1300fwd gearbox worrying rattle?

[epcot_pete]

During my 1300fwd restoration, I overhauled the gearbox replacing the 3rd & 4th gear and selector fork, some bearings, syncro rings and new drive gear with matching drive shaft. Incidently, the gearbox is a 1500fwd one and has no part number marks. I have also renewed Clutch and pressure plates, thrust bearing and clutch slave cylinder.
I have this 'rattle' noise when taking up clutch during starting off and sometimes at high speed, well about 60!, you can just hear it.
With the interior parcel shelf, carpets and metal cover off you can exactly hear where the rattle is coming from and even feel it - something is touching the outer pressure diecast rear end cover on the inside as the drive is taken up. It is like a tapping noise, once drive is taken up the noise goes away. I suppose I could take the gearbox out and see some sort of marks on the inside of the cover and take appropriate action.
Could any kind person offer advice as to what could cause this noise? The gearbox itself works well and has no noise after the initial start off apart from a similar but quieter 'rattle' from same place at about 60mph.
To take the gearbox apart I need to take engine out etc, so is the 'rattle' serious and can I drive it for the rest of the season?
Appreciate any comments.
Pete

[re5rotary]

Hi but you don't need to take the engine out to look at the gearbox, just pull out the parcel shelf and the rest of the carpet and trim in that area. Take off the tin cover and you can do the lot from the inside of the car. Certainly you could easily take off the alloy end cover regards Terry

[epcot_pete]

Thanks Terry, problem I have is that when removed it should show 'marks' but then I probably have to strip the box down to correct the fault and it would have to be taken out then.
Really appreciate comment.
Pete

[re5rotary]

Hi well actually you can dismantle and rebuild the gearbox from the inside the car, it doesnt have to be removed. That was one of the clever parts of Triumphs front wheel drive setup regards Terry

[epcot_pete]

Terry, my apologies I did not know this and it would save me a lot of hard work. I will be going to the annual get together in September and ask other 1300fwd owners of what they think the noise/rattle is.
Many thanks for your time
Pete

[epcot_pete]

Well I finally found time to strip the gearbox down from inside the car and found the suspect marks on the inside of the alloy cover. They were caused by the end of the 1st & 2nd selector shaft rattling against the cover. I thought maybe it would be the new 3rd & 4th selector shaft, but not so as no mark. I can only think that the split collars and retaining rings have been refitted into different places on the main shaft, therefore giving more end to end clearance. So I ground about 1.5mm off the selector shaft and it now does not rattle except when changing down from 3rd to 2nd and you can just about hear it. I have not fitted metal cover, sound deadening, carpet or parcel shaft yet so I expect an awful amount of noise will disappear!