The very common substitution of _quick claim_ (or _quickclaim_) _deed_ for the technical term _quitclaim deed_ qualifies as a very straightforward (mortgage-related) legal eggcorn.
Wikipedia informs us that a quitclaim deed is
> […] a document by which a person (the “grantor”) disclaims any interest the grantor may have in a piece of real property and passes that claim to another person (the grantee). A quitclaim deed neither warrants nor professes that the grantor’s claim is valid. By contrast, the deeds normally used for real estate sales (called grant deeds or warranty deeds, depending on the jurisdiction) contain guarantees from the grantor to the grantee that the title is clear. The exact nature of the warranties vary from jurisdiction to jurisdiction. Quitclaim deeds are sometimes used for transfers between family members, gifts, placing personal property into a business entity, or to eliminate clouds on title, or in other special or unusual circumstances.
For the non-legal reader, this seems to mean that the term is used to describe a particularly light-weight, “quick”, way of signing property over to other people. Or in the words of our contributor Marian Neudel: “Presumably the rationale is that it is faster to process one of these than several other types of deeds, most notably warranty deeds. A quitclaim, after all, is merely a way of conveying all the rights you own in a piece of property — if any — rather than certifying that you actually own something worth conveying.”
The eggcorn is also easily understood phonetically: The hypothetical consonant cluster [tkl] in the middle of _quitclaim_ easily morphs into [ʔkl], even for speakers of dialects that do not generally realize final [t] as a glottal stop ([ʔ]). The latter would be the case for significant numbers of British English speakers (who pronounce even the word _quit_ as [kwɪʔ] instead of using the dictionary-pronunciation [kwɪt]).