1.6 & 1.8 5 speed

[Forced Fives]

Can anyone confirm that the 5 speed from a 1.8 bolt straight into a NA 1.6 without midification or are there differences between the gearboxes?

Are the NA & NB 5 speed also the same?

Thanks

[Russellb]

I think the NA 1.6 and 1.8 G'boxes are the same but I think the NB 5 and 6 Sp Boxes take a differant Starter motor I am sure that I will be corected if I'm wrong

[kula]

^^^
afaik that's true.

[Roderic]

Doesnt meam you still cant get a 6 Speed box into your NA ;)

[Russellb]

I know now have a 6 sp in my old man's NA6 Just used two bolt instead of 3 to hold the starter in

O and the NB box has a different Stick

[Roderic]

Different stick?
Do you mean the screw threads are different? So a gear knob from a 5 speed wont fit onto a 6 speed?

[Russellb]

NA 5 sp has single pin the NB 5 and 6 sp have 2 pins
Also some 6sp have a small ball end some have a big ball end
Hope this make sense it been a long day
Threads are the same

[Forced Fives]

Thanks guys.

So any MX5 5 Speed box should bolt straight in ?

[Boyracer]

Any gearbox bolts straight in definately...

The 1.8 gearbox has double syncro on 2nd. gear...pretty much the only difference.

As Russel said the 6 speed bolts in but you just use 2 bolts on the starter or fit the later starter...the 6 speed has different wiring but thats easy to fix.

[Boyracer]

sorry to hijack, but my question is in relation to the na6 and na8 gearboxes.

which one would be more stronger?

apart from the 2nd synchro on the na8 are there any other differences?

where are the startor motors located?

and finally are the bell housings on the na6 and na8 gearboxes removable?

cheers guys

All 5 speeds about the same strength...double syncro just makes smoother gear shift.

Starter motor is under inlet manifold at back of engine.

Bell housing is part of gearbox.

[CT]

sorry should of said 5 speed only, i think the 6 speeders have a different ration 3.9 / 3.6??

while the five speeders are a 4.11

That's the diff ratio - totally independent of the gearbox.

[Moggy]

I think the NA8 gearbox has a larger input shaft than the NA6. The throw-out bearing definitely has a larger internal dia. on the NA8 5 speeder. This would tend to indicate that it is stronger. However, I have put 130-odd rwkw through my NA6 gearbox for a while now with no ill effects, and I haven't heard of this gearbox having strength problems...

Edit: I should have added that although the input shaft is bigger on the NA8, the spline that goes into the clutch plate is the same size and as someone has pointed out earlier in this thread, all NA and NB gearboxes will bolt up to an NA or NB engine.