MK1 Eunos gearbox change

[Elroy Blue]

My Father in Law's gearbox has gone on his Mk1 1.6 Eunos. Can anybody point me in the direction of a good step by step guide to changing it, preferably with some photos. He's got a reasonable knowledge of mechanics, but it always helps to have a bit of help.

[LordJammy]

Here's a guide for changing the clutch. Shows you how to undo the gearbox.

http://www.miata.net/garage/clutch2.html

[MG CHRIS]

Elroy Blue said:

My Father in Law's gearbox has gone on his Mk1 1.6 Eunos. Can anybody point me in the direction of a good step by step guide to changing it, preferably with some photos. He's got a reasonable knowledge of mechanics, but it always helps to have a bit of help.

If you haven't got a ramp don't bother it can be a ball ache on a ramp let alone 6 inches off the ground.

First time will take around 4-5hrs the top bolts on the box and starter motor are awkward to get to and the bolts holding the ppf frame to the box are tight and the ppf does get in the way a lot.

[anonymous-user]

I found it easier to remove the whole engine and gearbox as one, trying to get any access to some of the bellhousing bolts seemed almost impossible even with the car on ramps. I can't imagine trying to fit a new clutch and then put the box back on while laying under the car, and I'm not sure if there was even room for the gearbox to slide out from under the car.

The only issue I found when replacing the engine / gearbox as one was that I put the camshaft position sensor unit back on before I fitted the engine and it made it tricky to get the engine far enough in to drop down into the position - in hindsight it would have been far easier to have left that and the cam cover off and fitted them afterwards.

[snotrag]

Definitely that - engine and gearbox out as one.

[Clark3y]

Done it numerous times, it's not more or less difficult than any other FR layout car. Quite doable on stands.

[Elroy Blue]

Thanks everybody. A mechanic mate has offered to do it for £100. Doesn't seem much to save skinned fingers and all the hassle.

[pewe]

Elroy Blue said:

Thanks everybody. A mechanic mate has offered to do it for £100. Doesn't seem much to save skinned fingers and all the hassle.

For that price bite his hand off - ask me how I know.

There are lots of other posts here and other sites and "To Do" jobs whilst the box is out but consider:
Deffo Clutch. (Mazda OE Thrust bearing is best even if you are using after-market clutch and pressure plate)
CPS O ring
Blanking plug just behind the CPS.
Gearbox first motion shaft oil seal and casing gasket.
Gearbox tail shaft oil seal
Heater hoses
Thermostat whilst the coolants drained
Engine mounts
Gear lever nylon bush

HTH.
Cheers, Pewe

[Elroy Blue]

Thanks for that. The car itself is my FiLs pride and joy. It's been kept in a carpeted garage since the day he got it and has been waxoyled and treated better than his wife since day one. It only does around 2000 miles a year in the dry. The car suddenly got stuck in gear and he's done a bit of online research and is pretty sure it's the gearbox. Replacement second hand ones are only around £50, so he's changing it.

My mate is going to check all the bearings first before replacing it.

[MG CHRIS]

for £100 that cheap I usualy charge around that when I do clutches on mx5. Yes they can be dropped down from underneath which is easy on a ramp.

On the floor though the way of doing it is engine out with box.

[MX-5 Lazza]

Agree with that. I've done a gearbox change on axle stands just dropping the 'box and it was no fun at all. Especially refitting. It took 5 of us all lifting, pushing, shoving & jiggling the bloody thing to get it engaged. That was worse than getting to all the bell housing bolts which isn't that difficult with enough socket extensions with wobble-bars.

[pewe]

MX-5 Lazza said:

Agree with that. I've done a gearbox change on axle stands just dropping the 'box and it was no fun at all. Especially refitting. It took 5 of us all lifting, pushing, shoving & jiggling the bloody thing to get it engaged. That was worse than getting to all the bell housing bolts which isn't that difficult with enough socket extensions with wobble-bars.

For future ref, Lazza, make up a couple of slide pins by chopping the heads off spare gearbox bolts and slotting them to aid removal. Last time I did mine I also used an angle guage on the box and sump to ensure both at the same angle - box then slid in like a rat up a drain-pipe.
Having said that I did make up a cradle to fit onto the trolley jack so I wasn't supporting the weight unaided! BTW anyone local to Reading is welcome to borrow the cradle.
Cheers, Pewe