tr7triumph.com

This is possibly a common fault ,i have noticed small holes in my rear axle back plate the car is an1978 s reg
its 4 speed gear box ,the back plate does no screws off ,its a sealed unit ,now there are so many holes ,have used Quik Steel
compound ,it has worked for a year now am now replaceing it again ,is there an other solution ,say Tig weld
Can you buy a pack plate cover ,am now concerned if this compound pups of am in trouble

As far as I can see the 4-speed axle is composed from pressed steel parts so should be easy to repair by welding.
Cardboard Aided Design springs to mind

It's a common fault apparently. I had the same issue on mine but bought a new 4-speed axle casing from Rimmers in 2014 when they only wanted £100 for them. I presume they've probably sold out of them by now?

Actually, they've still got them at £118 inc. VAT

https://www.rimmerbros.co.uk/Item--i-RKC3302