Gearbox woes

[championdungspreader]

I think I know the answer to this...but

My gearbox for the past two months will jump out of 4th on acceleration, deceleration and any sort of drive, really, unless I keep my hand on it. I drives fine when I do this, and have done at least two 200 mile journeys like it, it is just rather irritating to have to drive like it. It is not noisy at all. Up until then, the box was fine in every way.
Is there an obvious 'this'll fix it' or do you experts agree that I simply need to put in another 'box?

As I said, I think I know what the answer is...

[bmcecosse]

Holding it in gear simply wears the h3ll out of the selector fork... Find another box asap.

[millerman]

championdungspreader

I like the user name, just like politicians spreads s**** everywhere

Ok, completely off topic. It must be the sun

[philstill]

Worn teeth on syncro hub, weak syncro hub springs, worn dog teeth on the fourth ( first motion shaft ) gear wheel, worn baulk ring, worn detent in selector rod, worn fork or displaced selector rod bearing or broken selector rod bearing spring. Could be any, some or one of the mentioned!
Phil.

[bmcecosse]

In top gear - it's more likely to be bearing trouble. Top gear syncro never wears significantly....

[philstill]

I would have thought that if it was bearing trouble, the 'box would be noisy, the chap said it wasn't, that's why I didn't include the first motion shaft bearing to my list of possible faults.

[les]

With that list you're basically saying it could be anything!

[championdungspreader]

Thanks for your advice...I'll just opt for a secondhand box then!
I dont need the car too much before a new term starts in September so I will get it done over the next few weeks!

[les]

If you get another box you may get a few pounds back for your old one. Good luck.

[bmcecosse]

You don't say where you are....but there a couple of boxes in the SALES section! Act quickly!!