This is an unfortunate situation where the law cannot help you regain possession. There are several reasons why, one being the length of time since your father's death and the original fact that the sisters never reconveyed title. This is a family issue that might be resolved through counseling or a family friend, but not through the courts.
Please note that I am answering this question as a service through Avvo but not as your attorney and no attorney-client relationship is established by this posting. An attorney-client relationship can only be established through signing a Fee Agreement and paying the necessary advanced fees.
I agree with Attorney Reed. Your father was given bad advice and there was no way for him to undo what he had done. Your aunts can choose to do so, if they are willing to. Otherwise, I am afraid that you are out of luck.
***Please be sure to mark if you find the answer "helpful" or a "best" answer. Thank you! I hope this helps. ***************************************** LEGAL DISCLAIMER I am licensed to practice law in the State of Michigan and have offices in Wayne and Ingham Counties. My practice is focused in the areas of estate planning and probate administration. I am ethically required to state that the above answer does not create an attorney/client relationship. These responses should be considered general legal education and are intended to provide general information about the question asked. Frequently, the question does not include important facts that, if known, could significantly change the answer. Information provided on this site should not be used as a substitute for competent legal advice from a licensed attorney that practices in your state. The law changes frequently and varies from state to state. If I refer to your state's laws, you should not rely on what I say; I just did a quick Internet search and found something that looked relevant that I hoped you would find helpful. You should verify and confirm any information provided with an attorney licensed in your state. I hope you our answer helpful!
The direct answer to your question is that your father does not own the house legally, but that may not alter whether or not you have a claim through child support that may give you a way to seek title. If you are not the children that were owed child support, then this argument does not help you. To avoid a child support obligation, your father made sure that his name was never on title with the idea that his sisters would reconvey title to him at a later time. That is an illegal agreement and you may have a chance to get it unwound if you can get a litigation attorney that understands the interplay of real estate, probate, and illegal contracts to avoid responsibility for obligations like child support. You say that you have not spoken to your aunts in 10 years, but you do not say when your father died. It would also be important to know when you turned 18. I work with a good private investigator out of the Phoenix area that can probably locate your aunts. You need to discuss the specific facts of your situation with an attorney to determine what, if any, claims you may have on the house. Just remember, if you were not the children owed child support by your father, then this argument does not help you and you may have no claim to the property.
Disclaimer: This answer is provided for informational purposes only, does not constitute legal advice, and does not create an attorney-client relationship. I am licensed in Arizona and can only provide general comments on matters outside of Arizona law. Actual legal advice can only be provided after a direct consultation in which all of the relevant facts are considered before providing a response.
Assuming your grandfather had such intent to have your sisters hold the property for your father's benefit (in a trust relationship) or your father had such an agreement with your sisters, the trust or the agreement that would generally have to be in writing because the subject matter involves real estate. Even so, it is unlikely that a court would uphold such an agreement because such a ruling would be tantamount to encouraging child support fraud.
NOTICE: The foregoing is provided for general informational purposes only and is not intended to create, and should not be construed as creating, an attorney-client relationship. Legal advice that you rely upon in making important decisions should only be obtained from direct communications with a lawyer licensed in your jurisdiction after there has been a full disclosure of all of the relevant facts. That said, you should never provide information that you intend to be confidential or privileged on a forum such as this, and you should never rely on information provided here as a substitute for such legal advice. Also, please note that any U.S. tax information provided above is not intended to be used, and may not be used, for the purpose of avoiding penalties imposed under the U.S. Internal Revenue Code or for promoting, marketing, or recommending any portion of this communication to any party.