MX-5 OC Forum

Can anybody tell me if a mk2 (2003) 1.8 gearbox would fit a mk1 (1989) 1.6? Thanks

Yes it will

Great thanks :D its only that my 3rd gear has started to crunch above 2500 rpm. I've been told that the 3rd gear synchro could be on its way out? Do you think it's worth changing the gearbox oil to see if it will stop the crunch or should I just go for a new box or is there anything else I can do? Thanks

Certainly worth changing the gearbox oil (do not be tempted to use any `additive`) Redline MT90 has a good reputation in these gearboxes (2L in gearbox and 50cc in the shift turret).

You should be able to pick-up a low-milage replacement gearbox for £30-75, they are actually cheaper than the 4 piece clutch you will want to replace and, as a matter of course it is wise to replace the clutch slave cylinder while the `box is off, as they do fail eventually and can leave you stranded.

Dr. Eunos

Great thanks, awesome advice. I will definitely trying changing the gearbox oil then before swapping the 'box over. What grade oil would you reccomend? Thanks again.

Redline MT90 or SAE 75-90W

Thanks mate!

surprised nobody has mentioned the starter bolt that wont fit. To make it fit you need the baffle plate and starter from the mk2.. Or a drill.

Have just fitted a Mk2 gearbox to a Eunos J2-Limited 1994 1.8, without needing a Mk2 baffle plate.

It was a customer supplied gearbox and came with different wiring terminals for the reversing light switch etc and an electronic speedo-drive instead of a mechanical cable and the shift turret was a completely different design including the gear-stick. The switches ALL swapped over ok from the old box, the speedo-drives swapped over ok (same number of drive-teeth) and function perfectly, the prop-shaft fitted fine into the `new` box.

You must use the MK2 gear-lever  but ALL bell-housing and starter bolts will go back in with the `new` box. There is a metal bracket at the top right position (on the outer starter-motor bolt) which supports the loom running along PPF frame, the 90 degree bend of this bracket needs to be flattened out a bit to get that bolt back in

Dr. Eunos

Brilliant thanks for this!