I have a 2007 Mazda SP23 with a manual gearbox that has started to exhibit an unusual problem.
Around town, the gear change is as normal but once I have gone 15 - 20 klms on the highway and the vehicle has reached normal operating temperature it is near impossible to get it out of 5th or 6th gear. After coming to a stop and when it does finally agrees to change into neutral it is still difficult to engage another gear, particularly across the gate into first or second.
Leave the car for a short time and everything returns to 'normal'
I have been googling Mazda manual trans issues with shift cables and gear lube seeming to be common problems.....Could anyone shed any light on this problem?

Many thanks

 

Drain the gearbox oil and refill with Castrol VMX. Go for a drive & see how it behaves.

 

Thanks G_R

I'll see if I can get down to Supercheap before they close...

 

Many thanks G_R,

I changed the transoil as you suggested, went for a nice long drive and it appears to be all fixed!

 

Cheap fix.

 

My son has got the same car and the same problem. Changing the oil was my next step as it was last replaced 50000km ago. Even though the level checks ok and it looked clean. However I don't know what brand it was .

Other steps Ive done prior to changing the oil which have made significant difference but only when cold:
Sprayed cable lube on the shift cables.
Removed the part of the selector on top of the gear box which the cables connect to and gave it a clean and regressed . Ive got a new rubber boot coming from Mazda as the original one was torn . ( re greasing this bush made the biggest difference for the shift ever returning to centre when cold but unfortunately after a run gears still hard to change ).
Hopefully will have good news after the oil is changed.

Pulled apart cleaned and re greased shaft and bush . Doing this helped the gear stick return to centre easily when the car was cold .

 

I replaced the gearbox oil today with Castrol VMX-M . Not sure if I should see results straight away or whether I should have just used VMX.
I had already bought the VMX-M so that's why I used it . I have read that others use Redline and swear by it . Would be good to hear if anyone did see an improvement when changing from VMX to Red Line . ( I can say there wasn't any noticeable difference when I did the same change in my Cruiser ).

Is there anything else I should be looking at ?
I'll try Nulon G70 next before perhaps looking at changing the cables.
Has anyone changed the gear shift cables and seen an improvement ?