Gearbox clunk

[Apis Mellifera]

Hopefully this isn't an expensive clunk...

I have a '73 88. Just as I let off the throttle for a gear change, I get a clunk from the gear box. Letting the clutch out and giving it throttle after the gear change produces the same clunk. I can vaguely feel it in the gear lever. Any ideas? It's not the U-bolts.


Also, I've read the suggestions about checking the tightness of a gearbox shaft nut somewhere, possibly to correct a vibration, possibly the output shaft. I know that's a vague description, but does anyone know the location of this mystery nut (pictures?)?

Many Thanks
Matt

[KevinNY]

I'd also check your engine mounts and transfer case mounts.

[bearcrawl]

Remove rear prop shaft, in the center you will see a castle nut that should have a cotter pin through it. Also check the mainshaft nut. If you have a overdrive you need to pull it off and i will be clear. It's the funny looking nut over the shaft that holds everything together. 100 ft/lbs. No O/D just take off the backing plate and inspect.

Here is what the shaft will look like if it's missing the nut. Nut goes over the shaft and holds all together