901 Transmission shifting issues on 4th/5th plane

[redrobin911]

I was racing over the weekend and towards the end of each race the transmission wouldn't shift into the 4th/5th plane - it was fine for the first 7-8 minutes then wouldn't shift, before the second race while parked up made some small adjustments to the gear linkage as it seemed "tight" trying to select 4th/5th - the adjustment made it possibly easier to select but then the same thing happened in race two. I took the car out today just for a quick drive and of course it's perfect but then I'm not pushing it and no doubt the problem will come back at the next race meeting. There is obviously a selector issue that looks like it might be heat related - but I'm no expert. If anyone has had this issue before or has and idea what it might be it would be useful to know prior to stripping it so that we have an idea what we're looking for.

[Mike911scrs]

HI redrobin911

it looks like the selectors need to be set up correctly, you do have the tooling for this?

regards mike

[redrobin911]

HI redrobin911

it looks like the selectors need to be set up correctly, you do have the tooling for this?

regards mike

HI Mike - no I don't. My mechanic mentioned a jig to hold the selectors and rods in place but he normally sets them up with "adequate" clearance - he's built many over the years. He's going to open up the tranny on over the next few days and check visually for anything out of place but some spec or correct spacing/tolerance would be a huge help - obviously the internal shift lever isn't aligning correctly with the indent on the 4th/5th elector rod. I assume the tooling isn't cheap or easy to get - I do think I might consider buying as a, can't afford non selection issues reoccurring when racing and b, have another 2 or 3 transmission to build in the next year so don't want to have too many similar problems.

Can you offer any help?

thx in advance