)

[MR22ZZ]

ahhh, furry muff :)

[terryo]

the downwards clonk is not likely to be syncros. those boxes have terrible syncro problems, but mostly in 2nd & 3rd.

the clonk into first is possibly in the drive axles, but more likely to be associated with the SMT controller. before you waste any time on worrying about it, keep a log of EXACTLY what it does right/wrong/"funny" for at least a week, then pay a professional to review that and check it for fault codes and if necessary, follow the re-learn procedure. That person will need a scan tool.

I can confirm it is internally a conventional corolla manual box. almost the same as Celica/Sportivo 6 speed. The SMT stuff is external. I've fixed a number of these boxes