Gearbox rebuild advice

I'm trying to strip down my gearbox however now I've become stuck. Two of the detent balls have been removed with ease via a magnet however the middle ball is not shifting. Can anyone offer any advice? I've tried a pencil magnet however it just doesn't want to pop out of it's bore. Without removing this I can't split the box.

Have you tried operating the gear selector? That ought to shift it, certainly enough to remove the casing.

Thanks for the reply Rachael. Can I just confirm with you something? I have undone the bellhousing bolts/nuts that separate this housing from the main gearbox/ diff. The aim to split the casing into two parts. As there is only one detent ball left which is stuck, am I right to say this is the only thing that is stopping the two casings coming apart? If so do you think I should turn the gearbox over so the bore of the detent ball housing is to the floor and then try and wiggle the selector fork, in hope that this ball drops out? I can see three selector forks from the end of the gearbox that has the circlips attached.

You're welcome Damon! I must say the detent ball would have to be well jammed to stop the casing coming off. Have you undone the bolts from the clutch side? Have you removed the circlips retaining the bearings?

I've removed all bolts that I can see. Bolts inside the housing and around the outer casing including diff area. Yes, also removed the two large circlips behind the small cover. Removed the detent springs then realised two springs are the same compared to the third. Think the fatter/ smaller spring is reverse gear spring?

The casing moves apart only a few mill so I guess it's this ball that's stopping it?

If the box changed gears normally, the ball should be able to move far enough to let the selector shaft slide past it. If the case moves a few millimetres it may just be snagging on the studs that hold the halves together, or the circlip groove edges in the bearings may be catching on the bores in the casing. Have you removed the bearings? Try levering the case halves apart gently, but protect the mating faces.

No I haven't removed the bearings, so perhaps I'll do this. I only took the circlips off and the washers.

Don't know if you know why I'm doing this, as I've had a horrible rattle when the car idles. When I press the clutch pedal noise disappears. I've already bought new clutch kit. I can only presume it's the gearbox bearings however once I've split this gearbox apart I'll have a better idea. Also occasionally car would jump out of third gear when on and off throttle. This could just be lower gearbox mounting which mine looks a bit knackered or maladjusted linkages under the car. Have you any thoughts?

Have you removed the large circlips around the outside of the bearings? Actually, if you have removed the smaller circlips and Belville washers, you should be able to lever the bearings out of their bores leaving the outer circlips on.

Rattle at idle could be gear chatter or the clutch disc springs failing. If the bearings are failing the gearbox will groan or howl, the noise may get worse as you go through the gears. If the gearbox was quiet the bearings should be ok. Jumping out of gear could be a problem with the bottom mount.

Have you thought about getting a 5 speed gearbox or do you want to keep it original?

I've removed the smaller circlips and I do remember the bearings moving around in the bore so I'll pull these out before pulling the casing apart.

When driving gearbox is perfect no crunching or noticeable noise. I will be buying a new mount as well.

I did think about 5 speed option however want to keep car original. I like the 4 speed box.

I'll let you know how I get on in the next couple of days .

Thanks Rachael!

No worries - good luck!

Damon Singh wrote: ...a horrible rattle when the car idles. When I press the clutch pedal noise disappears.

In my (limited) experience that is usually the clutch release bearing. If you have bought a full clutch kit then the new bearing will be included.

Andrew.

I'll be replacing the release bearing as the clutch is being replaced.

I know it's late on a Friday night but just to update you I have now managed to dismantle the gearbox. Once the two outer bearings were removed the casing came off easily. The detent ball is sticking in it's bore however I have managed to remove it. I'll need to inspect the bore over the weekend. Now is the diagnosis part of why the gearbox is rattling in neutral? Third gear occasionally pops out?

I have noticed some of the bearings on the two shafts do have play on them and when you spin them some don't seem smooth. I know there not cheap, however wonder for peace of mind whether to replace them. Also noticed slight chipping on the third gear edge. Will have to read through the rebuild article on X1/9 WIKI forum.

Well, I have finally dismantled the transmission. I have found that some of the bearings (four in total), one is slightly noisy when I rotate it and the others seem to have a little bit of play when I have put them on a shaft. Should there be a small amount of play measured with my hand?

Also the sliding sleeve which mates against 3rd gear, the teeth are worn quite badly compared to the opposite side which mates against 4th gear. In addition the 3rd gear teeth are worn. There seems to be a bit of wear on the teeth on 1st and 2nd also. Can anyone let me know how far the wear needs to be on the 1st & 2nd gears as these are quite expensive to buy? I have never had any crunching of gears just popping out of third.