Clunky 2-3 shift

darth_linux

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On my ‘66 Newport my 1-2 upshift is smooth and silent, but my 2-3 shift is loud and clunky. Inspecting the u-joints found no faults. Is this “a thing” or is something else amiss that I don’t know about?

Thanks!
 
What if you lock out D and then manually shift it up? Still clunky? Is it slamming into third? What do you mean by loud? Like a bang? Metal on metal? No, the 2-3 shift should be smooth and seamless more or less.
 
At what speed(s) and throttle settings is this happening? 2-3 is usually smoother than the 1-2 shift as there is less torque multiplication difference. If this happens on a closed-throttle 2-3 upshift, you might check the rear axle for the source of the noise.

On our '66 Newport 383 2bbl, we discovered that at about 25mph in 3rd, that a quick throttle pedal movement, as in cruise . . . no throttle . . . then throttle to maintain speed (about 30mph, or perhaps a bit higher), a "clunk" could be heard from the rear end. The old-line Chrysler service manager at the local dealer said that was normal and not to worry about it. This was when the car had about 40K miles on it or so. No problems ever, from that issue.

On our car, the front u-joint was the first to cause issues. I had first noticed a quiver when cruising at 70mph. As it was not major, just something to notice as my arm was on the top of the front seat back during long highway runs at 70mph, it was not a big deal. Then, a lower-frequency quiver started to happen on brisk acceleration from stop, plus a similar speed-related squeaking. I took the wheel covers off to check for the squeak, to no avail.

So I took it to the local Chrysler dealer (away at college). The service writer drove it a short distance and came back with the diagnosis "front u-joint". It had not been that long since we checked them on the rack at an oil change, BUT that fixed it. The front joint is where most of the up and down movement usually happens, plus driving torque (which can wear the related front yoke bushing and seal), it seems. The rear joint is still the OEM production unit.

Just some experiences,
CBODY67
 
Yes give us some more info. Is it just a sound or do you feel it? Can you tell is the engine RPM jumping up during the shift between 2 and 3? It could be a number of different things. Could be worn clutch or possibly the 2nd gear band out of adjustment. Has the trans been worked on recently?
 
In the 2-3 shift, there is a period of overlap where basically drive and second are both engaged. Some shift kits try to eliminate most of this by making drive engage a little slower, giving second more time to release.

That said.... Let's ask this question.... Is the throttle linkage to the trans working and adjusted correctly? Some refer to this (incorrectly) as the kickdown linkage. That controls line pressure and could be the problem.
 
After removing the 1972 truck specification Carter BBD, and replacing it with a period correct Stromberg WWC, I made a quick adjustment to the kickdown linkage, and I think I had the rod too long, which was supplying too much line pressure.

The transmission was really wanting to stay in second gear until I was completely off the throttle and coasting, and then it would clunk into third. I dug out the FSM and readjusted the kickdown linkage to factory specifications. Pictures below, tell me what you think. I’m gonna take it for a drive later today and see if the issue is alleviated. Thanks for everyone’s tips and suggestions.

Rod length adjusted and pulled forward to just touch carburetor lever.
F6551F6A-031D-44C5-BBD0-54C5B0700267.jpeg


Tension released on rod.
DA7C701A-FFF9-4834-A89A-D73312B40BB9.jpeg


Rod lengthened by two turns.
9A49F675-CDA9-4A11-8547-97DFC4421A6D.jpeg


Return spring tension applied
91E3830C-3BE6-4A55-A301-287FF9452DEC.jpeg
 
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In the 2-3 shift, there is a period of overlap where basically drive and second are both engaged. Some shift kits try to eliminate most of this by making drive engage a little slower, giving second more time to release.

That said.... Let's ask this question.... Is the throttle linkage to the trans working and adjusted correctly? Some refer to this (incorrectly) as the kickdown linkage. That controls line pressure and could be the problem.
This was indeed the problem. After replacing carburetors, I did a quick and dirty adjustment of the kickdown linkage, or whatever it's called, and I wanted to add a bit of "pre-load" to it as others have recommended. Apparently I added too much. After resetting everything and adjusting to factory specs, the shift from 2 to 3 is smooth and silent. It takes a little more "foot" to get it to kick down than before, but it's probably now the correct amount.

Thanks Big John, Cbody67 and others! Shifting is smooth and perfect again.
 
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