Vindicator

So I had my 2005 TSX 6MT in this morning for very basic service - oil change, check brakes etc.

Not due for tranny fluid or anything else relating to shifting.

On my way from the dealer to work, the thing makes a nasty grinding noise (like the synchros aren't meshing?) any time I shift into 3rd. Noise comes immediately upon putting the shifter in position, while clutch pedal is still all the way in, so it seems it would be a synchro problem and not a clutch or gear problem. All other gears are fine. 3rd makes the noise on upshifts and downshifts. If I'm stopped at a light (engine running), I can move through all the gears (leaving the clutch pedal in the whole time), including 3rd, without the noise.

Never made a peep before, from the day I took delivery up through and including the drive to the dealer this morning.

I'm stopping by to drop it off and pick up my loaner on the way home. Any guesses or theories?

curls

Should be in the Problems section, but that is really bizarre. I don't see how an oil change could have caused this.

(Unless they had a tech who drained the tranny but filled the crankcase, LOL)

Vindicator

I had the same thought, but that should affect all gears, not just 3rd.

I should also add that after the initial noise, the shifter slips into place just fine, and there's no problem with letting the clutch pedal out and driving in third.

I could only think that they must have bumped/hit something and knocked it out of whack, but they shouldn't have been near (or had open) any of the suspects that would come to mind based on my limited knowledge of what the car looks like from below.

Oh, and sorry if this should have been posted elsewhere - my bad.

I'll be interested in any and all theories and if the dealer gives me any answer, I'll post it.

Vindicator

OK, finally have a report. Not surprisingly, dealer says it's totally unrelated to the oil change/service they did.

They replaced the entire third gear assembly, including the gear and the synchro.

Service advisor told me that the third gear synchro is an "updated part," so even though there is no Service Bulletin "yet," they must have had some problems with this.

He also said that shifting directly from, say, second into fourth, can cause problems and that there's an Acura bulletin on this which he'll give me tomorrow when I pick up the car. I must admit, I've done this a time or three, but it's rare.

Anyone else here ever have a third gear synchro problem? Anyone think this sounds like a CYA story?

curls

I think its a CYA story as you suspect.

But if their remedy solves the problem, great!

Vindicator

I now have the handout they gave me, from the January 2006 Acura Service News. It says that "skip shifting" (ie, shifting from 2nd directly into 4th) is "brutal" on synchros and will cause premature wear. The reason given is that a skip shift requires a larger change to the speed of the mainshaft and the clutch disc than the synchros are designed to handle. Shifting through gears in order only requires small changes.

Interesting. Given that I rarely did this (and when I did, it would be using 4th to accelerate all the way up to cruising speed on the highway and then shifting straight into 6th) I can't imagine it caused my problem with the 3rd gear synchro. Even more so if the dealer was telling me the truth when he said the new part was "upated" compared to the original part (which seems to indicate a design problem with the original).

But still, it's not something I would have known, so I'm passing it along. Happy shifting!