gearchange problem on 356SC

[Peter Roberts]

I have not used the car much since a complete resto but have developed a strange gearshift problem. Car has been out about half a dozen times with everything working fine. On a test drive this week the car suddenly refused to go into 3rd and 4th gear so had to drive it home in second. Checked all the connections on the gearshift rod for tightness and everything seems ok. With the engine on stop i can select all gears. With car stationary and the engine running i can select all gears as normal. Take it for a drive and it will not go into 3rd and 4th. It feels as if the selector is not lining up with the fork as the stick is just solid.
I did not strip the box during restoration as the gearbox was working perfectly with all syncro's giving a smooth change. The engine and gearbox mounts are in great condition so the lump is not moving around when being driven. I have taken out the gear change rod and checked the shifter guide ring. Its 21mm bore does not appear worn and the 20mm shaft also has no wear. There is a little play in the shift coupler at the gearbox end but nothing to believe it is causing the problem. One thing i did change was the gearstick guide in the shifter mechanism which stops you selecting reverse so the stick is not going over too far when going into 3rd. Even though they look ok i am ordering a new shifter guide ring and ball socket before putting the rod back in but do not think it will make any difference.
Has anyone encountered a similar problem or have any suggestions?

[Mike Smith]

Although you checked and it was all tight, it only takes a slight movement, somewhere in the linkage to produce the sort of symptons you describe

When you reassemble it all, I am sure you will sort it out

However, with all that said, what about the Bushes in the Universal Joint at the Transmission end ?

[Peter Roberts]

It is going up on the ramps today to check out the play i can feel at the gearbox end. Do not know where that is at the moment. Like to know if the bushes are available separately for the universal joint as it looks like an expensive assembly

[Mike Smith]

Available separately - £7-00 each
Assuming that they have broken up you will need 2

www.prs356.com
Put the word `Gear` into search
Page 5
3rd Column 1/2 way down


The hole in the bush is NOT round, it is an oval to allow the Detent Pin to settle into the slot in the Selector Rod

Take care pushing out the Pin in the Universal Joint - it is often tight and it is not unusal for people to break the Casting

[Peter Roberts]

Thanks for your help I will be on the phone to PRS tomorrow to order.
One other query. The reverse lock on the gearshift does not work. There is nothing on the rod for it to locate into but there are two cross drilled holes. Should something be bolted onto the rod?

[Mike Smith]

Peter,

Please use the website to order (believe me - it does work) we are still short staffed staffed due to Covid and cannot handle the volume of telephone calls

Gear Lock - Yes you need the piece that the Key part locks into
It is not availalble as a new part but we may be able to help you with a good Used One - although they are probably paired up with all the locks that we have

Do you have the Key ???

[Peter Roberts]

Yes I have key. After much searching and forum visits I sent the lock to a locksmith in Kent. Porsche gave me the key code but it was incorrect. This guy sussed out they had put in an extra digit so cut a key to what he guessed it should be ad hey presto I had a key for £12.00.
I will go on line now and order the parts

[Mike Smith]

That was a Deal

That Lock is the most difficult lock on the car, to take apart, to make a key

[Peter Roberts]

Good news. Bought the gear rod and coupling bushes from PRS and after a lot of fiddling got the gearchange set up correctly and i now have all the gears.
During the work i noticed that the reverse lock collar on the gear rod was missing which explained why i could not lock it in reverse.
PRS supplied a collar and now i have a working lock.
However just by chance i noticed the reverse light was on when i operated the lock even though the ignition was off. That suggests it is nor wired through the ignition system but on a permanent live feed. Surely this cannot be right as you cannot leave the car locked in reverse as it will flatten the battery.
Can anyone set me straight on this as a previous owner may have modified the supply for some reason.

[BD55]

Peter, I believe the feed for reverse switch comes from fuse number 1, which is powered from ignition switch, you may have the wires on the wrong connectors on the switch, or feed wire is on fuse 2 or 3 which I think are permanent live?? Power for fuse 1 comes term 15 on ignition switch.... Do you have wiring diagram?
Simon

[Peter Roberts]

Yes i have now got a wiring diagram as i have found my long lost manual. It shows the wire from the switch going to a connector block. Can you advise where i can find this connector block? Also wiring diagram is not very clear on cable colours. What cable colour should i be tracing.

[BD55]

I think it's brown/grey. The connector 'block' is under the dash. If you let me have your email address via Pm I can send you a link to colour diagram.
Simon