Gearbox caput?

[VRS]

1983 1.9td 4 speed box. Was driving at 50mph with trailer and quite suddenly a loud rumbling noise. Pulled into layby and couldn't see anything obvious. Continued on but harsh noise only in 4th gear. My daughter came to the rescue and towed trailer to race meeting and then home again. Picked up van yesterday and made it home the 60 miles using 3 gears. There is a tinkling noise in those gears but no harsh rumbling. So, anyone know what the fault is? And can I fix it or is it toast?

[T25boy71]

Give Malcom a call he can advise repair rebuild he a good guy CV365EH postcode 

[Aidan]

I would recommend checking through the linkage thoroughly and then dropping the oil to see what the drain plug magnet reveals - no one will be able to guess what the issue is - you have a non standard engine with an unknown gearbox, and no history, it could literally be anything

[VRS]

Thanks for swift response. I did try to undo the fill plug to put some oil in before I drove it home but without success. Will get it up on some ramps to have another go and look at the linkage. What might be broken there?

[VRS]

Okay got the oil out, less than 2 litres in there. Magnet had soft shavings on it but also what looks like a piece of cog about 5mm long and about 2mm thick. The selector mechanism looks to be in good shape from the front to the gearbox including where it goes through the cross member bush. To be fair I have had no problems selecting the gears. There's a length adjustment halfway along should I try that? One thing I forgot to mention is it sometimes jumps out of 1st gear on over run. Not put oil in yet to try it out with the correct level. Hopefully Aiden especially will have a clue. Luckily I do have a 5 speed diesel box in a basket case T3 but not relishing a swap.

[VRS]

By the way I used a Triumph Spitfire wheel nut with a 9/16 socket to get the filler plug off. Perfect tool if you happen to have one of those lying around!

[silverbullet]

Why would you start making adjustments to the linkage if all gears selected easily? Be methodical.
That little piece you found is most likely a bit of synchro dog, they do come off the synchro hub on boxes that have had a hard time, its a known thing to happen.
Only two litres in the box is not a good sign, but why it is noisy only in top is one for the experts who are familiar with the internals.
Swapping the gearbox isn't an epic job, doable solo with a big trolley jack and ramps.

[VRS]

Cheers, point's taken. I do have some ramps and a medium size trolley jack but my 69 year old body ain't looking forward to it.

[VRS]

Put some oil in it and tried it out. As expected still the same although less noisy. Gearbox coming out then, manana, probably......