ViperT4

iTrader: (1)

I'm having a problem with my transmission I hope you guys can help me diagnose. Car's an 04 GTO 6-speed with 46,000 on her. When the car is cold and I first start driving I have to be slow and super deliberate with my 1-2 and 3-4 shifts or else I get a real bad grind. When it happens I put the lever back in neutral right away and then into the gear I wanted and it goes just fine. The 2-3 shift is not the smoothest but there's no grinding.

Once I've been driving for 10 minutes I can shift normally, but they still are rough. I can still feel the metal-on-metal and I can tell that 2nd wants to grind but whatever gets caught up when it's cold gets out of the way quick enough in the warm transmission to not grind. I do not abuse this car other than two 3500 RPM starts and the occasional hard shift at WOT, but I am the third owner and bought it 6,000 miles ago. Any help here? I love my baby and don't want another day worrying about what's wrong with her, I just want to know!

thesource

iTrader: (60)

Does this happen in all weather conditions or only when its cold outside?

ViperT4

iTrader: (1)

It didn't happen in the summer when I got the car. I'm in Milwaukee and the season is starting to turn. It hasn't been crazy cold yet though, 20s-30s at night, 40s during the day.

thesource

iTrader: (60)

Its probably a hydraulic issue. Once the fluid warms up from the heat the engine is putting off, the fluid flows better. You can try to insulate the hydraulic clutch line from the elements and see if it helps. Down here in Texas, we always get complaints from people about their hydraulic clutch systems when the temps drop outside. Fortunately, its not a big issue down here.

ViperT4

iTrader: (1)

Just wanted to say thanks to thesoure, now that it's warming up again it's running great!

Dan

iTrader: (1)

Not to hijack, but mine shifts better when it's warmed up but under hard acceleration I get major grinding trying to shift. Can it be the syncros? I already have the drill mod, adjustable master. when I 1st got my Centerforce of course it wouldn't shift at all, so I am thinking I ruined the syncros before i did all the supposed fixes(Drill mod, adjustable master) to get it to shift.

yosteff

iTrader: (1)

Just get a SPEC stage 2 and it seem to do the same! It is hard to shift in any gear and i CANT go in reverse!!!!! New clutch , new 2001 and slave , drill mod and adjustable master cylindre!!??

Wesmanw02

iTrader: (4)

If all the gears are hard to shift into and you can't get into reverse, the clutch is dragging.

You may need a slave cylinder shim, or you could try adjusting the master cylinder. Typically Spec clutches end up needing slave cylinder shims though, thats probably the issue. The throwout bearing isn't extending far enough forward to completely disengage the clutch.

As for notchy shifting and grinds when cold, I've found its indicative to T56's which have some wear on the synchros. Mine will be very uncooperative when its 30 degrees out, but if its 60 out, it will shift like butter. My friends GTO is the same way, shifts much better when warm.