1966 4 speed gear shift problems

[fstblk66]

I own a 1966 427/425 that has recently became very difficult when attempting to shift gears, It becomes more difficult as engine temperature rises. Is there anyone that has experienced this problem. Someone please help.

 

[atmmac]

sounds like you may need a new clutch.

 

[allcoupedup]

Can you elaborate? What do you mean by difficult? Is it grinding? Is it physically difficult to move the shifter?


Brian

 

[fstblk66]

The shifter becomes physically difficult to move.

Can you elaborate? What do you mean by difficult? Is it grinding? Is it physically difficult to move the shifter?


Brian

 

[allcoupedup]

Weird.... what kind of gear oil (viscoscity) are you running in your transmission? We're talking Munice here right?


Does it resist when you're pulling out of a gear or trying to go into a gear or both?


Brian

 

[fstblk66]

Muncie rebuilt two years ago, difficult going both in and out of gear

Weird.... what kind of gear oil (viscoscity) are you running in your transmission? We're talking Munice here right?


Does it resist when you're pulling out of a gear or trying to go into a gear or both?


Brian

 

[allcoupedup]

You should check the fluid level - if it is low add fluid. Your transmission may be overheating. If that doesn't help add some 80W90 GL5 gear oil. Many people put super high tech lubricant in these transmissions and report problems. While they may be better protectors and superior technology, these old muncies require a certain amount of friction to operate properly. Best thing to use for street use is plain old GL5 80W90 gear oil.

Brian

 

[MidShark]

I think that I would check the shifter to see if it is lubed and tightened properly.


Rich

 

[61 Silver]

shifter

fstblk66



I had the same type of problem on my 65 and the shifter was out of alignment. There is a key that you insert and then adjust linkage to your shifter. May not be your problem but it is another place to check.



Ray

 

[65365]

I had this same problem on my fresh rebuilt. I was using Red Line synthetic. The rebuilder said no no, synthehetic is to slippery for the syncros to work right. I switched to non synthetic and the problems went away.

 

[Mike McKown]

I own a 1966 427/425 that has recently became very difficult when attempting to shift gears, It becomes more difficult as engine temperature rises. Is there anyone that has experienced this problem. Someone please help.

If you can shift from 1-2, 2-1, 3-4,4-3 your problem is not likely shifter adjusment. If you have problems shifting 2-3 or neutral-R it is likely adjustment.

If you can rule out adjustment, your problem could be with the lubricant.

The fact that you indicate increased temp is a factor makes me lean toward the oil you have in the box.