67 shifter adjustment problems
I decided after driving a buddy's 66 that my shifter on the 67 wasn't quite right. It has been hard to shift every since I bought it but I just figured that was the way a 40 year old should work. I emailed John Hinckley and he quickly forwarded his Muncie shifter rebuild article he had written for the January 2008 issue of Corvette Enthusiast, THANK YOU JOHN!! It helped tremendously while working on my shifter. Now that the shifter is back in the car and I am in the process of adjusting the linkage I have a couple more questions. First one has to do with which hole to use for the short throw shift. When I bought the car in 2006 the shifter was adjusted for the close ratio shifting (short throw). I completely forgot to check when I took the shifting rods off to make sure I attached the rods to the correct hole but I believe for the short throw shift you would use the lower holes (ones closest to shaft) on the shift arm is that correct? Second question has to do with linkage adjustment procedure. Should you be able to slide the gauge adjustment "tool" thru all 4 plates (1-2, 3-4, interlocking, reverse)? I have made the shim gauge (1/8" x 41/64" by 2 inches long) out of a piece of oak trim. This is the size of gauge it states you need for the 67 shifter. I can only get the gauge thru the 1-2 and 3-4 plates. If it needs to go thru all 4 pieces is there a trick in doing so? I adjusted the 1-2 and 3-4 linkage since I could get the gauge in and locked in place. They seem to be pretty close. However the reverse is giving me fits. Any secrets? Thanks in advance for any and all help. John, thank you again for forwarding me your article. Take care, Shooter
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Re: 67 shifter adjustment problems
Your interpretation of the correct holes for "short throw" is correct. Tool should lock all levers in place for proper adjustment.Bill Clupper #618 -
Re: 67 shifter adjustment problems
Thanks Bill. If I hadn't repainted the arms I probably would have been able to see that the bottom holes had some scratches and wear around them.
On the gauge question I know the shifter tower is suppose to be in the neutral position to insert the gauge but it seems the tab on the end of the shifter is blocking the gauge from going thru the interlock and reverse. I didn't know if the tab should be moved someway to get the gauge around it. Thanks again.Comment
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Re: 67 shifter adjustment problems
OK, check the A3 sheet on your AIM for complete instructions on adjustment. The gauge should go thru all plates unless one is out of adjustment. An alternate method is shown in the '64-65 aim using a pin and the notch in the lower side of the housing. Either method should work. Sorry to be so late, Been working on taking 20 years of various sealers/topcoats off my deck so I can start over with a finish coat. About as much fun as stripping a Corvette!Bill Clupper #618Comment
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Re: 67 shifter adjustment problems
Dang Bill you do have some work cut out for you..............stripping wood is a young man's game. Thanks for your reply, I appreciate it. I was finally able to getthe gauge thru all f pieces. My problem was I made the gauge out of oak trim and it was too thick. I Googled "Muncie Shifter Adjustment" and one site that came up was the Chevelle forum. One of the guys on there had cut a putty knife down and used it as the gauge. I cut one of my old ones down to the 41/64" about an inch or so long, bent it cut half the handle off and it worked. The thickness and stiffness of the putty knife worked super and I was able to hold it in place without any problems. I got the shifter adjusted where it seems to be pretty close but it still shifts hard going into most of the forward gears. I don't know if a little clutch adjustment would help or not. There is no grinding or clutch slipping when I take off so I don't believe that is the problem but I might still check. I had changed the fluid in the transmission when I got the car but I may try that again and make sure it is clean. Any ideas or suggestions? I did grease the shifter up pretty good so I don't think it is hanging up because of dryness.Comment
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Re: 67 shifter adjustment problems
Hello Henry;
The shift linkage will require more force in the "short pattern" adjustment. My experience is the General sent 4 speed cars in the "long pattern".
Try shifting with the engine running and without the engine running. Is there a difference? If not, the clutch isn't the difficulty.
Hope these comments help.
RayAnd when you get the choice to sit it out or dance
I hope you dance
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Re: 67 shifter adjustment problems
I'm with Ray, the shifter has almost NOTHING to do with hard shifting in the forward gears unless it is so corroded as to need a complete disassembly/overhaul. A clutch adjustment would be my first stop for an upshift problem, either that or badly worn brass clutches on the synchros.Bill Clupper #618Comment
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Re: 67 shifter adjustment problems
Ray and Bill,
Thank you for the responses. I will be headed over to the shop later and will try the shifting both with and without engine running to see if there is a difference. I didn't really think about the difference in the short and long pattern shifting but it stands to reason the further away from the pivot point the less force you need to move something.Comment
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Re: 67 shifter adjustment problems
Henry, I've run my '65 on short throw since I got it including drag racing a few times (full powershifting) and never had any "effort" issues.Bill Clupper #618Comment
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Re: 67 shifter adjustment problems
I just got back from the shop after trying the shifting with and without the car running and from what I could tell there is no difference. Went ahead and drained the transmission. When I got the gear lube out to refill it I noticed what I had was GL5 lube. That was the type I put in it back in 2006 when I bought the car originally and changed it. If I am not mistaken shouldn't it be GL4 80 w90 or GL4 75-w90? Could the GL5 have added to the shifting problem or am I way off base? Thanks again guys.Comment
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Re: 67 shifter adjustment problems
Hello Henry;
GL5 lubricants should not be used in gear boxes with brass / bronze type metals.(synchronizers).
Whether this is creating the difficult shifting will only be known after changing the lube to original specifications.
Maybe an engineer will chime in here to better explain.
Hope this information helps.
RayAnd when you get the choice to sit it out or dance
I hope you dance
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Re: 67 shifter adjustment problems
Thanks Ray. I'll be picking up some GL4 this week and trying it out. Forgot to mention but the transmission had been changed out before I bought the car. The transmission is actually dated as built Aug 1970 (P0M11B). Don't know if they still used brass metals in the 1970 transmissions or not.Comment
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Re: 67 shifter adjustment problems
Brass was used in all muncies as the clutch material in the synchro assy.Bill Clupper #618Comment
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Re: 67 shifter adjustment problems
Thanks Bill. Calling around to some of the local auto parts (AutoZone, O'Reilley, Advance,) none offer just a GL4. There are a couple brands, I think Lucas was one, that said they have one that is GL4 and GL5. HUH
Maybe they put a pint of GL4 on the bottom and a pint of GL5 in the top of each quart. 
I'll check at Chevrolet dealer or NAPA tomorrow as they are closed today for Memorial Day. We're heading to an Honored Flight service later today and thought I would pick up the gear lube while we were out. Special thanks to all our veterans today and every day!!
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Re: 67 shifter adjustment problems
Hello Henry;
The "Honor Flights" are the well deserved by the "greatest generation" and extremely moving.
As a gear GL4/80w90 lubricant I personally use synthetic GM Part
12378261.
Think that's the current number.
Ray
And when you get the choice to sit it out or dance
I hope you dance
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