Great To Be Alive

Hey Guys,

Hoping to get some help regarding diagnosing a drivetrain issue I'm having with my '08 S. I've always had the rough / grinding shifting issue from 1st to 2nd when cold, since day one of owning the car. Replacing with new Honda MTF did nothing to help. Once the car warms up though, it seems to shift reasonably well.

Last time I had the car out, though, I was turning right to merge onto a city street... and after down shifting to 2nd and begining to release the clutch coming out of the turn, I heard a horrible ratcheting noise and didn't feel any drive to the rear wheels. I immediately engaged the clutch again and the noise stopped. I then released the clutch (still in 2nd, never moved the shift lever during this time) and no noise. It happened very quickly, so I sort of did a double take... Did I really just hear that? The rest of the 15 minute drive home I couldn't duplicate the issue, but now I'm a little worried to even drive the car. I talked to the local dealer today, and while they were very nice, they did say they would have to duplicate the problem. Hoping you can help me focus on the key indicators of tranny Vs. differential.

I guess the simplest answer would be that the gearbox just missed engaging 2nd, and then found it on it's own when I clutched again. But now I'm starting to wonder if it may have been differential. I've always had this wheel spinning sensation when making right hand turns from a stop sign onto another street. For the longest time I thought I was just slighly spinning a wheel on the painted white crosswalk lines... but it happens too consistently for that. Is that feeling of the wheel losing traction slightly typical of a LSD? Since we don't have a clutch in our LSD, I'm wondering if this might be a symptom of a faulty hypoid gear or missing tooth.

The dealer offered to drive the vehicle with me, but hoping to get some feedback first on the above so I can help the dealer focus on the most probably cause. Don't want to send them on a wild goose chase.

BTW: I have less than 5K on the car now, and just changed oil/filter, and tranny and diff fluids. Honda MTF for the tranny and Amsoil Severe Gear 75w-110 for the differential based on all I have read on this forum.

Thanks in advance for the replies.

Robert O

Do you get the same wheel spin symptom whether the VSA is on or off? Otherwise I recommend replacing the clutch fluid.Suck out the old from reservoir with a suction bulb.Refill with clean. crack open bleeder at slave cylinder and bleed until the reservoir level drops to about 1/2 " from bottom.Close bleeder and refill reservoir.Repeat procedure a couple of times until clean fluid weaps from bleeder. If you can't clearly see the bottom of the clutch fluid reservoir,the fluid is dirty. This helps eleiminate the grinding into gear symptom you mentioned.Delay shifting a bit helps as well. It takes practice.

Great To Be Alive

You know... I've never had the VSA off. Assuming you mean do I get the same slight wheel spin sensation on right turns froma stop with the VSA off? I'll have to try that tomorrow and see.

Robert O

[QUOTE=Great To Be Alive,Jan 3 2011, 06:27 PM] You know... I've never had the VSA off.

flyingtoaster

This has happened to me in my S2000 several times, as well as in my Acura Integra. It was always because I had the shifter halfway in second gear. You can duplicate it by holding the shifter halfway in gear but I would not recommend it. Just be assured that you did nothing to hurt the transmission and it probably won't happen again.

To improve shift feel, switch to GM Synchromesh Friction Modified. Keep in mind that 98% of Honda manual transmissions under warranty come with a FWD transaxle, built by Honda, with an integrated differential. The remaining 2% are the few S2000s like yours that are still under warranty and have a RWD transmission that was built by Aisin. Do you think that Honda MTF was formulated with us in mind?

SpitfireS

Great To Be Alive Posted on Jan 4 2011, 03:10 AM
5K milles.. that's not a lot, IMO the gearbox is still breaking-in.
Drive more & shift more
Both wheels have traction but the outside wheel spins a lot faster (as if its slipping but it's NOT) so the Torsen starts to lock but it cant '(really) because you're in a corner and the wheels should spin at different speeds.
If the inner wheel unloads a bit it will try to spin a faster, "driven" by the outer wheel, that's how the Torsen works.
The Torsen doesn't know the difference between driving straight with one wheel spinning faster (loosing traction) and taking tight corners with one wheel spinning faster (normal traction).
The 75W-110 is a very good choice

flyingtoaster Posted on Jan 4 2011, 06:52 AM
Wouldn't you say that a buid-in diff makes it harder for gear oil?
IOW, if OEM MTF-II is formulated to deal with transmissions & build-in diffs it should handle a single transmission just as fine, no?

That said: I would not use any other than Amsoil MTF, after trying OEM, GMFSM and Amsoil.

Great To Be Alive

Thanks guys... now I feel a bit better. Based on both your feedback, it sounds like the sound was probably transmission related, and perhaps I just didn't have it all the way in 2nd gear. Especially given Spitfire's description of what the Torsen LSD is trying to do, the differential may be just fine. Do all S2000's have the slight slip and catch feeling in tight turns then? I'm also thinking that if the differential was going out, it wouldn't be intermittant... but would just let go all together.

Now that I'm not as concerned the car will leave me stranded... I'll take it out tomorrow and see if anything strange happens. Hopefully all will be well, but I'll let you know what I find. Thanks again.

ronnuke

Yes it sounds as if you just had a lazy shift into 2nd and didn't quite make it all the way into gear and grind the synchro ring. No harm done. Check you clutch fluid for level and cleanliness as mentioned.
I too recommend the Amsoil MTF as well as Amsoil full synthetic engine oil and Amsoil Severe Gear 75W-110 for the diff. I guess I am just an Amsoil fanboi...LOL

flyingtoaster

And make sure you change your clutch fluid frequently or your MC will go out.

Great To Be Alive

One more quick question... as I've searched some of the threads where owners intentionally overfilled the tranny and had problems engaging 2nd or reverse etc. I pumped in the better part of 2qts of Honda MTF, then let it run out the fill hole and equalize for 10 minutes or so before installing the fill plug... so no intentional overfill. But if garage had a slight slope to it, it may have a bit more than spec if anything (based on the orientation of the car... it was on even height jack stands). Would this potentially contribute to a second gear engagement issue? I remember when I first pulled the fill plug when starting the procedure... nothing ran out at all, so I may be slightly higher than factory fill. Just wondered if it was worth popping the fill plug again with the car facing a different direction to see if some flows out.