transmission scratch

[Guest erector]

My 40 sport coupe scratches when I go into 3rd. Is this normal? I don't think it used to do this. I have been restoring it and have only driven it a few times since I bought it a couple of years ago. I can double clutch it so it won't do it but I don't think this should be necessary.

[The Old Guy]

The usual cause of this problem is worn synchronizers. You can either replace the synchronizers or shift it a little slower. My 40 has the same problem, but I'm not sure you can even find NOS synchronizers , so I just live with it.

[jscheib]

I say, when in doubt - double clutch. A little strain on the muscles both left foot and right hand for the shifter is not worth more damage to the gear box.

John

[Guest ZondaC12]

^^^ Great Idea. my car doesnt make any noise but she doesnt like 2nd, i guess id say. it just wont go in, unless you try multiple times and use extra force. i did that the first few times i drove the thing, and then tried double clutching out of curiosity. <img src="http://forums.aaca.org/images/graemlins/shocked.gif" alt="" /> like a HOT knife through butter. so now i do it into 2nd AND 3rd though, 3rd is actually great without it. its become a habit and really youre not looking for quick split second shifts. and with practice i actually got good at it and it doesnt add much to my shift time. originally i was really excited, i thought it would be non-synchro, manual choke, all this special stuff id have to do just to get it going. then i read the owner's manual and found out i just needed to be able to drive stick. that easy to use (boo hoo so terrible right? <img src="http://forums.aaca.org/images/graemlins/laugh.gif" alt="" />) so i like "needing" to double-clutch it.

[Patrick W. Brooks]

Hello All: My problems with sychronizers have involved primarily noise

(scratch) going into second and jumping out of first.

This does not mean it could not

scratch when going into third as well, just not my experience. However,

when reassembling drivetrains after restoration I have encountered this problem on

several occasions and found that adjusting the transmission control levers is the

needed touch. If you have a chassis parts book look for group 4 and the

schematic on transmission control levers to see a picture of the parts

I am going to refer to. These control levers adjust the shaft in the

steering column in relationship to the transmission linkage which fastens to the

components found at the steering column. There are three pieces which require

movement to do the adjusting. First, a lever (marked AU in the schematic)

which has a curved slot in it. Second, an adjusting lever (marked AT

in the schematic). The third important piece is the nut and bolt which

passes through both AT and AU and adjusts the swing of the linkage which

engages the gears in the transmission. I suspect that third gear is simply

not being engaged completely and when you release the clutch it completes

going into gear by itself and makes this scratching sound. I have heard it

before and this adjustment has always worked for me. I think you need to loosen

the nut and bolt and move the adjustment lever toward the engine a bit and

then tighten the nut and bolt again. You can try several positions to determine

what might work best. Try this and post your results. Good luck, Patrick W.

Brooks

[Guest Straight eight]

'Way back in the 50's my 47 Super would scratch when shifting, and I too double clutched it. One day I dropped into the Buick Dealer and he suggested changing the transmission lube. Just a straight 90 weight with non of those slipery additives. Solved my problem then, and recently on my 47 56C. I like Pat's suggestion too. May give it a try. Thanks Pat! <img src="http://forums.aaca.org/images/graemlins/smile.gif" alt="" />