Lately when the car is really warmed up I grind quite badly when shifting from first to second at high RPM. It is almost like the synchromeshers don't work. I tried moving my sear forward to be sure the clutch is fully depressed but with no success.

This is really disturbing at the least, especially when it is hot.

I guess no racing till I figure this one out.

Bobby

 

try changing your transmission fluid to GM Synchromesh Friction Modified.

You should be able to find the part number with a search

 

Synchros work only up to a certain level. Perhaps you are shifting too quickly. Try slowing down the 1st-2nd shift and see if it still grinds.

 

The 1->2 grind is VERY common among S2000s. Your best bet is probably GM Synchromesh Friction Modified, as Hokiemax suggested. Make sure it is Friction Modified, not the regular stuff. My 2nd gear was grinding 2-3 times per day on the original transmission oil, but after trying several different oils and clutch adjustments, I've finally cured it.

 

Bobby, you should also consider flushing your clutch fluid. This might also help. You've got an '02. It's probably time.

BTW, I've been told the Canadian part # for the GM FM fluid is 10953509.

 

I flushed mine after 5,000 miles and the pedal felt a little bit stiffer. No grinds for me at all

 

Welcome to the club. This is a common problem and is caused by a number of things. Firstly, you do need to change to a different transmission fluid. Redline MTL has worked for many (newer transmissions), Redline MT90 (in older transmissions), and many have recently found GM Synchromesh Friction Modified is the fix. This, and really concentrating on your 1-2 shift will alleviate the problem. Definetely bleed your clutch fluid as well.

 

I bought my '02 used with 29K miles and it did the same thing. The local dealer rebuilt the trans under warranty, and they relaced a lot more than the 2nd gear synchro.

Now it's a little notchy at low rpm but shifts like butter when I wind it up. If you're under 36K miles it's worth asking.

 

Mine worked great after changing the diff & tranny fluid

 

-My first transmission - bigtime problem = rebuild (replaced all synchros, bearings, oil pump, second gear, shift forks, seals ...).
-Rebuilt transmission - problem still there and eventually got worse = replaced transmission.

-New transmission - no problem at first, but after 4,000 miles on the tranny, I've had two minor grinds, one medium grind, and one 'not so subtle' grind.
Redline MTL has helped (and increased my mileage). I have a case of the MTL to share between my 2003 S2000 and Civic, after that's gone ... I think I may give GM Synchromesh Friction Modified a try.

Just installed the Pinnacle Brake system from Rick's and an '04 diff with 4.57 gears - I hope I don't have to screw with it for a while .