mrmarbles

Hello

Was wondering if anyone could help with a problem I've been having with my 04 TSX 6MT. It's got 120,000kms = ~80,000m.

Sometime last fall, while putting the cars through its paces on the backroads, I noticed that it was taking a split second long than normal to change gears, say from 2nd to 3rd, at high RPM. Not very noticeable, but the odd time it was just long enough that it would mess up my timing and I would blow the shift. At the time, I thought it was all in my head.

Lately, I've become convinced that there is a real issue. The shift action is noticeably worse than before. It's noticeable in all gears. Of particular note:

- I've heard the gears crunch on three occasions when shift into reverse (to park). I've worked around this issue by double-clutching
- Getting into first (at a stop light) is more difficult than it should be. It seems to take a little more force than I would like to use. I usually try, and if it doesn't go in nicely, re-center the shifter, and then next time I try it goes in better.
- Shifting from first to second is okay at low RPM. When the RPM is higher, I definitely have to wait and shift a lot slower than I used to.
- When shifting from 3rd to 4th, sometimes it seems like third want to throw the shifter out of third, if you know what I mean.
- The shifter doesn't want to go into 6th gear unless it's at the perfect RPM. I haven't forced the issue.

It's still very driveable day to day. I'm not sure that someone else would notice (well, except for the crunching going into reverse).

Anyway, if you've made it this far, I'm just looking for recommendations of where to start to look. Clutch, synchros, ? Any recommendations/advice/stories would be greatly appreciated.

Thanks,
Jeff

huludicidal

As far as the issue of getting it into 1st or reverse from a stop: the output shaft/clutch splines are no longer lubricated (Honda Urea grease) as well as they once were (on day 1). The results are:
a) sometimes it is hard to put it in first or it won't go in at all unless you put it in second then go to first,
b) sometimes putting it in reverse grinds a bit

I am about 99% sure I've seen a TSB about this but it's not really an issue. You can get a new clutch or just rip it apart to grease the splines but it's not that big of an issue. As far as the other issues, it sounds exactly like the synchros have seen better days. Probably time for a rebuild. Since you have only 80K miles on the car, regular (gentle) driving conditions won't be hard on the synchros but sporty driving with fast shifts (up and down) cause premature wear. I'm assuming you shift fast often and it's time to have the tranny torn down.

mrmarbles

Thanks for the reply.

I wouldn't think that I've been that hard on the car. Yes, I probably did shift faster than some. But one of the joys of the car has always been running through the gears.

Any ideas of what to budget for such a job?

Simba91102

Could be synchros, but sounds more like the clutch to me. Either way, if you're going to have the car apart, just plan on doing both jobs. A new clutch will magnify the lousy shift quality of worn synchros and vise versa.

mrmarbles

Here is my quandry:

I was thinking of getting out of this car fairly soon anyway. I would rather not put - what - 1500 - 2500 (more?) into replacing the clutch and rebuilding the tranny of a car that I was hoping to get out of inside of a year.

I guess I'm wondering - is this a time bomb that could explode soon, or more of a slow degradation? Is there anything that can be done to prolong the existing tranny/clutch? I replaced the transmission fluid a few days ago. It's been a while since I've replaced the clutch fluid, but the level is good.

Thanks again for the replies.

huludicidal

^^ It's so hard to tell with transmissions. When I've had clutches go, it was always a long ordeal; it would start slipping then the car would just stop moving in higher gears. When I've seen synchros go, it was always someone racing or doing prolonged burnouts and they went instantly. I do know that premature synchro wear usually shows up as the inability to shift smoothly, most commonly, between 2-3 and usually is very apparent when downshifting.

Did you use Acura/Honda MTF when you changed the fluid?

If you're planning on getting rid of the car, think about it as an investment. A car that needs a new transmission has a resale value that is usually far lower than the cost of the new transmission + labor. If your car is in good condition and you expect a high resale value, I'd spend the $2K and get the tranny work done, then sell it. A buyer won't see your car and get red-flagged but will see it as a well-maintained good purchase.

mrmarbles

Interesting comment. I've noticed no slipping whatsoever. I haven't noticed any change in the grab point either. Never done any racing/tracking/autoX etc. with this car. Never done any burnouts. However, the car was 2nd hand, and I've only been the owner since 55k = ~35k miles.

I don't notice any hesitation going in or out of gear when downshifting. I can be coming off the highway at 70mph and downshift into 4th or 3rd without any issues (blipping the throttle, putting it in gear).

I used honda MTF when I had the transmission fluid changed.

The fifth (or fouth) to sixth shift is what has changed the most in the past month or two - it just doesn't want me in to 6th until the RPMs drop. That and the lack of smoothness when getting into 1st at a light/stop sign.

Driving around town today, in a casual manner - I didn't really notice any issues -- perhaps why I didn't notice many problems in the winter time, when i'm less likely to wind it up.

Anyway - not sure if that clarifies anything, or just muddies the picture.

huludicidal

I have 85K miles on my TSX and don't have any of the issues you described except occasional reverse grind and after it sits overnight, it is harder to find first. Those issues are associated with the grease (or lack of) on the clutch shaft splines. Your issues are really hard to diagnose without actually driving the car. Maybe have the dealer drive it, and wind it up, and see what they think.

The sixth gear is what bothers me. I read a TSB about premature synchro wear associated with 4-6 shifts. Acura claims, and I'm not sure how much truth there is in this, that 4-6 (skipping 5th) shifts cause premature wear on the 6th gear synchro since it is designed to match 5-6 shifts optimally. I feel like there are many drivers that love to wind up the K24 to the speed limit then just drop it in 6th and cruise, usually translating into many 4-6 shifts. If you do this often, Acura will blame your driving style and recommend the synchros are replaced. I kid you not, the TSB instructs the service person to ride along with the customer and to watch the customer skip gears.

mrmarbles

6th gear is definitely a more recent development.

One other thing of potential note:

If I shut the car off, and push the clutch in, and start shifting gears it's very difficult to get into and out of 1st and 2nd. It's even tougher to get into 5th and 6th.

What does this mean? When the car is off, and I'm shifting gears, what's actually happening?

Cheers,
Jeff

huludicidal

^^ So, the clutch is the part that allows the engine to engage the manual gearbox (which in turn drives the wheels). The only difference between your car shut off and your car running with the clutch pressed in is that the flywheel and pressure plate are not spinning and the transmission mainshaft (and clutch disk) are held still.

When you're running through the gears on a stopped gearbox, often times the gear teeth don't match up properly and since the synchros aren't spinning, they can't do their job to match the teeth up. Also, as you run through the gears, you perturb the mainshaft slightly so that other gears may not align properly (with clutch pressed in). This is why on some cars when you're trying to find 1st or reverse and it won't engage, you put it in second then 1st or reverse slides right in. Also, you'll notice that if you're shifting through the gears with the car off and the clutch pressed in, it may be easier to find the gears (engage and disengage) than if the clutch is out. For the same reason noted above, with the clutch engaged, the stopped engine is engaged to the stopped gearbox, thus there is no spinning or movement in the mainshaft. Therefore, when gears are engaged, they may be stressed and you will find it hard to pull it out of gear or it simply won't align with other gears and you'll find it hard put it in gear.

What you're experiencing here has little to nothing to do with failing parts. You typically need the parts in motion, being put under their normal stresses, to determine if something is failing.

mrmarbles

Thanks again huludicidal. Seems like everything is pointing towards getting an expert to diagnose on a roadtest. I've set this up next week with my mechanic. I guess I'll be looking to determine how rapidly a fix is required.

One interesting thing I noticed on the past few commutes -- if I really concentrate on pressing the clutch pedal down quickly and firmly, the problem seems to (almost) go away. If I'm really quick and hard on the pedal, I can even get into 6th relatively easily. Not sure if this indicates anything.

Regardless, I'll document everything, and then let the mechanic take a look. Thanks for the help - I'll keep on checking back in case anyone has anything they'd like to add. Otherwise I'll post back next week.

mrmarbles

Just to provide some closure -- a new clutch kit solved the problem.

huludicidal

Good to hear that it wasn't something more costly like synchros. I guess the worn clutch wasn't fully disengaging, likely due to a worn pressure plate or dry clutch splines, making it harder to put it in gear etc. This is consistent with your other post saying if you pressed the clutch really fast, you didn't have the problem. Did you get Acura do to the repair? If not, did the clutch splines get properly greased with Honda High-Temp Urea?

myRice

Just a note for anyone else who may be experiencing this problem, GM makes a product called Synchromesh. It's probably some of the best transmission fluid out there and it really helps to clean up shifts and somewhat smooth out synchro issues. I've owned many older cars with bad synchros and this stuff is really good.

You can get it at many GM dealers. Just pick it up and replace your current tranny fluid with it.

newfie939

I have the same problem with my car with the grinding in reverse and not going into first at a stop. I was assured by my service dept that a tranny fluid change would do the trick. It did, but only for the first 10k. Now its back to being stubborn again. I tend to do more 3 to 5 around town then 4 to 6, but I guess it could still be messing up the synchros!?!? Time to adjust the driving style me thinks

huludicidal

This is really common on TSXs. Acura issued an official statement about this and it relates to lack of grease on the clutch splines. Depending on how many miles you have, and how much it annoys you, I'd say it's time for a new clutch.

nj2pa2nc

Must be one of the lucky ones=no problems (knock-on-wood) .Recently had the manual transmission fluid changed by a acura dealer. Almost 105K miles.