tryhardriceboy

Hi all,

I'm a long time lurker and first-time poster, so please be gentle!

About a week ago, I did the 3-fluid change (engine, gearbox, diff) in my stock '99 S2000 with 110,000km (about 68k miles) on the clock, and I've just started to notice some really unusual noises coming from my gearbox.

The main issue is that I hear a loud noise in 2nd gear only, similar to this:
http://www.youtube.com/watch?v=r6j85AH7T3Q

All other gears sound normal at 'city' speeds (under 60kph/35mph), but I can hear some new noises if I go to a quiet area such as a parking lot. There's a 'ticking' that varies with engine speed if I leave the clutch engaged in neutral, which disappears when I push in the clutch pedal, and there's also a similar 'ticking' noise if the car is rolling downhill whilst in gear, and this increases frequency with vehicle speed. I'll record a video if anyone is curious.

I've only driven about 20km since noticing the problem, and am not planning to drive it further until I work out what to do next.

The gearbox has always been a little notchy going into 2nd gear, but it's not been bad enough to worry about. Even with the above issue, there's been no change in shift quality (even into 2nd gear).

I guess this all means that my gearbox is going to need some work, but there are a couple of things I'd really appreciate some advice on:

* I changed the gearbox oil whilst the car was on a slight incline (front wheels about half way up a set of ramps). I still managed to get well over one litre/quart of fluid into the gearbox - let's say it was about 1.5 litres/quarts. Is it possible that the angle of the car prevented me from getting enough oil in to the gearbox, and I've killed the bearings through oil starvation? I've read through the gearbox oil change 'howto' thread and noticed a couple of commenters indicated that they had performed gearbox oil changes with the car on ramps too. I hope it's just a random failure rather than being caused by my incompetence!

* I'd appreciate some opinions from people who've been in similar situations about what I should do to get my S back on the road without spending a fortune. The car isn't my daily driver so I don't need to rush. I like to do my own work on the car but have never attempted a major job like a transmission or clutch previously. If anyone could give some input on the following I'd really appreciate it:

- Is a transmission rebuild something that I should consider doing myself? I have the workshop manual and don't need the car working straight away. I also have access to borrow a hoist or press if needed.

- If I take the gearbox to a specialist, should I insist on them using genuine Honda parts, or are good quality aftermarket components generally OK?

- I'm a bit reluctant to install a used AP1 transmission because it might suffer from common issues such as 2nd gear grind. If I purchase a used, low mileage AP2 transmission to install myself (without rebuilding it) would that be a safer choice, or is that still quite risky?

- I read on the S2KI forums that if I purchase replacement synchros from Honda for my AP1 gearbox then they will be the new carbon type - is that true?

Thanks in advance for all of your help.

Trev.

99SH

You're getting way ahead of yourself. Sounds like it may be as simple as a throw-out bearing.

If I were you, I'd drop the tranny and inspect the entire clutch assembly particularly the disc, TO & pilot bearing.

afzan

tranny fluid capacity is 2 quarts/liters.. If you only filled 1 or 1.5L then thats the problem

s2000Junky

I was just going to say. Your trans may have been on the way out already and shorting it on fluid speed up the process. At any rate its been my experience that rebuilding these trans cost more then finding a good lower mile used one and swapping it in. I'm on number 3 myself. You could spend $1500-2000k just in parts an labor rebuilding, not including labor in removal/install. Or you could picked up a used ap1 trans with around 50k miles for $600-700 and about that much more for total labor. If you drop off your car at Honda and say "here fix it", it will cost you the most probably $4000. Don’t do that.

iamxpl

the tranny does not take a full 2 qrts IIRC. it should be just about 1.8 qrts. fill until it starts to drip out. given that the car is leveled.

tryhardriceboy

Hi again, and thanks for all the replies so far.

My neighbour (a retired mechanic) let me borrow his hoist for a closer inspection, which revealed some good news and some bad news:

The good news is that there is plenty of oil in the transmission, so the timing of the failure must be coincidental. I feel a little better about the whole situation now that I know the problem wasn't entirely self-inflicted.

The bad news is that the noises appear to be coming from the input shaft bearing (we used a stethoscope to check). This was also found to be the cause of the noise in the YouTube video I linked to.

Obviously it looks like the transmission will need to be removed from the car, but I'm still unsure as to the best way to proceed. I think I'd prefer to have my existing gearbox repaired rather than going with a used unit, as mine's pretty smooth through the gears (just slightly notchy in 2nd) and luckily I've never had any clutch buzz symptoms at all. I'd be a bit disappointed if I got a used unit with a grindy 2nd gear and major clutch buzz!

I'd really appreciate a little advice on the following from someone (maybe Billman if I'm lucky?!) that has rebuilt a few of these gearboxes before:

* 109K kilometres / 67K miles seems quite soon for a bearing failure - I drive sensibly 90% of the time and always change the fluids early. My old Prelude travelled 400K kilometres / 250K miles before any gearbox bearings got noisy! Is input shaft bearing failure a common issue in the S2K?

* If it's a common issue, is there anything that can be done to improve durability, short of switching to an AP2 trans? Is it possible to improve lubrication of the input shaft bearing, or can I upgrade to higher-quality bearings?

* If bearings or even synchros need to replaced during a rebuild, should I stick with OEM or are there some good/better aftermarket options?

* Does anyone know if the OEM bearings and/or synchros have been revised/improved since the car was new? I read on the forums that AP1 synchros purchased from Honda are now the carbon ones - is that true or urban legend?

* How does Billman manage to overhaul a gearbox 'while you wait'?

* If I end up sending the gearbox to a transmission specialist who hasn't rebuilt an S2K box before, is there anything special they should know?

Sorry for all the questions - I've tried using search but seem to get conflicting answers. All help and advice is really appreciated!

Trev.

tryhardriceboy

Bump! Would really appreciate some advice on the above. Thanks!

Cyrax

I'm in a slightly similar situation with my gearbox and here is what I have determined; A used tranny will be a faster way of getting your car back on the road. The downside is, unless you do a complete tear-down, and mic every component, there is really no way of fully gauging the health of the tranny you will depend on to get you from A to B. This could potentially lead to further repairs in the future which may require the investment of more time and resources for parts and labor to correct.

If convenience is your top priority, not that there is anything wrong with that, then your best bet is to swap in a used gearbox, preferably from a trusted source. If piece of mind and component longevity is foremost in your mind, then a rebuild would be prudent.

For what it's worth I've priced all of the components, including clutch and rear main seal (one might as well do these whilst the tranny is out) at $3391.55, and that's for everything except the main, counter, and secondary shafts themselves. As for labor, I'm estimating for $1000.

Of course this puts the grand total perilously close to the price of a brand new AP2 gearbox at $4305.56. The upside here, is you don't have to pay for the labor of rebuilding a tranny, you get a warranty from Honda which is good, (as long as the stealership will honor it, should you go that route), faster turn-around time on your car, and ultimately, peace of mind knowing that the tranny in your car is absolutely top notch and ready for duty.

I've also heard of the new AP1 synchros being carbon as well, but I am still seeing two different part numbers between the AP1 and AP2 synchros. I'll have to look into that and I'll let you know what I find. With regard to the bearings, if you use OEM parts where it counts, such as here in a tranny, you should not have any reason for concern

I hope I've helped you with your decision in some small way. If you'd like to see a copy of the price list I've compiled, I'd be happy to send it to you.

tryhardriceboy

Hi Cyrax,

Thanks very much for your reply - sorry to hear your gearbox is playing up too!

I managed to find a local mechanic that's familiar with S2000s, which was reassuring, so I think I'll end up giving the car to him so he can rebuild the gearbox. I don't need the car back on the road straight away, and suspect if I buy a used box I'll end up with clutch buzz or a notchy 2nd gear.

Slightly off-topic, but your post highlights the difference in how Honda's Australian customers are treated! I went to the dealer to enquire about a new gearbox, and they didn't seem too interested in helping at all. The guy just said "an S2000 gearbox is about $7000 ($US6300) plus $1500 ($US1360) to install", without even looking anything up on his computer. I asked if they often get S2000s in the dealership for servicing, and he said 'nope - hardly ever'. I'm not surprised! On top of that, the guy said all S2000 parts are usually shipped ex-Japan, and I'd have to wait at least 4 weeks to get them.

The mechanic I found didn't seem too keen on having my S taking up room in his shop for 4 weeks, so I'll have to pay for a tow truck (x2) so the car's not in his way whilst he waits for parts!

Just for comparison's sake, an AP1 flywheel in Australia is $445 ($US405) vs $US268 if I buy from the US! It's even worse for brake pads - over $300 here vs $45 in the US! [end rant]

If anyone else can shed some light on the AP1 carbon synchro query it would also be appreciated!

Thanks,

Trev.

iamxpl

WOW.. thats some crazy prices. good luck to your endeavors and please keep us posted on the outcome. i personally would have sourced out a second hand gearbox. mightve been the cheaper and faster way although could be a gamble.

clutch buzz comes from the clutch assembly. something to do with the old style clutches supplied early on in the years. i believe this has been remedied. while the box is out now would be a good time to address some other things like the rear main seal. i know you mentioned that the mechanic is familiar with the s2000, but ensure he lubes all the proper points in the TO bearing guide and TO bearing itself. its been well documented here on this sub forum.