C6 Manual Shifter Adjustment

eboch · 07-22-08, 02:28 PM

Hi;

I recently changed the clutch in my '05 Z51 changed (to a Z06 clutch). As part of this, the shifter & linkage get partrially taken apart. This all worked out really well as far as the clutch is concerned. However, I now have a bit of trouble shifting into first (either at a stand still or slow roll)

It feels a bit like the linkage is blocking/binding or not quite "aligned". There is no noise or grinding. If I move the shifter across the center of the shift pattern, or engage another gear, it then usually allows me go into first afterward.

There is a shifter adjustment on the shifter base, can this have an effect on the shifter engagement/operation? if yes ... any tips on how to make these adjustments ... or any other possible shifter/linkage adjustments?

Does anyone know of any "wear" items in the linkage that might need replacement?

Thanks
eboch

c4c5specialist · 07-24-08, 02:41 PM

HI there,
Not usually any wear.
Adjustments are KEY.
And the shifter would have to be removed to change your clutch.
Readjust the shifter.
Allthebest, c4c5

eboch · 07-25-08, 09:50 AM

Took the console apart and took the shifter out. The only place I could see any "adjustability" was in the attachment to the linkage ... there is a colar/clamp fitting to the rear of the shifter control box (pretty obvious when you look at it, it has a torx screw). This is the main connection between the shifter control box under the shifter and the linkage which runs to the transmission. In my case this fitting was loose and therefore the shifter was not rotating the linkage properly. Loosening this and moving the shifter you can see that different linkage shaft rotations can be acheived. It does not seem to have a lot of play when loose, but it does have some. Adjusting this a few times, I was able to get very smooth gear shifting and perfect "H" centering between 3rd and 4th. The "balance" here seemed to be to get the right amount of linkage rotation to catch 1st & 2nd .... as well as reverse on the other side of the shifter throw. Then check that the shifter also sits nicely between 3rd and 4th without any left-right pushing. I then checked the smoothness of the 2nd to 3rd transition. It took a 2 or 3 adjustment cycles to get it to a good place ... took 5 minutes.

I drove the car last night and again this morning. Shifting beautifully. probably smoother and more precise feeling that it ever did previously.

c4c5 ... are there any other shifter adjustment points to be aware of?

regards
eboch

PS: I see a lot of posts related to difficultied with 1st gear, clunky 2nd-3rd shifting, etc .... I wonder how many of these can be solved with this adjustment (?).

c4c5specialist · 07-26-08, 06:24 AM

Virtually ALL shifting concerns can be traced back to a misadjusted shifter.
Did you push the PIN down before torquing the fasteners??? That is how it should be done.
Allthebest, c4c5

eboch · 07-28-08, 09:13 AM

C4C5;

...you are referring to the "L" shaped pin at the front of the shifter control box ... correct?. Yes this has to be properly inserted to re-assemble the shifter onto the control box in the correct position .... but I did not see any adjustments associated with it. Did I miss something?

eboch

c4c5specialist · 07-28-08, 10:14 AM

HI there,
Yes, the L shaped pin is for the actual adjustment to be perfect.
You place the car in neutral.
Loosen the 3 fasteners.
Push the PIN ALL THE WAY DOWN>
Torque all 3 fasteners, the clamp first.
Pull the pin back up and verify shifter operation.
Allthebest, c4c5

eboch · 07-28-08, 11:39 AM

C4C5;

..yes I think I did this ... but more by chance than through planning (!). My shifter seems really well aligned now.

I focused more on the clamping collar to the rear of the shifter control box .... where the linkage to the transmission is connected. I found a lot of improvements in the shifting with very minor adjustments here. It seemed quite sensitive.

Regards
eboch

fenderowner · 07-31-08, 01:24 PM

Quote:

Originally Posted by c4c5specialist

Virtually ALL shifting concerns can be traced back to a misadjusted shifter.

New here, but not new to the C6. Have an '05 Z51 MN6, also, and have a shifter question. I occasionally have trouble shifting into first after stopping, shifting into neutral (while waiting in traffic). On another forum, the common consensus seemed to be that this was due to the "robustness" of the gears in the MN6 tranny, and that GM's position was that if your problem occurred x% of the time, they would go into the tranny and replace a shim or some part that was better machined to ease this problem.

Your post, however, infers that I might just have an adjustment problem, which I would MUCH prefer over letting GM tear apart my tranny (and I have no desire to keep track of how often this happens).

Any thoughts or help would be greatly appreciated!

eboch · 07-31-08, 02:38 PM

I've also seen comments about the gear cogs not be chamfered, etc .... thus impacting how first gear engages. I cannot comment much on these possible "design" issues. .... I can only speak to my experience.

In my case, before I upgraded my clutch, I'd have into-1st shifting difficulty ~ 20% of the time ... particulalry at a standstill or slow roll. Running through another gear and then into 1st would usually allow the into-1st shift to happen.

After the clutch upgrade, into-1st shifting was noticably worse (...the subject of this thread). Sometimes I could not get it into 1st and had to launch in 2nd.

After I did the shifter adjustments, the into-1st shifting problem is 100% gone ... no work on the transmission gears, etc was done. In fact the whole operation of the shifting is just a lot crisper and much more "precise" feeling .... without any "odd" behavior. Additionally, the notorious 2-3 shift is really easy to hit right.

eboch

fenderowner · 08-01-08, 01:01 PM

Quote:

Originally Posted by eboch

I've also seen comments about the gear cogs not be chamfered, etc .... thus impacting how first gear engages. I cannot comment much on these possible "design" issues. .... I can only speak to my experience.

In my case, before I upgraded my clutch, I'd have into-1st shifting difficulty ~ 20% of the time ... particulalry at a standstill or slow roll. Running through another gear and then into 1st would usually allow the into-1st shift to happen.

After the clutch upgrade, into-1st shifting was noticably worse (...the subject of this thread). Sometimes I could not get it into 1st and had to launch in 2nd.

After I did the shifter adjustments, the into-1st shifting problem is 100% gone ... no work on the transmission gears, etc was done. In fact the whole operation of the shifting is just a lot crisper and much more "precise" feeling .... without any "odd" behavior. Additionally, the notorious 2-3 shift is really easy to hit right.

eboch

Sounds like my exact situation. Think I'll remove the console and check out the linkage adjustment/collar you mention above. Thanks for the tip!

ggsomers · 08-30-08, 11:02 AM

I had my C6 into the dealer 3 or 4 times to correct shifting into 1st & 2nd problems and they told me that the issue I was having was normal. I then decided to use the internet to see if others were having the same problem. After reading this "Thread" and making a copy and taking it to the dealer I now have perfect shifting into all gears. The dealer had replaced my linkage at about 16000 miles and my shift probems started then. I had a few problems shifting from 1st to 2nd prior to the linkage change. My dealer said they did not have access to this type of info when I showed them these comments. Thanks for the advice because my C6 is better than ever.
HappyC6

Quote:

Originally Posted by eboch

Took the console apart and took the shifter out. The only place I could see any "adjustability" was in the attachment to the linkage ... there is a colar/clamp fitting to the rear of the shifter control box (pretty obvious when you look at it, it has a torx screw). This is the main connection between the shifter control box under the shifter and the linkage which runs to the transmission. In my case this fitting was loose and therefore the shifter was not rotating the linkage properly. Loosening this and moving the shifter you can see that different linkage shaft rotations can be acheived. It does not seem to have a lot of play when loose, but it does have some. Adjusting this a few times, I was able to get very smooth gear shifting and perfect "H" centering between 3rd and 4th. The "balance" here seemed to be to get the right amount of linkage rotation to catch 1st & 2nd .... as well as reverse on the other side of the shifter throw. Then check that the shifter also sits nicely between 3rd and 4th without any left-right pushing. I then checked the smoothness of the 2nd to 3rd transition. It took a 2 or 3 adjustment cycles to get it to a good place ... took 5 minutes.

I drove the car last night and again this morning. Shifting beautifully. probably smoother and more precise feeling that it ever did previously.

c4c5 ... are there any other shifter adjustment points to be aware of?

regards
eboch

PS: I see a lot of posts related to difficultied with 1st gear, clunky 2nd-3rd shifting, etc .... I wonder how many of these can be solved with this adjustment (?).

eboch · 08-30-08, 09:15 PM

cheers.

eboch

daking · 11-29-08, 04:44 PM

you need a patient tech to get it lined up right and torqing the bolts is critical

gmjunkie · 11-29-08, 07:34 PM

Quote:

Originally Posted by ggsomers

I had my C6 into the dealer 3 or 4 times to correct shifting into 1st & 2nd problems and they told me that the issue I was having was normal. I then decided to use the internet to see if others were having the same problem. After reading this "Thread" and making a copy and taking it to the dealer I now have perfect shifting into all gears. The dealer had replaced my linkage at about 16000 miles and my shift probems started then. I had a few problems shifting from 1st to 2nd prior to the linkage change. My dealer said they did not have access to this type of info when I showed them these comments. Thanks for the advice because my C6 is better than ever.
HappyC6

Thats Horse Pucky!!They have a Stand Alone Service Information program thats updated daily!!

Besides the MN6 sp Shifters have adjusted the same way since about 1998.

ggsomers · Yesterday, 01:55 PM

Quote:

Originally Posted by gmjunkie

Thats Horse Pucky!!They have a Stand Alone Service Information program thats updated daily!!

Besides the MN6 sp Shifters have adjusted the same way since about 1998.

They have since used the information I gave them to fix another vette. I will relay your info on the Stand Alone Service Information program to them.