Trans/Clutch issue [Archive] - SmokinVette.com Forums

powerlabs

01-05-2010, 06:28 PM

2007 C6 2LT
22k miles

I've got some mild performance upgrades but nothing to speak of.

The issue is I'm trying to decide whether my trans (T56) or clutch is going.

Recently when I shift gears it takes some effort to get in and it's like it clicks going into every gear. I just got through rebuilding a t56 for a friend of mine but I can't imagine all the synchs going out at once. Any ideas. It doesn't grind when going into gear and my clutch isn't slipping.

:wtf:

Ummm... A few thoughts:
First and foremost, your car is a 2007, so you have a C6 Z06 clutch. Mine was a 2006, so I had the weaker C6 spec clutch.
The worst mod I did was replace my factory clutch. At 50K miles there was absolutely nothing wrong with it and it was holding down my 600RWHP / 518RWTQ supercharged power on 305-width R-Compound tires like a champ. I figured it was going to slip on the drag strip (very likely) so I replaced it with 50K miles.
Not only did the replacement slip on the drag strip, but it also came with a stiffer clutch pedal, some chatter that took MONTHS to go away, and an ENORMOUS bill... I think the labor alone was a month and over $2600. The clutch went in, was defective, had to come out, the replacement arrived broken, the 3rd replacement finally stayed in the car, I had to pay for 2 full clutch swaps and deal with all the downtime waiting for things to arrive.
So, there is the clutch for you. If you want to do something to it put a remote bleeder and call it good; at 22K miles unless you are the worse driver in the world it has to be fine, and the clutch in your car is the only one I would consider running unless you want to become a drag racer and/or want to make a lot of power from your car (F/I power).

Now, regarding the gears. The 1st gear synchro on most cars is problematic; you have a big jump in gears there coming down from 2nd and on the Tremec T56 it is fragile and you should avoid going down into 1st gear from 2nd while the vehicle is moving. It IS possible that you may have damaged it. The repair is not easy and it won't be cheap. I was quoted $1000 just to get the transmission off and *look at it*, before we even started replacing parts.
My advice for you is the following; drain your transmission oil, it is very easy with the back of car up on ramps or jackstands using a 1/2" breaker bar on the drain plug. Remove the filler plug first though just in case you drain it and then can't get the filler removed and then you're stuck with an empty transmission.
After you've drained your transmission refill it with Royal Purple Synchromax. I've used it in all my cars and it always seems to make an enormous difference. On my C6 it almost felt like a new transmission. Give that a try. If it still grinds, then consider that rebuild. Also flush your clutch fluid at the same time if you've never done so.

Now, as to why every gear seems to click in... Remove your center console trim and look at your shifter; check that it is in good condition and all bolts are tight. If the shifter starts to come lose that can happen also... All your synchros have not gone bad, something else is happening. Is it hard to get into gear with the engine off? That would eliminate the possibility of it being a clutch issue.


SmokinVette.com Forums > Corvette Forums > C6 Corvette Forums > C6 Tech & Performance > Trans/Clutch issue PDA : Trans/Clutch issue gon2fast 01-05-2010, 04:25 PM 2007 C6 2LT 22k miles I've got some mild performance upgrades but nothing to speak of. The issue is I'm trying to decide whether my trans (T56) or clutch is going. Recently when I shift gears it takes some effort to get in and it's like it clicks going into every gear. I just got through rebuilding a t56 for a friend of mine but I can't imagine all the synchs going out at once. Any ideas. It doesn't grind when going into gear and my clutch isn't slipping. :wtf: powerlabs 01-05-2010, 06:28 PM 2007 C6 2LT 22k miles I've got some mild performance upgrades but nothing to speak of. The issue is I'm trying to decide whether my trans (T56) or clutch is going. Recently when I shift gears it takes some effort to get in and it's like it clicks going into every gear. I just got through rebuilding a t56 for a friend of mine but I can't imagine all the synchs going out at once. Any ideas. It doesn't grind when going into gear and my clutch isn't slipping. :wtf: Ummm... A few thoughts: First and foremost, your car is a 2007, so you have a C6 Z06 clutch. Mine was a 2006, so I had the weaker C6 spec clutch. The worst mod I did was replace my factory clutch. At 50K miles there was absolutely nothing wrong with it and it was holding down my 600RWHP / 518RWTQ supercharged power on 305-width R-Compound tires like a champ. I figured it was going to slip on the drag strip (very likely) so I replaced it with 50K miles. Not only did the replacement slip on the drag strip, but it also came with a stiffer clutch pedal, some chatter that took MONTHS to go away, and an ENORMOUS bill... I think the labor alone was a month and over $2600. The clutch went in, was defective, had to come out, the replacement arrived broken, the 3rd replacement finally stayed in the car, I had to pay for 2 full clutch swaps and deal with all the downtime waiting for things to arrive. So, there is the clutch for you. If you want to do something to it put a remote bleeder and call it good; at 22K miles unless you are the worse driver in the world it has to be fine, and the clutch in your car is the only one I would consider running unless you want to become a drag racer and/or want to make a lot of power from your car (F/I power). Now, regarding the gears. The 1st gear synchro on most cars is problematic; you have a big jump in gears there coming down from 2nd and on the Tremec T56 it is fragile and you should avoid going down into 1st gear from 2nd while the vehicle is moving. It IS possible that you may have damaged it. The repair is not easy and it won't be cheap. I was quoted $1000 just to get the transmission off and look at it, before we even started replacing parts. My advice for you is the following; drain your transmission oil, it is very easy with the back of car up on ramps or jackstands using a 1/2" breaker bar on the drain plug. Remove the filler plug first though just in case you drain it and then can't get the filler removed and then you're stuck with an empty transmission. After you've drained your transmission refill it with Royal Purple Synchromax. I've used it in all my cars and it always seems to make an enormous difference. On my C6 it almost felt like a new transmission. Give that a try. If it still grinds, then consider that rebuild. Also flush your clutch fluid at the same time if you've never done so. Now, as to why every gear seems to click in... Remove your center console trim and look at your shifter; check that it is in good condition and all bolts are tight. If the shifter starts to come lose that can happen also... All your synchros have not gone bad, something else is happening. Is it hard to get into gear with the engine off? That would eliminate the possibility of it being a clutch issue. gon2fast 01-05-2010, 07:10 PM I didn't know the base C6 had the Z06 clutch. If I have to rebuild it it's not a big deal because I have a lift and have done several T56's. It does click with the engine off so I guess you're right about the clutch. I bought the car used with 18K on it and know how to drive..on the other hand, who knows about who drove it before me. I'll check the shifter but I don't know. It doesn't grind going into gear but it does click into every gear so I'll check the shifter. Who knows. gon2fast 01-06-2010, 09:41 AM Ok. I just pulled apart the shifter and double checked everything. Alignment is perfect. No interference and the bolts were tight. I just put it back together and it's still clunky. I'll try the trans fluid tonight. Any other ideas.