Hard/impossible to shift in 3/4/5 after prolonged highway driving

[_Madman_]

I think I have noticed this behavior earlier, but not so pronounced, so I never really payed attention. But yesterday I drove around 200km, and after a prolonged period of 5th gear cruising, the car started to act up when I wanted to shift into 3/4/5. Almost as if I was trying to shift against a rubber bushing or something. A soft blockage with no grinding.

After I stopped, shifted to 1st/2nd, and started to drive actively again, lots of revmatched downshifts, upshifts, acceleration, decceleration while in gears, the tranny started to shift silky smooth again.

What could be the reason? Overheat? Loose fork? Clutch sticking? No idea where to start looking.

 

[PieEyedPiper]

Pedal pump up? It's just a nice thing to cross off the list. Do the slave rod test just to cross it off. I assume everything is working fine with the car off or in neutral?

 

[_Madman_]

After pump up it starts to shift. What is it?

 

[black_gst]

Pedal pump up? It's just a nice thing to cross off the list. Do the slave rod test just to cross it off. I assume everything is working fine with the car off or in neutral?

doesnt sound like pump up to me.

when was the last time you changed your trans fluid? and what fluid do you run?

also it could be a bad master clutch cylinder, when the engine bay temps get up there and the fluid get hot it could be causing an issue or even just old clutch fluid.

 

[_Madman_]

I change transmission fluid regularly, with each transmission tear-down. 3 times in 2 years or something

I run Castrol GLX or something now, GL4 and weight as per manual, can't remember exactly. But it's the oil Evos use, so I guess it should be good.

The clutch reservoir has some blackish fluid in it.

 

[black_gst]

I change transmission fluid regularly, with each transmission tear-down. 3 times in 2 years or something

I run Castrol GLX or something now, GL4 and weight as per manual, can't remember exactly. But it's the oil Evos use, so I guess it should be good.

The clutch reservoir has some blackish fluid in it.

Id change out the clutch fluid, it might be bad. just bleed it all out and get some good fluid in there. If that doesnt fix your problem, id change out your clutch master and slave. I always change both at the same time if they both have some miles on them.

 

[PieEyedPiper]

doesnt sound like pump up to me.

Not entirely, no. But he did say it all goes to hell after driving in 5th for a while and that's classic pump up. Still just a nice thing to cross off the list.

If your fluid is black, I'd agree it's likely time for a friendly flush/bleed of your hydraulics. At least every 6mo. to a year I do it and I'm always met with improved shift quality.
Black fluid is a nice thing to cross off the list.

Could even be a tired old slave. Just start doing the easy and basic operations, if you haven't already.

If it were me I'd:
-inspect clutch adjustment
-inspect master cylinder
-inspect slave cylinder
-inspect clutch fork
-bleed system

and then we go from there