More gearbox woes

[PeterK]

Finally got my replacement gearbox in and new output flanges to suit my SC. Unfortunately, while the box sounds great in reverse and 5th, it sounds like a bag of nails or a tray of bolts being shaken in the other 4 gears. Quiet when crawling, but as soon as any power is applied, it's noisy.
Any thoughts ?
Peter

[Mike911scrs]

Hi Peter
selector shaft adjustment inside the box

regards mike

[PeterK]

Engine & box coming out (again) hopefully at the end of the week.
I'll check the 5th / idler area as Mike has suggested (thx for the photo). Watch this space.....

[911hillclimber]

My 915 alloy box rattles in 5th at low rpm, about 50 mph, silent at 60 under load.
Did that after a big Bob Watson rebuild decades ago.

[Gary71]

Anything below 2000 in 5th it rattles, but not as bad as your description. Period test reports flag this so it’s not a worn box thing.

Maybe the clamp nut on the input shaft has come loose, so it still drives but the gears chatter against each other?

[PeterK]

Hi Peter
selector shaft adjustment inside the box

regards mike

I think he knows a thing about gearboxes, does Mr B.


2.5 hours from driving it into the garage to this


Supposed to be 1mm clearance between 5th and the idler


Clearly, judging by the polishing of the teeth, I haven't got quite that much



Adjusted to give 1mm between the faces of the gear cogs. Now waiting for a new gasket and o-ring to arrive, then we can see whether it was as simple as that, or whether it's fubar

[Gary71]

That would certainly make a noise
Hope it’s an easy fix

[PeterK]

Found another couple of issuettes with the gearbox, so rather than risk it, it will have a full checkover. For those who know who I got it from, he has been a top bloke throughout.

Unfortunately, unless someone has a spare gearbox for me to borrow & fit this coming week, then given my sailing commitments that means that I'll be taking a daily driver to CLM