[Advaita-l] Gurubala in Upanayana

[ravi chandrasekhara]

Pranam to all,
For a Braahmana male, upanayana should be done earliest 8 years of age and limit is 16 but practically we have seen it done at later age.How important is it to have gurubala in the vatu's janna kundali (horoscope) ? I have heard that when upanayana was performed when there was no Gurubala, untoward things such s death, etc have occurred to the boy or close family members. What have our Shankaracharyas or dharma shastras said in this matter ?
Dhanyavaad,Ravi Chandrasekhara