Sometimes shifting to second...

[calbrat]

after a hard accleration in first, my shifter grinds until it engages in gear. Yes I have the clutch down...

My clutch appeared fine after rebuilding the engine. Everything is real tight back there now, including the rear suspension, motor mounts, etc. But now this problem. Could it be as simple as replacing the clutch cable or is soemthing else (more expensive)
happening. Every other gear is fine and shifts smooth.

[red-beard]

It sounds like to me that the 2nd gear synchro is going. Double clutch second until you are ready to have the tranny work done. This will prevent further damage and reduce the overall(haul) costs.

James

[AaronM]

Originally posted by red-beard
It sounds like to me that the 2nd gear synchro is going. Double clutch second until you are ready to have the tranny work done. This will prevent further damage and reduce the overall(haul) costs.

James

Bingo. Synchro. If I shift very slowly into second, I'm fine, but anyting remotely resembling a quick shift causes me to "beat the synchro" and make bad noises. I've been double-clutching both up and down for 2nd and I don't engage first unless I'm stopped. The synchros in these older Porsches aren't that great.

Aaron

[BillySpaceman]

I sometimes get this too. Is it possible the bushings just might need to be replaced? If I am careful when I shift I don't get the grind, but if I am not thinking the old grind till you find sound shows up.

[BenI]

Check out my memorial day project...




I hope they help. I was trying to give the bushings a solid mount to the chassis and a tighter fit to the rod. I won't know how they work for sometime though as I'm in the middle of the engine rebuild...

Ben

[AaronM]

Originally posted by BillySpaceman
I sometimes get this too. Is it possible the bushings just might need to be replaced? If I am careful when I shift I don't get the grind, but if I am not thinking the old grind till you find sound shows up.

Grinding is not a function of the bushings. Unless they are absolutely terrible and do not permit full engagement of the gear, grinding isn't related to the bushings. Bad bushings will just give your shifter a vague feel and may cause you to miss shifts. Also, bad bushings would show up for all gears, not just the low gears. 1st and 2nd synchros are usually the most beaten up, especially with the notoriously fragile synchro rings on these old Porsches.

Aaron

[Eric Fry]

Hey Ben, I was under mine the other day and going thru the same mental exercise. A tighter fit at the trans end would be very nice. If you would like me to try them out for you, just let me know. If not, well, let us know how they work. I'm thinking of visiting my machinist soon.
Eric

[BenI]

Yea, I think they will have to help. I'd changed by '70 over to side shift and the firewall bushing was very loose-my linkage was flopping all around. I think these bushings may need some more work after I test fit them-I went for a pretty close fit between the rod and bushing and may find that it binds. I was surprised at the loose fit the new plastic Porsche bushings had-not really sure why they designed them that way. I did use oil impregnated bronze so I hope that will help keep the action smooth...

Ben

[Eric Fry]

Another thought Ben. while you have the shft linkage out be sure to look at the point at the rear of the rod, where the tubing turns to solid rod. If you have not already done so, continue the little half a**ed factory weld to the rest of the joint. Ask me how I know.
Eric

[red-beard]

Ben: The firewall bushing for the sideshift and the tailshift are different. There is a special bushing used in the early cars when they are converted for the sideshift.

< Warning - shameless plug>. I know our host carries these

The synchro's in the cars are 30 years old. They need to be replaced. And as soon as you hear grinding, you need to replace them or you will damage far more expensive components (dogteeth and sliders).