'63 Muncie shift linkage binding

[Glen S.]

I am having an issue with my '63 Muncie sometimes popping out of gear on deceleration. The transmission has been rebuilt recently and I doubt there is an internal problem although anything is possible. The shifter adjustment seems to be correct.

I have noticed that the 3-4 and 1-2 arms are binding against each other when in third perhaps causing the problem. I know from experience that the shift linkage is tempered (to the point of being brittle) and that trying to bend the linkage only causes them to snap. Is it feasible to try and alter the offset on the transmission arm to relive some of the binding? Any thoughts?

[Bob R.]

Re: '63 Muncie shift linkage binding

Have you checked the AIM or the shop manual to be sure you have the rods installed correctly. I believe the correct installation of the 3 and 4 rods cross each other.

[Glen S.]

Re: '63 Muncie shift linkage binding

Yes, I have checked and confirmed that they are installed correctly. - - Thanks.

[Tracy C.]

Re: '63 Muncie shift linkage binding

Yes, I have checked and confirmed that they are installed correctly. - - Thanks.

I'll bet you have the wrong rods or wrong levers on the tranny. Mine aren't even close to touching.

63 Muncie Side shot and Top Shot while in Neutral


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[Gene M.]

Re: '63 Muncie shift linkage binding

Popping out of gear on deceleration is generally internal transmission issue not the shift linkage. As stated nothing should be even close to touching with the linkage. You say it is all installed correctly, that makes me suggest bent or wrong parts.

[Joe R.]

Re: '63 Muncie shift linkage binding

Glen,

Refer to ST 21 1963 Corvette Shop Manual and look on page 7-15. Where the rods connect to the bottom of the shifter you or someone has probably put the rods in the wrong direction causing binding where they cross. Check that!
But I do agree with the above poster the problem is usually the synchro assembly slider or the gear itself worn out. Some companies make dovetail sliders to help lock in worn gears. Good luck!

JR

[Timothy B.]

Re: '63 Muncie shift linkage binding

In the Noland Adams book there are good pics of the correct 63 shifter rods and parts. If you are sure they are correct double check the shifter adjustment per the aim.

Who overhauled the transmission.

[Glen S.]

Re: '63 Muncie shift linkage binding

Thanks for all the input on this issue! The rod clearance is only an issue when in 3rd gear. I have personal knowledge of 3 different '63 4-speed cars that have had problems popping out of 3rd gear (two Borg Warner, 1 Muncie). Looking forward at the '64 AIM apparently the Muncie linkage was redesigned when they changed the shifter eliminating the crossing of the shift linkage. I flattened the 3-4 shift arm slightly to reduce the contact and shortened the 3-4 linkage 1/2 turn. I just got back from road testing the changes and it is more consistently coming out of gear on deceleration at about 30 mph.

I want to rule out any external issues before pulling the transmission. The transmission was rebuilt by Darrell at 4 Speeds by Darrell (JT Piper) and most recently gone through by Daniel Espino. BTW, it passed PV last year.

In Figure 21 of the Shop Manual, it appears that the offset on the shift arms is different that what is shown in the 63 AIM. In the AIM the 3-4 arm has the larger offset, the 1-2 arm having the smaller offset. In Figure 21, it appears the other way around.

[Glen S.]

Re: '63 Muncie shift linkage binding

Update: The 3-4 shift arm had an offset of about 1.1". I flattened it to reduce the offset to about 0.9" (outside to outside). This eliminated the linkage interference when in 3rd gear.

I increased how far the transmission was going into 3rd gear by shortening the 3-4 shift linkage by 1-1/2 turns total from the initial adjustment. I just got back from about a 10 mile run and it did not pop out of 3rd on deceleration. I am not claiming the issue as resolved until I put more miles on the car but it appears that this has resolved the issue.

My primary purpose in posting this is to encourage others to rule out external (shifter, linkage, etc.) issues before pulling the transmission for a rebuild. Lots of times the problem is internal to the transmission but not always.

Thanks for all the feedback! - - Glen

[Timothy B.]

Re: '63 Muncie shift linkage binding

Glen,

Is the shifter adjusted correctly? This may cause the 3-4 rod to not move the lever far enough to click it into gear. Going from memory there should be alignment holes in the shifter to slip a tool inside which aligns the shifter and linkage. The alignment is made by adjusting the clevis making the rods longer or shorter.

[Glen S.]

Re: '63 Muncie shift linkage binding

There are slots on a '63 shifter that are for the purpose of aligning the linkage. I made up a block to fit the slots. Having needed to adjust the shifter a few times over the last 32 years that I have owned the car, I have found out that the method gets you close but is not precise.

A little fine tuning is needed to get things perfect. For example, I have shortened the 3-4 linkage by 1-1/2 turns and have noticed no change in the 1-2 to 3-4 gate feel. There is a lot of slack in these old shifters.