Manual trans Linkage Adjustment

[rnd5553]

Hi - looking for direction on how best to adjust the shift linage on my "66 LM 4 speed coupe.

The issue stems from when shifting into 4th gear pops out ( or won't go into 4th) immediately most of the time. This has just started after a recent engine swap where we left the trans/diff in the car. Yes, the linkage was disconnected during this engine change over.

The shop manual's Fig 7A-2 notes dimensions of .50 max and .40 max taken from the front of the seat, but what is this dimension in inches?

I would think that since it's popping out of gear or wont go into gear immediately, that the shift rod needs to be length slightly when trans is in the 4th gear position.

Comments welcomed. Thanks.

[Danny Joe]

If the shift coupler clamp was loosened, it may not be adjusted correctly.

Put the transmission in neutral, loosen the clamp on the shift coupler and position the shifter in the center of the pattern. Then tighten the clamp.

[terribleted]

Does it also have issues in 2nd? Shortening or lengthening the shift tube will effect both 2nd and 4th. Is your hand or the shift ball against the seat in 2 and 4? Nothing ventured nothing gained you could try an adjustment to see what happens, but you need to go shorter not longer. IF you look at how the shifter ball under the shifter moves when you move the lever it becomes clear. When you pull the shifter back (2nd and 4th) the ball under the floor moves forward pulling the shift tube forward. So to get more movement forward you would need to shorten the rod, and the ball will move closer to the seat. If your shifter is not hitting the seat and is pulling the transmission shift shaft out to its stop then fore and aft adjustment will likely have no effect. Does 3rd gear engage cleanly? There is often a little side slop in the shift coupler that can effect 3 and 4 or reverse not selecting happily. When this happens a little twist of the coupler can be made to find a happy spot in the middle. For a 3,4 sideways shift issue rotating the coupler CCW will make the twist more toward 3 and 4.

Could very well be an internal trans issue...synchronizer worn perhaps.

[rnd5553]

no only issue is going into 4th - new coupler and trans was completely rebuilt and has 600 miles no issues like this till the engine swap in April and afterwards the 4th gear issue raised its head.

[terribleted]

Try tinkering coupler adjustment a little, I would be trying to twist it a little sideways perhaps as making the rod longer or shorter should make zero difference unless the shifter lever is physically running into seat not allowing it to be pulled fully back. You would likely want the coupler to twist a little more clockwise if possible (more engagement). The current adjustment could be over engaging the shift but this is less likely. There is a notch in to coupler and an index tab in the shift tube that keeps there from being much twisting adjustment. but, I have had a couple cars that needed to be twisted fully one way or the other within the limited slop to shift nicely. Tis possible that your 4th gear is particularly finicky about what adjustment it will accept. If reverse goes away after twisting the coupler then you went to far for reverse to be happy. I had one car that was very finicky about adjusting the spot where both reverse and 3/4 shifts would work nicely.