warsaw

I've heard/read about a problem where if you accidentally shift from 2nd to 5th gear, you get a syncronization problem and a horrible "grinding" sound every time you shift into 5th gear, regardless of whether you're doing it right or wrong afterwards.

I've actually heard it in an RX7 I test drove a few weeks ago.. the dealer said that it happened b/c the previous owner made the shifting mistake.

I'm new to stick shifting, and my parents are freaked that I'm going to screw up going from 2nd to 5th and cost them $200 every time...

What's the deal here?

R.Cade

Not true. My fith gear syncro started grinding at about 95k miles, and I had never miss-shifted.

I was crusing on the highway in 5th, downshifted to 4th for a long exit ramp onto another highway, and when I went back into 5th it mildly grinded into 5th for the first time ever.

The syncro parts where upgraded at some point, so if you get it repaired with the newer parts, it shouldn't do it again. I think i saw the parts and some info on mazdatrix website one time.

Mr. Mahtab

It has happened to me three times in 20,000 miles. Do you think my synchros have suffered bad or can it happen a few times without any real harm? most of the time I dont have a problem, it only happened when I forgot to speed match, ex. cruising on the highway shifting to neutral than throwing it in to fifth (GRRRRaaank!)

What you think?

misdbman

Once the trans is upgraded with the superceded parts, it should not break again that easily. It will cost a lot more than $200 though. You can't get most people to pull the trans from the car for that much. Mazda will want double that just to pull the trans not counting fixing it.

artguy

ok..here is the deal.

I had a syncro prob before 64k and the dealer fixed the problem.

they put in the correct parts...the upgrade

I missed a shift from 2-3 and hit fifth twice in the past two weeks while racing another rx and a supercharged vette... I fried fifth and reverse in totality.

IF you are missing shifts...pull off the shifter and the center console area (10 mins max) and check the bushing on the end of the shifter...it looks like a little plastic cap for a water bottle...it fits on the end of the shifter that dips down into the tranny...if it is torn...replace it for four bucks..that four buck part cost me a shitload of time and my missed shift cost me 425.00 ( a sweet deal through my neighbors shop) .... all in all it was about a 1500-1700 dollar job...which I got a total deal on.

basically....a bad missed shift WILL CAUSE FAILURE IN PARTS OF YOUR TRANNY. in my case it was the synchros on fifth and reverse as well as the entire fifth/reverse section of the transmission. 300 in parts...a day to get the thing out myself...125 labor (friggen lucky) on the the tranny...and a long evening putting it all back together.


best of luck...DONT miss. it has happened to me twice...

Im ordering the short shift kit...it aint happening again.

jason
94 PEG

MrFreeze

hey im pretty much a newbie too whats the short shift kit doo btw? =)

alexm

Guys, you're reading his post wrong. He's saying:

"I was told if I shift from second to fifth (not grind, just skip 3-4) I will need to have a $200 repair."

Whoever told you that is a yutz. Here's the REAL deal.

The RX-7 is sensitive to grinding. When shifting from SECOND to THIRD, you can grind THIRD/FIFTH if you do it wrong. In other words, if you have the shifter too far to the right for third, and too far to the left for fifth, it will try to engage both, and it will grind. If you do this a few times, you will wear out the syncros, and it will grind just shifting into fifth normally.

HOWEVER, if you just shift from second to fifth, nothing bad will happen. Also, do not get a short shifter, as this will make it even easier to mis-shift. The RX-7 shifter feel is pretty good stock.

Remember: When driving aggressively, and you want to shift from 2 to 3, just push the stick up, and it won't grind. It's those who try to push the stick over too that end up catching 3rd AND 5th and grind.

And that whole $200 repair is BS. When your syncros go, its $1000+. Don't ever ever buy an RX-7 which grinds going into 5th unless you are getting an incredible deal, because you'll be spending $1000 real quick.

warsaw

thanks for the tips guys... and alexm, I'm buying an RX7 *without* any grinding/shifting problems. The deal is, the dealer told me that if you mis-shift from 2nd gear to 5th gear by accident, the grinding will begin to occur -- quickly.

My parents are just worried that for every time I make the mistake of going from 2nd to 5th, I'll end up with the grinding problem..

See, a couple weeks before now we test drove an RX7 that would grind going into 5th gear REGARDLESS of what gear you were shifting from -- my dad realized this when normally shifting from 4th to 5th.

All I'm wanting to know is, how many times will I need to go from 2nd to 5th by accident for 5th gear to start grinding and the need for a repair to the transmission/clutch to arise?

maxcooper

If you drive carefully for a while and learn where 3rd gear is, you will not be likely to jam it into fifth when you meant to put it into third. As someone else mentioned, do not push to the side and you won't miss third -- it is straight forward.

My fifth gear synchro went bad because I let other people drive the car and they pretty much always miss that shift, because it takes some getting used to. You do not need to get a complete tranny rebuild, so it should be $500-$800 including parts.

My car had 71K miles and no doubt some missed shifts on it when I got it. I missed the shift several (5+) times when I first got the car. Other people driving the car after I got it probably missed the shift 10 times. It doesn't take a lot of missed shifts, but I don't think it is likely to happen if you miss it a few times.

The FD has a great transmission. I like the way it feels, and it is way more durable than a DSM, Subaru, etc. I have 103K miles on the car now, and with the exception of having the 5th and R gear synchros replaced, it had held up fine. You don't get into real problems with power until you are way up there at 450+ RWHP. We don't have much to complain about.

-Max

alexm

Yes, that's correct. When the 5th gear syncro gets worn, it will grind when shifting into 5th no matter what gear you're coming out of (4th, 3rd, etc). It simply can't engage cleanly and grinds. So the best way to test for 5th gear syncro wear is to quickly shift from 4th to 5th, if you hear any grinding, stay away, or knock $1000 off the price.

I want to make sure you understand what I was trying to say. If you just shift from 2nd to 5th, NOTHING bad will happen to your car. You can even shift from 1st to 5th if you really want However, if you shift from 2nd to 5th and GRIND 3rd and 5th together, then it will wear out your 3rd/5th gear syncros.

So again: Accidentally shifting from 2-5 because you put the stick too far to the right = harmless. Accidentally shifting from 2nd and grinding because you put it just far enough to where it won't engage into third, but can't quite catch 5th = bad. You can probably do it a dozen times or so before it gets relly bad.

Most people mis-shift when they are racing the car, or driving aggressively. Because they try to shift more quickly, if they don't have the pattern down, it grinds. The thing is, when you're shifting quickly you slam 3rd and 5th together that much harder - which is why it wears so quickly. If you're just driving normally, (A) you will almost never mis-shift and (B) when you do, it won't be as bad as when you're being a stoplight hero.

Alex.

ATPRX7

When your 5th gear synchro is gone, when you are in 5th and try to downshift into 4th it will grind too right?

warsaw

OK alex, all sounds good

So basically, all I need to look out for is making CLEAN shifts into 3rd and 5th, each one leaving the shifter straight up the middle of the respective gears?

alexm

Yes, basically. The shifter will always be in the same spot when it's in gear, but basically, when people shift from second to third, they generally move the shifter a bit to the right, and push up. With the RX-7 (and other cars like the eclipse) the proper way to shift to third is just push up. For fifth, you generally have to push a wee bit to the right from fourth, but it's still the same general upwards motion. That's all, just don't try to pull the stick to the rigth when shifting 2-3 and you won't grind 3rd and 5th together.

But you're right, clean is what I was trying to say Shift cleanly and it won't be a problem if you pick the wrong gear accidentally.

Alex.

1FAST7

hey, i had a question as well. If u get a short shifter kit will this problem ever happen again? whats the deal with the short shifter kit?

1FAST7

alexm

A short shifter makes the throws between gears shorter. In other words, let's say the throw is 4" between first and second, a 25% short shifter would make that 3". Mike3ymomo had a short shifter in his car, and I didn't particularly care for it. He did it to fix the grinding problem, and he said it got worse, not better. To me the feel felt all wrong as well - the stock shifter on the RX7 is really good, and to shorten it makes it feel weird, not better.

Just my opinion though, some people like em. To me it seems like $300 to make the shifter feel worse.

Alex.

Donovan

This is the part that causes the grinding. It is a broken 5th gear synchromesh gear. You can smash it by miss shifting 2 to 3.

Donovan

By the way anybody know about a 6speed for the FD?

Ryan95

iTrader: (10)

The dealer is half right.
I missed one shift and broke the syncro in my car which had 33K on it at the time.
And it's more like a $900 repair.
Tell your parents to buy you a car better suited for a kid.

maxcooper

I intend no disrespect or flamage, but I am not necessarily on board with the "5th and 3rd at the same time" theory. I think the event that kills the synchro is jamming the car into fifth with the revs way up and not moving all that fast (<75 MPH). The synchro does not have time to slow the clutch disc down to the RPM that matches the vehicle speed, so it tears the synchro up.

But I AM totally on board with the idea that this happens when you are driving hard and push the shifter too far to the right, grabbing 5th instead of third. Just move the shifter straight forward to go into third. You need to push it over a bit to get it into 5th. They are not both straight forward. For third, just push it forward -- it will be guided into the right gear for you. For fifth, push it away from you a bit to get it into gear. Do it slowly at first and then do it progressively faster to avoid making mistakes. Train yourself to do it right.

May there be no misunderstanding here -- the 5th gear synchro is in effect only as you engage 5th gear. It may help avoid grinding if you pull it out of fifth slowly, but the purpose of the synchro is to match the revs of the moving vehicle and the clutch disc when you engage a gear -- not for any other reason. If your fourth gear syncho is fine, you won't have any trouble getting it into fourth.

The sequence of gears you choose does not matter at all if you match the revs by letting them naturally fall for a moment on upshifts, or blip the throttle when downshifting. Don't worry about how to blip the throttle -- just focus on understanding what is happening with the tranny for now. After you drive the car for a bit, you don't have to think about what you are doing -- it becomes natural. But it does help to understand what is going on when you start trying to drive a car with a manual transmission (the basic principles are the same for any street car). Knowing what is going on helps you improve your skills by avoiding bad habits and reinforcing good ones as you modify your usage to make it all go more smoothly. The best drivers cooperate with the car rather than fight with it -- good driving is more like dancing than wrestling.

Okay, here's the short simple version:

- People often push the shifter too far away from them when shifting quickly into third gear, and end up in fifth by accident. Since this usually happens when driving fast, it is only natural that it happens after second gear. Avoid doing this.
- This mistake kills the synchro for fifth gear after several occurances, which means that the tranny will grind when you shift into 5th gear. Once you kill the synchro, it will grind on nearly ALL shifts into 5th until you get the synchro replaced, even slow shifts.
- You can have the 5th gear synchro replaced for $400-$900. This is much cheaper than a full rebuild, but it is expensive enough that you won't want to do it again.
- Don't read anything else about gear sequences into this. It will grind only when entering 5th gear, and it is simply circumstantial that it usually happens after coming out of second gear.

I hear that GReddy (or RE?) sells a 6 speed for the FD in Japan, but I don't know anyone in the U.S. that has had one installed. There was some talk about putting the Miata 6-speed in the car, but I don't know what came of it. There will be a few V8 6-speed RX-7s running around before too long if they aren't already, but I don't think that is what you meant.

-Max

fluxen

Another tip to avoid mis-shifting into 5th:

If, when in gear, your shifter moves a little side to side, try taking off the center console cover and tightening the 3 bolts that sit beneath the rubber boot (surrounding the shifter). These 3 bolts provide tension to hold the shifter in, and if they're a little loose, your shifter will be very sloppy. Tightening them a little will make the shifter absolutely solid when in gear, and make missing 3rd much less likely. BTW - I'm not talking about torqueing the hell out of them either. Just a little tightening, like perhaps 10lbs. I do it by feel, and if you make them too tight, you'll barely be able to move the shifter to get the damn thing into gear at all, so you'll want to lessen the torque a little. Just do it to feel. If your shifter still moves around in gear after applying some torque, replace with a short shift kit to solve the problem. I've got the Mazdatrix short shifter, and it's pretty good, but I have to retighten these bolts every several hundred miles (but it's probably got to do with all the track time my car sees).

Also, regarding the plastic bushing on the bottom of the shifter, it's not supposed to matter. Mazdatrix has tested with and without it, and it apparently makes no difference whether it's there.

fluxen

On the nylon bushing, I gave some wrong information I wanted to clear up. Mazdatrix said the nylong bushing made no difference in some noise the short-shift kit can make on certain FD's. They did *NOT* say it made no difference to the tranny. Mazda itself says running without the bushing will wear the synchros prematurely, and they even sell a aluminium bushing for racing purposes. Sorry about that...

toppdogg_1

What is speed matching, the same thing as double clutching

Mr. Mahtab

Just getting the rev's back up to the same (or near the same) as when you shifted out of a gear. In other words what I did, while cruising down the highway, I noticed that my car was overheating, so naturally I freaked out and threw my car into neutral. Then I turned my heat on high and watched the engine temp drop back down, thinking I was okay, I tried to put it back into 5th gear basically coasting at 50mph and at 800 RPM my engine speed wasn't up there and I felt and heard a GRRRRAK! It wouldn't even go into gear. it was a Bad sound. But, my 5th gear still works so I don't think I killed it.......cross my fingers......

TriangleMan

sort of...
you know when you shift how your rpms go down in the next gear? say you are doing 3000 in second and shift to third which brings it down to a nice even 2000. if you slam it in third then the tranny will have to make up for the difference in the gears spinning.

while your tires are moving, each gear in the tranny is spinning at a different speed. the higher gear ratios (like 1st) are spinning much faster than the low ones (like 5th). the gear that is connected with the engine is spinning at a certain speed associated with your rpms when the engine and tranny are disengaged (your clutch pedal is pressed in or you are in neutral in the shifter), and your 2nd gear is linked to it at the moment, which is also spinning that fast. the other gears are smaller and bigger, and say 3rd gear is a little bigger (bigger gear = lower gear ratio = higher gear number, you know, 1st 2nd etc.)

so if you shift and your engine rpms stay at 3000, the gear connected to your engine is spinning faster than the 3rd gear, which means the synchros have to match the speeds of the two by either

a. slowing down your engine speed, happens when normal driving

b. speeding up your transmission gear and hence your tire speed, happens when you race and catch second for instance. your engine delivers so much power that the synchros make the tires spin faster and chirping them

so if you let your revs drop so that as you put it in 3rd you are at exactly 2000 rpm, your gears will be doing the same speed, thereby avoiding wear and tear on your synchros.

the same goes for upshifting, if i'm at 2000 rpms in 3rd and want to shift to 2nd, i could just put it in gear and let the synchros do the work, but if i blip the throttle (tap the gas as i'm shifting and time it so that when i put it in 2nd gear i'm at 3000 rpms) then the synchros are again saved the trouble and they can live to see another day. if you really want to have fun, instead of blipping the throttle, just floor the gas. i'll be doing 4000 rpms in 3rd at about 45, floor the gas, drop it in second with the gas still floored. the tach looks pretty cool when i do that

go to http://www.howstuffworks.com/transmissions.html and that has some good stuff, that's how i learned about them.
that was supposed to be matching revs and turned into what your tranny does as you shift...o well, no worries. hope it wasn't too confusing

double clutching is used for the same purpose, to reduce wear on synchros, but i think it is more used in vehicles with NO synchros, such as semis that have like 10 forward gears. that is when you are in 2nd, put in the clutch, take it out of second, release clutch with gear in neutral, push in clutch, put shifter in 3rd, release clutch. if you do it in your car you can feel how easy it is to shift. i don't know how that works as far as the synchros but i know it does

WHO

Well, obviously I got tired aftr the 6th or 7th post, so don't flame me if I repaet something that's been said.

I let my bro drive my car at a drag racing event - that was my first mistake, don't EVER let someone else drive your sweet sweet car- and he fu(ked up my 5th and reverse real bad, I'm gessing he missed his shift from 2nd to third...

Now, it cost me below 1k CANADIAN to fix that problem and also a coiple of other problems, including labor and all, I figure the cost for labor and parts for the tranny was no more than 700$ CAN.

So if you pay more then 500$ USD for that fix you got screwed... cause I had the fix done by the ex-director of Mazda Canada's technical services, so you can guess he is NOT the less expensive guy around, but knows what the deal is with those cars.
Cause the second mistake I did, only once, was to bring my car to a Mazduh dealer, that was for ythe pre-buy inspection.

The very next day that I bought it, the exhaust fell off, and I discovered boost problems soon after, so they were all wrong when they told me it was A1 quality.