RXXX8

does anyone have problem shifting very fast into 2nd gear or downshifting at high speeds from 3rd into 2nd? by problems i mean do the gears make a crunching noise as u shift either up or down?

timbo

Yes... I think a few people have mentioned this. It's hard to nail a good 1-2 shift, but the RP short-shifter helps....also with the sometimes troublesome 5-6 shift

takahashi

WPNRX8,

Please ignore the other thread, I am trying to be serious here.

There is a lot of people have difficulty shifting down from 3rd to 2nd. I found this problem when I drive fast (like on the track). Yes there is a clunch you did not engage properly and it is easy to do. We should learn the old school shifting: From 3rd to 2nd - put neutral, lift left and down 2nd. From 1st to 2nd - directly down without going neutral.

You are glad to hear that it is normal. Second gear is very noisy. Particularly for people who have installed the RP short (sport) shifter (still the right name for it 'Mez?).

Timbo, I think the RP shifter helps with the action but not the noise. Just ask Little John

ILIV48

I had a similiar problem and Mazda was saying there was no problem. One day I was talking to a family friend and I mentioned the problem. He having grown up as a mechanic for Holden then Service manager for toyota said he could fix it if I gave him the keys. He took the car and cained the living **** out of it. Gave it back to me later grinning broadly while saying syncro's adjusted.

He was right after that I never had a problem. He said it was an old fix they use to use all the time when someone would complain of such problems and it worked just about every time.

I'm not saying give your keys to a mechanic to abuse your car but it worked for mine!

xxup

Used to be known as "beating the synchro"... Seems okay to me, but then I don't drive it like I am in a race (not all the time anyway! :o )

Took me a while to get used to driving a manual again, but I do notice that second gear likes the clutch all the way to the floor...

RXXX8

ooo thanks taka. yeh it happens more so when u downshift from 3rd at high speeds... but yeh like i was racing the other night and for once it happened 1st going into 2nd.. wasn't that good!

does it do heaps of damage though to the gearbox

timbo

I recall someone (Gomez?) saying that 2nd and 4th gear share the same shaft, which might be why they are a bit noisier.

This is more so with the RP short shifter, but as I posted in Little John's earlier thread, his solution of loosening the **** (back off, taka!) worked really well for me.

I've also not had a 3-2 gearchange problem, but then I have an old habit of double-declutching that change-down on any car (comes from formative years driving old trucks on farms )

rotarenvy

I use to have problems with the 1-2 change but ether the transmission freed up or I got use to the change.

on a similar note is it bad to change down 4-2 with heal-toe? my last track day the instructor was talking me through the track and said change down 4- 3 -2. as he said it; I'm like WTF I don't have enough time or coordination to do that before the corner

takahashi

no.... I guess it is a matter if your hand is quivk enough.

geisha8

Same here with the 2nd gear issue. Feels like a soft "clunk" when upshifting from 1 - 2 so I gues I should cane the shitoutofit instead of getting someone else to do it eh? :D

skc

I find that the 1 to 2 shift smoothes out once the car has warmed up. But before that there is a definite clunk and resistance to get into gear.

skc

RXP33D

agree with skc.

I find it impossible to crunch gears at the track given that you clutch right,
as the shifts are magnetic for the next gear when warm.
Bump on WPNRX8s questions: Does it do alot of damage crunching those gears?
Perhaps a synchro would dissapear??? OR even all 3?

Hymee

iTrader: (1)

I was thinking about a related thing last night, trying to get to sleep...

Could there be a problem with the clutch dragging???

Once, at the "lights" I was sitting at the red at fairly high RPM with the clutch fully depressed. The car was kreeping forward. I hope the air in the bell housing wasn't acting like the fluid in a torque converter LOL. I wondered if my clutch was dragging a bit.

The other thing I noticed was at one place, on one,of the "special" roads I drive on, I often got a "crunch" changing 3-4 at hight RPM. I wonder if the clutch dragging a bit then would cause that? I thought I had the clutch pedal to the floor.

Cheers,
Hymee.

BVD

Same here. :D

I think that we can sometimes be a little overambitious with what we expect a gearbox to be able to do - i.e. cover up for what can sometimes be fairly harsh or sloppy changing.

For those who've never dismantled a gearbox, what's happening inside a manual box is that you are trying to slide gears together that are spinning at two different speeds. The syncro is like a small metal clutch device that has to rapidly slow down or speed up one of the gears (depending on whether you're changing up or down) so that they can mesh. This is not necessarily a completely instantaneous operation.

Timbo's method, coupled with a sympathetic appreciation of what engine revs are needed to produce a reasonable match up, gives a smoother and less mechanically stressful change.

Gear changing was quite an art in the days of pre-syncro "crash boxes" and drivers who couldn't judge the revs well got a crunch every time. When I was at college a friend had an old Riley Brooklands with a crash box, and he was superb at judging the timing and revs of his changes. He could even do some of the easier up-changes without using the clutch at all, just by easing it out of gear, matching the two speeds, and then sliding them together. A degree of sensitivity that was always way out of my reach! But I guess we weren't in quite such a hurry in those days... :D

The only problem I've noticed with the box on my 8 has, oddly enough, been when changing UP into 4th. It can sometimes be a bit 'stiff'. Usually this seems to be when I'm being a bit heavy handed and trying to shove it into gear rather than using a lighter touch and allowing it to centre itself and slip in nicely. I've just put it down to my being a bit slack and not paying the same attention to changing smoothly as I tend to do on downshifts.

Jellybean

With respect to the caning-the-****-out-of-it technique for curing gearbox problems, I've never found that caning the **** out of any piece of machinery did more than shorten its life expectancy. The gearbox in your car will respond much more happily to proper technique than to any amount of abuse.

However, if you have more money than sense, cane away to your heart's content.

ILIV48

No nor do I. The comment he made to me was in reference to brand new (just purchased) cars and not just any car with gearbox issues. My car had off and on grinding in the 1 to 2 and the 2 to 3 changes (going up the gears). After his spirited use for a few minutes my gearbox has not made the same noise since nor has it been abused since either.

He was talking about the syncros not being bed in properly from the factory or something along those lines. I can't remember exactly what he said now. It was a fair while back now!

Jellybean

Thanks for that response. I guess it's not very reasonable to disagree with experts when they have reasons for doing what they're doing, but it still seems to me that components in a new machine will usually bed-in satisfactorily if you are patient with them and use standard running-in procedures.

Still ...if something works for you, who can argue?

ILIV48

Yeah he says that with manufacturing techniques there are always variences some for good others for bad although the car companies will never admit that. Because of these variations sometimes parts may need a little helping hand!

But you do have to know what you are doing.

labrat

How old is this guy? He might have been talking about Holdens through to the 80's, but the Japanese pioneered the use of TQM in manufacturing processes. Variations are typically very low and are measured and strictly controlled. Compare this to the old days at GMH where various piston sizes were made to fit the imprecisely bored cylinder holes in engine blocks. It has been the Japanese who are responsible for the high quality of modern cars and why they represent the benchmark. Be very careful about believing anything this mechanic tells you.

RXP33D

I believe this is called KAIZEN.
Zero defect...

sco

I can't say I've ever had much trouble with crunching during shifts. I've had one crunch from 1 to 2 under high revs and I'd say that was me not concentrating and forcing the stick a little early. Only hassle I've had has been the odd refusal to go from 2 to 1 at a slow speed which a little ride of the clutch in second gear fixes.

Nothing is better than getting the rev match spot on and the stick slides effortlessly into gear... always brings a smile to my face... but can't say I've mastered it yet.

Was bloody paranoid the time I drove Hymee's car with the short shifter, but thankfully didn't manage to hurt his car, but drove pretty badly because of it (paranoia that is, not the shifter).

All this talk of spirited driving... must be time to organise a bit of a spirited drive.

xxup

Yes please... I'm also keen to see your screen setup...

ILIV48

He has just retired from running a dealership and another of my friends owns a Honda dealership. I currently am working with Mazda, Mitsubishi and Mercedes on various projects. I have been getting a lot of behind the scene's talk from all these guys and believe me this zero defect thing no chance. All of them are having quality problems. Toyota has just been adjusting all the clutches in one brand of car as they have come from the factory wrong. The owners are complaining of excessive gear crunching and refusal to go into gears. Mercedes is having problems with rattly interiors as the fitment in the cars from factory is less than perfect.

Why does the rx8 seem to have fuel economy figures dependant on which car you drive. Why do same day dyno's of the same model new cars on the same dyno vary so much. My last car dynoed 107kw at the wheels, my closest friend with exactly the same car with almost identical Km (approx 11,000km as we bought at the same time) then put his straight on and got 94kw. In a straighline my car would pull away from his in every gear.

Having been designing products for manufactur now for 10 years some of which has been car parts/accessories everything has a small tolerance of error allowed by the munfacturer. The parts then go into the storage rooms/area's/part bins to be pulled out later for use in the putting together of the end product. If 2 parts to be used together are slightly out (but still within the mabufactuerers specified tolerances) but they are both say on the very outer of both on the very inner scale of the tolerance then this is where an issue can occur. In the past this happened more often than it doe's now. But it still does happen.

Here at work one of our businesses is manufacturing toys. All designed on computer and manufactured via computer automated processes to give miniumum variations and out of every 1000 toys we see 5-15 that just do not work as they are supposed to. When found these items are reverse engineered to find out why. 25% of the time it's due to a material fault and so far approx 75% of the time it is concluded that when all the variances of the individual pieces are added the total variance of the product exceeds the that which enables it to function as specified.

Besides why do some of the Melbourne guys have RX8's with rattle free interiors while others like me cannot listen to the cd because of the noise/rattles their inteior makes. I have rattles in the center piece running through the car, both doors, behind the cd player, behind the instrment cluster, in the back parcel shelf, have had the cd player replaced twice, had the rear brake calliper seize and replaced, driver seat replaced and air conditioner replaced because of faulty bearings I think it was. I do not abuse my car and more often and not treat it with kid gloves. Only went on the track once and all these issues existed before then.

So when it comes to zero defects/tolerances I just cannot see this being truthfully claimed by anyone. Manufacturing is improving but it's not perfect.

Cheers

PS. Sorry for the long post!

BVD

I agree - it's impossible in practice to smooth out all variances in manufacturing.

My original background is in motor engineering, but for a while I had a shop selling CDs and exactly the same issue occasionally occurred there too. If the tolerance on a customer's CD player went in one direction, and that on the CD itself went in the other direction, they sometimes would not play at all.

Yet when they brought the CD back it would play perfectly on the player in the shop. Replacing the CD would not necessarily fix the problem as the tolerance variation was just as likely to be similar on items from the same batch.

As with most things in life, there's no 100% certainty - just better percentage odds with some products than others.

Hymee

iTrader: (1)

If the widget tolerance is 80mm +/- 10mm...

Then if every widget was between 70mm and 90mm, then that would be zero defect.

An extreme example, but you get the point.

Cheers,
Hymee.