 Nyorai kupfuurira kweiyi ndima - Akapinda muchiuto musi wa 4 Ndira 1954 somudzidzi wechiuto. Geldenhuys akawana BMil kubva kuYunivhesiti yePretoria muna 1956 asati ajoina 1 Special Service Battalion. Muna 1965, akaendeswa kuSouth African Embassy muLuanda, Angola semutevedzeri wemumiriri, chinzvimbo chaakabata kusvika muna 1968. Akagadzwa saChief of Staff Intelligence uyezve Chief of Staff Operations. Akaenderera mberi nekuve mukuru wemauto muSouth African Army, achishanda semutungamiri weSouth West Africa Command kubva muna 1977 kusvika muna 1980, paakagadzwa kwenguva pfupi seGeneral Officer Commanding weSouth West African Territorial Force. Gare gare muna 1980, akava mukuru wemauto. Geldenhuys akasimudzirwa kuva mukuru uye akatora chinzvimbo cheMukuru weSouth African Defence Force musi wa31 Gumiguru 1985. Muiri basa, iye akatora rutivi munhaurirano dzakaunza Hondo yeMuganhukusvika kumugumo muna 1989, pashure pemakore 23 okurwa. 