According to NerdWallet a traditional installment loan can help your credit score:
1.The biggest influence on credit scores is payment history, and a record of on time payments will bolster that history.
2. Make sure your lender reports your account activity to the major credit reporting agencies, Equifax, Experian and TransUnion.
3. If you only have credit cards, adding installment debt helps diversify your types of credit and might give you a modest bump.