I am planning to remove the gearbox on my beloved TR4A with help from a friend. Not done this before but did do the clutch on a TR6 about 10 years go, so some scant/ flimsy experience. Any advice please re; "dos" and "don'ts" to save me from any heartache, head scratching and unnecessary expense? Oh, and putting it back again, of course.That always helps, I find.