Sepertinya, gear di sini mengambil makna (dari kamus Oxford): equipment or apparatus that is used for a particular purpose (alias peralatan khusus).

√ tow gear berarti seperangkat alat untuk menarik / menderek (di darat) atau menunda (jika di laut).

√ retriever adalah penarik. Dibutuhkan konteks lebih lengkap untuk memastikan apakah ini sekadar alat ataukah mesin / kendaraan.

REFERENSI ★★★
http://www.google.com/patents/US3041996
This towing gear has heretofore had the disadvantage that the tow line was retrieved to the boat by hand and often became tangled while being stored or played ...