keep one's shoulder to the wheel vs peg away

keep one's shoulder to the wheel and peg away both are verbs.

Word	Noun	Adjective	Verb	Adverb
keep one's shoulder to the wheel	No	No	Yes	No
peg away	No	No	Yes	No

As verbs, keep one's shoulder to the wheel and peg away are synonyms defined as:

keep one's shoulder to the wheel and peg away: work doggedly or persistently

Other synonyms of keep one's shoulder to the wheel include keep one's nose to the grindstone, plug away, slog.

keep one's shoulder to the wheel (verb)	peg away (verb)
work doggedly or persistently	work doggedly or persistently