Bill Dearborn

Actually the transmission and diff aren't in one package. The diff, a spacer unit and the diff are bolted together. The trans and diff are two totally separate units and are sourced from different suppliers, Tremec for the transmission and ZF for the diff. It really isn't a transaxle.

Bill

VatorMan

I'd say you need to investigate what a TRANSAXLE is and how it relates to a C6 Corvette. Plus you are really showing your ignorance. Maybe you should go back to a Porsche.

Dirk Miller

Just find someone at the track that has a MGW in their C6 and ask to drive it. A comparison is in order here. Where are you located?

CyberGS

A second mention on the fluid, interesting to know - it was a pretty hot day yesterday and as many of you probably have experienced, the heat coming out of the footwell gets up there so the clutch area on the opposite side would obviously be pretty brutal. Maybe this is something to consider as well. I had the issue early in the morning, but that said, the car came from Las Vegas so maybe somewhere sitting it traffic on a 110 deg day the fluid boiled and I am now dealing with an issue that I don't realize is new as I didn't have it from new to know what the shifting was like on day 1.
Interesting thought on missing the shifts in high G turns - the stock seat of course don't hold me like a race seat and I had a lot of motion on the track. My left elbow was getting sore near the end of the morning as I was leveraging off of the door to try and keep in the seat on right handers. Two spots where I had this issue I would short shift as it was going into a turn, and I figured maybe short shifting quickly was screwing with the synchros but there may be something there - maybe I was just leaning a bit and even tho' I was palm only on the shifter it was just enough to pull it off gate to the left.
I will check these out. That is more than one vote for MGW.
I am in CO but I would be surprised if someone actually would let me drive their car not knowing me - I know I certainly wouldn't. That said, I checked my local dealer but they don't have any C6s let alone a Z06 as I wanted to just drive another new one and see if there was a noticeable difference or if the synchros felt smoother or more exact.
Well, apparently you should sell your car and buy a Porsche so you can shift smoothly. Sorry, couldn't resist.

Overall I am a bit suspect of my trans - it really is notchy and frankly doesn't feel like modern synchros. Slow shifting piddling around town I don't have any issues, but on the track it was bad.

So let me ask these questions:

1. For those that don't have a shifting issue, can you shift from 2-3 really fast and not feel the synchros push back? I can feel the synchros push back on mine in pretty much any gear change if I do it quickly, so even if I "make the shift" by not getting trapped in the gap between 1 and 3, I still feel a lot of drag in the synchros. More than other modern cars such as a modern 6spd Porsche or Mustang.

2. I know fluid can have a dramatic effect on how well the synchros will work - are there any good fluid recommendations from those that track their cars? I expect GM to save a few bucks and put in "really good" fluid but maybe not the "best" fluid and maybe there is something you guys have found to be better?

Ludedude

My last manual car was a 2001 S2000 and that had one of the nicest gearboxes and shifter feel that I've ever driven. The box in the vette is not quite as crisp feeling while shifting but then again it has to be stout enough to deal with gobs of torque.; I expect it to have different characteristics than some wimpy import box. Overall I find it to be quite good though and have never missed a shift on track (stock shifter etc.).

I just put Redline D4 in the transmission this week in preparation for a trip to Laguna in a few days. I don't really discern any difference around town but the stock fluid had 26K miles on it so time to change. We'll see how the new fluid is once things get heated up in the box.

SouthernSon

Quartermaster clutch pack in mine and I can shift so quickly it sounds almost sequential like. ..seriously...

Instead of busying yourself with posting complaints I would suggest browsing the web for information on track performance of the vette. The last Porsche dealer sponsored track day where I instructed would not let us vette drivers put our cars on track. Bless their hearts....

RX-Ben

+1.
Check shift rod alignment or a bad bushing in the shifter base, nearly certain that something is off as it will lead to the problems that you are describing. A misaligned rod can lead to other problems once you start forcing things, like a bent shift rod, which will then lead to a internal trans problems.
Best shifter I have used is a C6Z shifter and I would avoid an aftermarket unit.
I like the feel of my corvette's box better than my S2000's - more precise and substantial.

froggy47

Mine is a c5z 2004 but there are issues that carry forward so I am told.

Don't rush the syncros, feel them & push thru them, but let them have time to work, don't rush the shift. Your (let's say everybodies) technique will suffer towards the end of a session, ESPECIALLY fighting to stay in a stock seat. You are fighting to stay in the seat and your arm that is throwing the shifts get's tired & get's twisted up due to fighting the seat. Why it is so important to let the centering springs do the work.

I strongly suggest Redline d4atf in the tranny and do a shifter alignment procedure at least annually, it's easy to do. I also vote for the stock c6 shifter (thinking of getting one for my c5z).

Put in a really high temp clutch fluid, the oem clutch hydraulics do suck.

Rev match going down of course.

c5_4_me

Lacking mention in this thread is the fact that the C5/C6 manual transmission is a Tremec T56/TR-6060 and can be found in plenty of other vehicles. Granted, the front engine/rear transmission configuration is rather unique to the Corvettes, but the basic box is found in Vipers, Mustang Cobras, Aston Martins, Camaros, GTO's etc...
http://en.wikipedia.org/wiki/Borg-Wa...6_transmission
So to the OP, there is likely either a problem with your car, or with the driver, as the transmission is actually quite highly regarded by enthusiasts of several makes of non-P-car automobiles.

crimlwC6

I dislike the c6 base shift box and felt the MGW was a big step up. When I sold my c6 I swamped shifters with a friend I sold the mgw to; it felt terrible to me .In my 99 FRC track only car I have kept the stock shifter and use a pretty tall shift ****. Different strokes for different folks but I'm pretty sure I'm not a brainwash victim. One thing I don't think was covered was heel toe shifting. To the OP are you rev matching your downshifts?

not08crmanymore

After they changed tranny's in 2008,the shifting has been very nice and easy.Maybe you should go to Bonderaunt (sp?) and take some lessons...

crimlwC6

I had an 08. I've run Bondurant's course a couple of times.

redtopz

+1 +1

I've been running an RPM C5 transmission with a C6 or C6Z shifter for years and it shifts as fast as I can move my right arm.

Hat_Trick_Hokie

Exactly why I bought the MGW. Tall handle with revised pivot point, which makes the throws slightly shorter. However the real purpose of the upgrade, is the stiffer on-center feel, with more positive engagement in every gear.

sleeperstyle

change the fluid in your clutch reservior after every session. if i don't do this at least every other session i have problems downshifting into 3rd, which is aggravating. i know it is my fluid because i can feel it in the pedal/ pump the pedal and it is ok.

the clutch hydraulics in corvettes suck, plain and simple. i have a mgw with their lower box, that doesn't matter if the fluid is cooked

erichg1000

My shifter is completely stock on my 06 Z and it shifts very smooth and very fast. I've never had a problem. Well last weekend at HPR I did accidentally go from 3rd into 4th instead of 2nd on turn 5 (I think it was 5) while downshifting. But that only happened once and it was the first time. Friday night at Bandimere I was shifting faster than normal while bracket racing and had no issues. A racing seat and harness will probably help be more accurate.

crimlwC6

https://www.youtube.com/watch?v=6DcgdClBRIs&feature=youtube_gdat a_player
Here is a video showing my shifting. I miss the 3 to 2 revving on one of the first turns but I have a light clutch and fly wheel that helps mistakes. The mgw iirc does take getting used to. You have to push hard into two but once used to, no missed gears.

CyberGS

I have a lot to chew on which is good. I clearly ruffled some feathers; I was really PO'd when I put this up I didn't expect this from a Tremec trans, especially having a fair amount of experience with them in Mustangs.

I do rev match on downshifts to answer that question. Indeed, I never had an issue missing shifts going from 3 to 2, just maybe feeling the synchros a bit. I have some vid of a lap I was going to post up on Youtube but they have made significant changes and want me to fix my account to a new name and create a whole new channel, not sure why that is. In the fast lap I was attempting to post (BTW, only 3 seconds off the times the multi-year track champ in quite a few classes that is also an instructor said he can run in a Z06 on the run flats and 5 seconds faster than the fastest of any of the other Zs I have seen out there so I consider that pretty solid for my first track day with the car ) you would be able to hear one section I really rev match on the downshift as I am going from really fast to a slow sweeper and I shift before entry as I have to climb a hill up out and need the mechanical advantage. It is a bit of a zinger on the engine revs

Minus the 2-3 issue I am having, the car is a beast even on the run flats. That is only 8 seconds off the average pace I ran in my other car with slicks and so forth (tho' pretty old tech in its defense) which I consider pretty solid. Keep in mind, the 1:55s average laps I ran in my other car was 2 seconds faster than the SCCA Super Production record of 1:57.4 that was another V8 914 with 150 more HP and also 2.5 seconds faster than the T1 record set my the aforementioned champion in his Corvette. My fastest lap ever was a 1:53. That means the stock Z06 on run flats can be within 3-4 seconds of those SCCA records so that is cool. With slicks and a cam I feel I could put this car back at near the 1:55 range, so while not quite what I had at a 1:53 best, pretty solid for something I could turn the A/C on and drive home

I will check out the trans fluid recommendation as well and will get some new clutch fluid in there. Certainly sounds like I need to check into the linkage and bushings.

CyberGS

Nice vid, thanks. I can say that you grip the shifter way more than I do and don't have issues shifting, maybe it is the MGW, but if you can have that much input and not have an issue, I am thinking it is my trans or linkage. At 5:00 and 5:15 for example, you wrap your hand completely around the handle and shift 2 to 3. I literally only push forward with my palm, my fingers aren't even involved in the upshift. Today at lunch I went on an open section of road nearby, hammered second in a straight line to guarantee no lateral Gs, and then "palm only" shifted to 3rd and sure as hell I got stuck between 1 and 3.

Track-wise, you have a similar situation to what I have - the track is nearly all 2-3-2 shifting. I get into 4th on one long stretch up to 135mph, then right back down to 2 and 3.

I also have every other Friday off, last Friday being the track day, so in two weeks I can road trip out about 40 miles and there is a dealer out there that is noted as the major Vette dealer in CO and where I sold my GS. They also sponsor and maintain the T1 GS the champion drives so I am also going to set an appt with them to inspect the shifting and linkage, and hopefully get to drive another Z to see if I have the same problem (therefore I am the problem) or if they agree the trans is a problem. Should all be covered under warranty anyway. Then they can let me know what has been done (or not done for that matter) to the T1 car. It was built by Phoenix Racing so they may not know all, but they maintain it so hopefully they know by now

quick04Z06

Cyber GA: Find on this forum Ranger's clutch fluid change for the Corvette and learn to do it religiously.

Second, change out your trans/diff fluids in the rear. I would suggest talking to SubDriver (C66 Racing) of the forum about his AMSoil products. He both races and sells the product. He will not steer you wrong. Also, He or David Farmer might help you with some adjustments to the shifter itself.

Corvettes are not snick-snick boxes, but I have found them precise on the track. They are pretty balky when cold, but much better when warm, like you get at the track.

Remember, being greasy fast with the stick isn't so necessary on the shifts when you have that big engine to make up for lost time. You'll get faster with the box with the foregoing and more seat time in this particular car....