Bloody gearbox!

[NYK]

OK gearbox is on the bench. I pulled the nose piece ( the bit inside the bell housing) to replace the seal. Unbeknownst to me, as it came off it pulled the main drive shaft/ bearing out about ??. Having never used this gearbox I thought I would check if all the gears would select, they all seemed to be there OK. When I came to refit the nose piece it would not go and I then realised what had happened. The problem is now that when the main drive shaft/bearing are pushed in where they should be, the gearbox is now in 4th when it should be in neutral and is locked when selecting 4th. There may well be other permutations of things being wrong as well. I have taken the selector cover plate off and jiggled things about a bit, ie pulled the main shaft out a bit tried selecting gears pushed it back in etc but it?s still won?t select properly. I gues something got out of sync when I initially tried selecting gears when the main shaft was pulled out. I?m no gearbox person and it?s getting rather tedious randomly jiggling things.
All bright ideas appreciated especially if they sort out this little problem!

[joe7]

I don't think the gear box is stuck in 4th its jammed by the 4th gear syncro ring not being aligned with the syncro hub.Try aligning the 4th gear syncro ring to fit into the syncro hub. There are 3 cutouts on the syncro ring that fit into the hub blocker bars. Good luck.

[NYK]

I don't think the gear box is stuck in 4th its jammed by the 4th gear syncro ring not being aligned with the syncro hub.Try aligning the 4th gear syncro ring to fit into the syncro hub. There are 3 cutouts on the syncro ring that fit into the hub blocker bars. Good luck.

Yes that definitely makes sense having just had another go at it and I concluded what you describe. However I cannot work out how to rotate the syncro ring in relation to the hub blocker bars. Should I be able to do this when everything is in situ or have buggered something?

[Craven]

With the first motion shaft (input) moved forward the gear syncro cone will be out of position, if the gear is selected the blocker bars are pushed too far forward out from their normal detent and tips into a non-recoverable position.
Bad news if this has happened, pull the mainshaft (output) and reposition the blocker bars.

[joe7]

Best guess is to pull out the first motion shaft a bit (that's how it got out of alignment) then try rotating it with a very slight inward pressure the syncro ring may slip in. If not try taking a screw driver and rotating the syncro ring from inside with some rotation on the first motion shaft. There is hope!

[NYK]

Success! Managed to rotate it with a screw driver having first pulled the first motion shaft as far forward as it would go, all gears seem present and correct. I can think of a better way of wasting an afternoon, thanks for the helpful suggestions all. Gearboxes are the one thing on a car I never touch, but hopefully it will at least be oil tight now.

[SENC]

Replacing gearbox seals is on my list for the next few weeks, so this thread will be helpful in at least one thing to try to avoid - as you get yours finished, please post any observations or advice you may have.

[types26/36]

Replacing gearbox seals is on my list for the next few weeks please post any observations or advice you may have.

If you intend to remove the four bolts that hold the bellhousing to the gearbox, the lower left bolt goes into the gearbox oil chamber.
It is advisable to seal the bolt with thread tape as it can develop a leak inside the bellhousing.

[NYK]

Replacing gearbox seals is on my list for the next few weeks, so this thread will be helpful in at least one thing to try to avoid - as you get yours finished, please post any observations or advice you may have.

Removing the seals and replacing them was straight forward, they are a very tight fit and needed quite a tap to re-seat, I used a large socket to push them in.

Clearly the biggest problem resulted from the removal of the front seal housing, I had no idea it was pulling the bearing/1st motion shaft forward. Once it?s removed, just check that the large circlip is butted up against the front of the gearbox housing, if not just push it back inwards (hindsight is a wonderful thing). My ?own goal? occurred because I selected gears and rotated the 1st motion shaft when that front housing was removed, probably best to avoid doing this!