I'm after soon advice and help

Had a new clutch fitted.. Seemed all fine driving home and over the next couple of days then it suddenly got stiff to between 3rd & 4th gear.. Would still go into gear and run fine.. On further investigation noticed the gear box was leaking oil.. So was towed back to the garage... Gearbox leak fixed... But still the gearbox is tight in 3rd and 4th..

They have check the car over and Clutch is fine and gearbox fine no noise at all.. Seems linked to linkage.. This was check but nothing stood out. So they are talking about stripping the gearbox to see what could be the problem.

The car runs fine just is tight into 3rd and 4th..

All advice welcome.. Gear change is better at high revs.. So basically 6k revs +


Help!!!!!