BlueTwoToneCorvette

Just got my car back together. Driving while data logging I noticed that when I lift off the throttle in 3rd gear, the shifter vibrates violently. Acceleration is fine, no vibration. Otherwise, 4+3 shifts great, smooth, no grinding.

OD seems to work normally, but I am having an intermittent electrical issue where the OD light fails to come on and no OD. I have the 1st/2nd gear switch's connector shorted so I can control OD with the console button. I cleaned/checked that short, it should be good. I need to check the two OD connectors, they seemed fine when I plugged them in.

Is there an adjustment or something I can check on the shifter/transmission for the vibration?
Thanks

BlueTwoToneCorvette

Some background. When I put the transmission back in I used a gauge tool in the side of the shifter to align neutral so that I could adjust the linkages and connect them to the transmission.

I am thinking that I didn't get the 3rd/4th linkage adjustment correct so that it's not going all the way into gear in 3rd. I'll try to adjust that linkage so that it goes further when shifting to third.

corvetteracer72

I was about to ask you about gear linkages. I might get into the same issue now that I've changed the clutch. Haven't had the chance to drive my car after clutch change but i have noticed that when I put it into 3rd the shift boot leather somehow doesn't let the shift lever to go all the way in .

BlueTwoToneCorvette

Unless you changed the setting on the threaded ends of the shift linkage then you will probably be ok.

If your shift gates don't seem to match up right in neutral then you may want to do what I did and lock the shifter into neutral using the gauge tool from the side and then adjust the linkage ends to fit back on the transmission.

I checked the 3rd/4th linkage movement stops against the movement of the lever on the transmission and it has more than enough travel to fully engage the transmission lever. So I don't think the problem is that the shift linkage is not moving the transmission lever fully.

I have googled gear vibration on deceleration, and surprisingly found almost nothing.

BlueTwoToneCorvette

I think I may have found why I am getting the vibration in 3rd. When I move the 3rd/4th lever on the transmission to 4th it locks into the detent, and moves no further. When I move it to 3rd, it locks into the detent, but I can keep pushing it a little further. It rocks back into the detent when I release it. I think that on throttle lift the 3rd gear is bouncing a little more "into" 3rd and then back into the detent, and this being magnified into my stick.

I'll have to remove the side cover and examine the 3/4 gear lever mechanism. It is also leaking oil badly from that lever. Has anyone disassembled the lever mechanism? Is the detent ball/spring the only stop in there, or does something else limit travel? Could just be worn from slamming 2nd to 3rd?

coupeguy2001

I would look at your u joints.
what you described is typical of one about to give up.
jack the car, climb under and rotate the driveshaft back and forth.
it should not have any play.
hold the drive shaft securely while someone rocks the wheels forward and back, you might have to change 6 u joints like i did