Gear Selection Issues

[HalfMoon]

Fitted a new clutch + slave cylinder and while I had the gearbox out I drained and replaced the oil.

I'm now having issues getting the 'box into gear - but only after driving for a good few miles. I'm 99% sure that the clutch & slave are working fine as when the issue starts & I get it into gear, the biting point remains the same so my suspicion is that the gearbox isn't liking the oil that I replaced it with (Halfords 80-90 It was all I could get hold of at the time...)

Has anyone else experienced similar issues? I'm going to change the oil for something better when I get the chance but does anyone have any other suggestions

Edited by HalfMoon on Wednesday 16th May 11:09

[designforlife]

That gearbox oil doesn't sound right to me...75W-90 is the recommended so i'd drain it and replace with that and see.


MX5 gearboxes are fairly sensitive to oil, and changing to a good quality one (ie. redline MT90) can really help.

What backs up the oil being the culprit to me is that it only starts to get worse when the box warms up.

[hms]

Was the ppf frame realigned?
H

[only me]

Just out of interest do you know how much oil is needed to fill an empty box ? and any good ideas how to get it in the side fill hole ?

Cheers Tony

[HalfMoon]

designforlife said:

That gearbox oil doesn't sound right to me...75W-90 is the recommended so i'd drain it and replace with that and see.
MX5 gearboxes are fairly sensitive to oil, and changing to a good quality one (ie. redline MT90) can really help.
What backs up the oil being the culprit to me is that it only starts to get worse when the box warms up.

Thanks for the confirmation - will definately change it and report back

hms said:

Was the ppf frame realigned?
H

I had to pull it to the side to drop the 'box out but when replaced it realigned to it's original position. Would this make any difference though, as surely the engine & box are one solid unit when bolted together and as the shifter is part of the box there's no adjustment there?

only me said:

Just out of interest do you know how much oil is needed to fill an empty box ? and any good ideas how to get it in the side fill hole ?
Cheers Tony

It's 2 litres if I recall correctly. To get it in, I used the bottles with the flexi pull out nozzles and just contorted and squeezed until I got it in (phwoar!)

[HalfMoon]

Just to update this - finally got a chance to change the box oil to MT90 today and it's cured.