I have a 2002 C5 with the 6 speed manual. The car only has 64K miles on it, but it shifts like a 1949 dump truck. It is difficult to get into 1st when you come to complete stop with it being in 4th or 5th gear. Sometimes you can get into 1st only after putting it neutral, then into 1st. Also, it takes a great deal of effort just move the shifter handle from 1st to 2nd, or 2nd to 3rd, etc. It has a Hurst shifter, and I have changed the fluid and replaced with Royal Purple, but no real change. With my little to no knowledge on this transmission (I come from a time when the Muncie 4 speed was "hot stuff"), I suspect the syncros maybe broken. I live in the Atlanta Ga area. Anybody know of any "Corvette knowledgeable" people in this area that can look at it and possibly repair? Any other suggestions? Thanks.

 

 

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Hope you get some quality answers.

 

Holy Smokes.... I LOVE the way my C5 and C6 shifts.. Something is WRONG. We just have to figure it out what it is.

Have you ever lubricated the shift rod inside the shifter???



IF,,,,,,,,,, you put the trans in first with the clutch deperssed and REV the engine to approx 5000 rpm,, does the car start to move????

Have you done ANY clutch hydraulics maintenance, (flushing)

BC

 

With a different shifter in there, not sure what to suggest. First thought would have been to do a shifter alignment but with the Hurst in there, no clue how to do that.

 

My car shifts perfectly smooth but I have the stock shifter. I do suspect that your problems may be caused by your aftermarket shifter. But, there is no way to know for sure until you try going back to the stock shifter and see if it solves your issues.

PS: A large number of problems I read about on this forum are caused by aftermarket parts.

 

Most likely your shifter. I had a hurst, and had the same issues. I tried adjusting, different springs, setting the stops, etc. Very notchy shifting, and never felt confident shifting fast. I purchased a modified C6 Z06 shifter from RSD. It has a nice short throw, and precise/predictable shifting.

 

Have you lubed the shift yoke in the shifter box? They get stiff some times!!

BC

 

It's been a long time since I did this, so my description might be a little vague, but.....

Remove the shift boot and with the shifter in neutral, look at the shift rod that is on the left side of the transmission tunnel. There is a clamp that is attached to the rod, and a hole in the clamp and the rod. These two holes have to be aligned with each other, in order for the "neutral gate" of the shifter to be properly aligned.

For those of you who still have the OE shifters, that is what the "pin" that's clipped to the shifter is for. You loosen the clamp, and adjust it so the pin drops through the clamp and the rod. Then you tighten the clamp back up. Same procedure with an aftermarket shifter, except if you don't have the OE pin, you have to use something else that is a suitable diameter, such as a drill bit or allen wrench.

I've had a Hurst shifter in my C-5 for 10 years, did this adjustment when I originally installed it, and it's been fine ever since.

To the OP, good luck!

 

I also have a Hurst, and had similar problems. Try the Antivenom mod [do a search] its cheap and easy, may help. It did for me.

 

I also suspect poor intallation of the shifter or a poor 1st design---ALSO it even sounds like the clutch isn't fully dis-engaging when stepping on the pedal-so it shifts like a dump truck---Tyically that would only require to"bleed" the clutch fluid as you may have some air bubbles in the system---

 

I very much thank you all for the quick replies. I will do the antivenom mod, and bleeding the clutch system. If no improvement, I'll put the stock shifter back in. Thanks again...you guys are great!

 

Don't forget to check the shifter alignment too.

 

I have a 98 with basically the same problem, has a Hurst, but did this before installing shifter. (btw, MUCH better than stock) Hard to get into first sometimes, feels like its sticking on something, if I let clutch out a little, it will click int gear, also sometimes in 2nd at a stop. Will changing fluid improve this, or is there some other adjustment at the trans possibly?

 

I saw this post and have to ask what do you lubricate the shift rod with? Is spray silicone lubricant acceptable or does it require some other type of lube? I doubt mine has ever had maintenance done to it, and even with fresh fluid it feels a little rough going into and out of gear, which feels like it's probably because of a lack of lubricant. Since my short shifter purchase is being pushed back a few months I need to go ahead and do what I can to prolong the use of my stock shifter.

Thanks.

 

POOR SHIFTING MN6/MN12 transmissions can be traced down to a hand full of reasons.
I dislike the stock C5 MN6/MN12 shifter especially on the early C5 transmissions where the centering spring inside the transmission is lack luster. I prefer a shifter that contains additional centering springs inside the shift handle. The 2001-2004 C5s had improved springs inside the transmission.

Here are a few things that you need to check:

YES,!! If your transmission AFT fluid is dirty and thin, it can negatively affect shift quality. My 98 coupe MN6 trans notably improved shift quality just from a fluid change. NOTE! A fluid change will NOT repair mechanical damage. If you have a 97-98-99 trans, make sure that you use the CORRECT NON SYNTHETIC ATF.
2000-2004 can use synthetic ATF. AMSOIL (contact forum member SUBDRIVER) has a universal ATF fluid that is outstanding in all of our MN6/MN12 units!

PROPER CLUTCH DISK RELEASE: If your slave or master cyl is not 100% functioning properly and does not allow the clutch to completely release from the flywheel & Pressure Plate, shifting can and will be difficult. I STRONGLY! Recommend bleeding and flushing your master /Slave Cylinder!! Remove the intake manifold and lay across the engine and reach down behind the block and access the slave bleed fitting.. Get that NASTY crap out of the slave!

See this post. HIGHLY RECOMMENDED READ! It has some OUTSTANDING facts and tips:

http://forums.corvetteforum.com/c6-t...ur-clutch.html

My ZO6 clutch pedal would stick to the floor under moderate to full throttle shifts. Upon tear down I found the clutch/pressure plate and flywheel was in very good shape. The Master and slave cylinder however were FULL of crud (clutch dust). The Pilot Bearing was also in poor shape.

Bleed the clutch hydraulic system! Do the bell housing cleaning, trans fluid change.

Inspect the shifter and shift box. Make SURE that the RUBBER SHIFT BOX BUSHINGS that isolate the shift box from the torque tube are not worn or dry rotted! If you have a ZO6, you do NOT have rubber bushings! Lubricate the shifter box : Make sure that the four fasteners that secure the shifter to the box are properly tightened:



KIRBAN SHIFTER vs STOCK:


IF all that is complete and you still have shifting issues, you most likely still have a hydraulic system issue or the plastic shift fork pads are worn or the synchros clutch cones are worn.


Lets us know what you think and what you find.

BC

 

Good advice above.

Before you spend a lot of money on pulling the tranny and doing things like replacing shift linkages, you might try the simple and easy first. As Bill mentioned, I use this in my 02 Z06 at the track:
AMSOIL Torque-Drive Synthetic Transmission Fluid (Product Code ATD1G)

I’m happy to offer dealer wholesale prices, about 25% below retail, for forum members via the AMSOIL Preferred Customer Program. Drop me a PM if interested.

 

What does your clutch fluid look like?? If its not clear, then this can also create problems also.. Sounds like you have more of a shifter issue, but this is a great thread to look at also http://www.rangeracceleration.com/Clutch_Care.html

 

Thanks again for the replies. I will flush/bleed the clutch system, and see if that helps. I have replaced the transmission fluid with Royal Purple ATF. Any problems with that?

 

I will try clean fluid and bleeding, also change trans fluid w/ non-syn, see if that helps. What would worn syncros do? Car has 84K on it, I wouldn't think they would be worn out.