peg away vs keep one's shoulder to the wheel

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

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

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

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

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

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