Gear change sticking when warm

[haty167]

Hi hoping someone can shed some light on this.
The gear change on my 5 speed 1990 1.6td is lovely and smooth (as much as they can be) when driving around town.
However, once I've driven on the motorway, or on any long stretch of road for a while, the gears become very hard to select. The gear lever seems stuck in gear and the gates between gears seem to disappear
I've resorted to doubling the clutch, which helps a bit.
Once it's rested it's all fine again.
Gear box oil was changed late last year.
All answers that I've trawled through talk about difficulties when cold!
Any ideas?
Ta

[silverbullet]

Do you know if it has had a re-con transmission by someone other than Aidan Talbot?
I had a 5-speed that had been repaired under the previous owner but the diff had been set up too tight, so when hot the gearchange became very notchy.
Aidan diagnosed it and did the rework.

[haty167]

No I don't have any history on the transmission.

[CJH]

Mine does the same. Two things that improved it significantly were:

1) a new clutch slave cylinder. The old one was probably ok, but the clutch fluid was black like coca cola, and I suspect may have become a bit compressible at temperature, leading to a dragging clutch - that's just a guess mind.

2) Removing the gear selector box above the spare wheel, wire brushing it clean and regreasing it.

It still does it a bit, but only after a long run at speed on the motorway - after a few changes on slower roads it goes back to normal. Until Silverbullet's comment just now I had suspected that the spigot bearing was beginning to wear, and was perhaps dragging a bit when the box got hot, but now I guess it might be a tight diff. That would perhaps explain why it seems to be a bit temperature-related (doesn't do it so much in the winter), and why it only happens when the wheels have been turning fast for a while.

I did once describe these symptoms to Aidan though, and he was at a loss. Might have been the way I described it I suppose.

[silverbullet]

I had already done all of the above, the gearchange was positively notchy and obstructive but only when hot.
I knew that the trans had been repaired previously though.
People often forget the state of the clutch master cylinder, which is far quicker to change than the slave!
(The drip when it leaks is hard to ignore...)

[CovKid]

Theres also another phenomenon. A dry gearchange mechanism can be very notchy, only relieved when it rains and the water underneath frees it all up. That said, above suggestions spot on, particularly slave cylinder and fluid which as said, can appear to function ok but needs replacement. I replaced mine recently. Now theres a lot more effort in pushing the pedal but it works correctly.

Pig of a job doing slave though as by the time it DOES need replacing, the nuts/bolts that hold it on will be corroded up. Irwin remover came in very handy. No way would I have shifted nuts without a set of those.

[haty167]

Cheers guys, Given me a few jobs to look into