NE350 gearbox

[Doudou]

Hello,

While i'm running my NZ350, the second gear (only the second) doesn't stay engaged and disengaged if i don't hold the hand gear lever.

I've open the gearbox, all the pinions seems to work well and are not damaged

Let me know your advice for origines of this problem.

thanks
ed

[Nasenbär]

Hello,
do you know the workshop manual? There you find how to adjust the shafts, maybe you should check this. You find it on www.greiner-oldtimerteile.de under Downloadbereich.
Regards, Matthias

[Frank]

Hi,

It is like Matthias writes, the adjustment of the shafts and the gear selector drum is very important.

There can be different reasons for jumping out of gear, probably there is something with the shift gear for 2nd and 4th gear, or shifter fork for those gears, but try to check these:

1.The claws on the gears are not rounded at the corners (they shall have the shape of a fish tail)

2. Check that the both gear selector forks are not bent or worn.

3.Around 0,1mm end clearance when you try to move the 4th gear (where front sprocket is attached) back and forth in the direction of the clutch shaft.

4. Zero end clearance in the lower shaft of the gear box

5. Max 0,1 mm end clearance in the gear selector drum

6. Check that the spring loaded locking lever that locks the positions of the gears on the gear selector drum works correct.

7. Check that the gear selector drum is correctly shimmed in the housing, some times you have to put shims on the upper side and sometimes on the lower side.

As Mattias writes, try to check the workshop manual, there are ok instructions how to adjust the shafts, but there is no good info about how to adjust he movement of the forks in both directions.
There are for sure different methods, but I use to do like this:

At the first I adjust the both shafts with the correct amount of shims at the bearings on the clutch side (see workshop manual).

Then I adjust end clearance of the gear selector drum in empty engine blocks with shims to a maximum of 0,1mm (mostly I try to get zero end clearance)

After that I mount the shafts, gears, shift forks and gear selector drum in the engine block (do not mount the gearbox cover yet).

Then start to turn the gear selector drum by hand, gear by gear, the check with help of a lamp and maybe a small mirror that the gears moves enough in both directions.

If you notice that some gear is not moving enough, or moves to much in a direction, adjust the movement by adding or removing shims on upper or lover side of the gear selector drum.

Notice that if you remove a shim on one side of the gear selector drum, you have to put a sim of similar thickness on the other side of the drum, so the end clearance of the drum dont change.

Then mount the gear shifting mechanism and check taht the marking on the drum align with the marking on the selector segment.

Mount the gear box cover and check that the gear works. Do I final test and put the gearbox in the 4:th gear and try that there is still 0,1mm end clearance in the gear where the drive sprocket is mounted (I seen damages on some 4th gears due to wrongly adjusted gearboxes where the selector fork attaches too much pressure on the 4th gear which damages the gear and the roller bearings).

Its not difficult to adjust the gearbox, its more difficult to try to explain it here

Dont hesitate to ask questions if I was unclear, or maybe there are other people on the forum that have some easier way to do/explain this?

Good luck with your gearbox!


//Frank

[Doudou]

Thanks for your answers, in my position, something must have been déteriorated, because i've never open my gearbox before, and it works well before !

To start with, i'm gona change all my bearings, still got a problem with these parts, i don't fine anyu modern equivalent :

n° 9912
n° 9647
n° 122224-0
n° 122232-0

Please can you helf me for that?

Also looking for the n°12245-1 pinion, the interior where the rollers "9912) goes is not very beautiful. I'd like to change it.

Let me know

Thanks again
Ed

[Frank]

Hi,

9912, bearing rollers 5x8mm are standard rollers and can be bought in shops that sell bearings.

9647 outer race, I am not sure if its possible to find new somewhere. Its the the same size also used on IZH-350 and IZH-49. Try to check with someone who is selling IZH parts. For example check with Easthighway.com in Estonia if they can help you.
If you dont find a new one, I may have an ok in used condition for you.

122224-0 same answer as for 9647.

122232-0 is a standard size oil seal and available in shops selling bearings and seals. Size 36x52x7.

122245-1 shaftrad (4:th gear) I dont think you will find a new one anywhere, but I think I have a ok used one for you.

//Frank

[Doudou]

Hello Frank

On my part n°122232-0 it's writen 57-32-9, does it mean there are two types of part 122245-1 ?

The seller only propose me a 57-32-9.5 joint, hope it will go on...

For the bearing rollers they don't find a way to get them... they only sell complete rollers Bearings And don't know size of the rollers

Let me know by mp for the 122245-1 , 9647 and 122224-0.

Thanks
Ed

[Frank]

Hi Ed,

36x52 is correct size, the thickness is not critical, so you can use everything between 7 and 9,5mm.

Sent you an PM about the parts.

//Frank