4 speed shifters

[Rick Daoust]

I have a 1970 Corvette, 350 cubic engine 300 horse power. This is regarding 4 speed shifters, I have to fight to get it into and out of gear and it grinds. I have tried adjusting the shifter linkage but that did not help. Is there something else I can do? I don't want to have to replace the clutch or put in a new shifter.

Thanks

[mark32244]

Re: 4 speed shifters

Hello,

After going through what you have described myself (I have a 70 LS5) The good news is you dont have replace your shifter or clutch. You need to rebuild your transmission. Sounds like you have a engage/dis-engage problem (synchros), which is an internal problem. BTW, since your going to have to pull your tranny, you may as well replace the clutch, its very little extra work at that point. If you need more info please Email me at iguana@neta.com.Maybe some of the other poster can give you a greater insight. But don't be afraid of pulling the tranny and/or the clutch it easy that doing the interior carpet.

Goodluck

[mark32244]

Re: 4 speed shifters

Hello,

After going through what you have described myself (I have a 70 LS5) The good news is you dont have replace your shifter or clutch. You need to rebuild your transmission. Sounds like you have a engage/dis-engage problem (synchros), which is an internal problem. BTW, since your going to have to pull your tranny, you may as well replace the clutch, its very little extra work at that point. If you need more info please Email me at iguana@neta.com.Maybe some of the other poster can give you a greater insight. But don't be afraid of pulling the tranny and/or the clutch it easy that doing the interior carpet.

Goodluck

[Joe L.]

Re: 4 speed shifters

Rick----

You may have an internal transmission problem as Mark suggests. However, more likely in my opinion is that you have a clutch problem. Generally speaking, though, this type of clutch problem is not generated by a worn clutch, but ,rather, by a mis-adjusted clutch. What may be occurring is that the clutch is not completely DISENGAGING when the pedal is fully depressed. Incomplete clutch dis-engagement will cause EXACTLY the problems that you described.

Adjusting the clutch on a C-3 can be very tricky. That's because, very often, when you get the service manual-specified amount of pedal free-play, you will also produce incomplete dis-engagement at full pedal deflection. You have to adjust the clutch so that you have "some" free play AND complete dis-engagement with the pedal fully depressed.

If clutch adjustment doesn't solve your problem, you'll probably have to go into the transmission.

[Joe L.]

Re: 4 speed shifters

Rick----

You may have an internal transmission problem as Mark suggests. However, more likely in my opinion is that you have a clutch problem. Generally speaking, though, this type of clutch problem is not generated by a worn clutch, but ,rather, by a mis-adjusted clutch. What may be occurring is that the clutch is not completely DISENGAGING when the pedal is fully depressed. Incomplete clutch dis-engagement will cause EXACTLY the problems that you described.

Adjusting the clutch on a C-3 can be very tricky. That's because, very often, when you get the service manual-specified amount of pedal free-play, you will also produce incomplete dis-engagement at full pedal deflection. You have to adjust the clutch so that you have "some" free play AND complete dis-engagement with the pedal fully depressed.

If clutch adjustment doesn't solve your problem, you'll probably have to go into the transmission.

[Jack H.]

Re: 4 speed shifters

Just to make sure we're all on the same vine, please confirm the symptoms you're seeing happen in all gears (Muncie WILL grind into reverse if you don't first shift to 1st to achieve synchro). Plus, if linkage has been set to short throw by prior owner, getting through the gates will be modestly harder ('sticky') but shouldn't result in gear mesh/grind....

[Jack H.]

Re: 4 speed shifters

Just to make sure we're all on the same vine, please confirm the symptoms you're seeing happen in all gears (Muncie WILL grind into reverse if you don't first shift to 1st to achieve synchro). Plus, if linkage has been set to short throw by prior owner, getting through the gates will be modestly harder ('sticky') but shouldn't result in gear mesh/grind....

[Roberto L.]

Re: 4 speed shifters

Jack, by short throw setting you mean the upper hole in the linkage, is this correct? You trade long movement vs effort. Understand that there is a similar adjusting in the shifter. Thanks Roberto NCRS #30019 RMC

[Roberto L.]

Re: 4 speed shifters

Jack, by short throw setting you mean the upper hole in the linkage, is this correct? You trade long movement vs effort. Understand that there is a similar adjusting in the shifter. Thanks Roberto NCRS #30019 RMC

[Wayne M.]

Re: 4 speed shifters

Roberto --- It's just the opposite; rods in lower holes (ie. those closest to the shifter fork shaft, where it goes into the side cover). This shortens the rod travel (and shifter movement) for the same result on the shifter fork. Changing from short throw to standard (or vice-versa) should also call for re-adjustment of the gearshift control adjustment (with locating pin) as described in the AIM.

P.S. thanks for the link to www.yl-gazette.com for previous owner searches. There's not much action, but it's a long shot anyway. ------ Wayne

[Wayne M.]

Re: 4 speed shifters

Roberto --- It's just the opposite; rods in lower holes (ie. those closest to the shifter fork shaft, where it goes into the side cover). This shortens the rod travel (and shifter movement) for the same result on the shifter fork. Changing from short throw to standard (or vice-versa) should also call for re-adjustment of the gearshift control adjustment (with locating pin) as described in the AIM.

P.S. thanks for the link to www.yl-gazette.com for previous owner searches. There's not much action, but it's a long shot anyway. ------ Wayne

[John]

Re: 4 speed shifters

My four speed wasn't as bad as your seems to be, but it was hard getting it into gear. My car is 20 years old and I don't think the gear lube was ever changed. I removed the drain plug, drained the lube and sprayed about a quart of kerosene in through the fill hole. Put in new lube and now it shifts like new. Don't know if this will help yours, but it will be worth a try. Good luck!

[John]

Re: 4 speed shifters

My four speed wasn't as bad as your seems to be, but it was hard getting it into gear. My car is 20 years old and I don't think the gear lube was ever changed. I removed the drain plug, drained the lube and sprayed about a quart of kerosene in through the fill hole. Put in new lube and now it shifts like new. Don't know if this will help yours, but it will be worth a try. Good luck!