It comes with a 3 year unlimited mile warranty
You'll probably need it...
Sorry to be negative as it sounds like you've already bought it but there are just so many bad experiences with Monster documented out there. This is the first result from a quick Google search, a member on the GMT400 reddit page who claims to be a former Monster employee.
"Not all transmissions were tested when the company claimed they were. Just built and shipped.
Too-worn used parts were put in rebuilds that were marketed as "all new".
Half of the transmissions were build by shady companies (stock), branded as monster high HP builds and shipped.
Customers shipped in their cores for rebuilds, monster would loose them, ship the customer the wrong trans back, and blame the customer. "You're ******"
3 week turnarounds were a lie, 3 months was part for the course. Staff forced to lie to customers.
Customer gets a transmission, complete dud. Customer is forced to pay round trip shipping, parts, monster trans labor, new converter, and fluid. I saw some customers (pro shops that have installed monster transmission units before without issue) have to go through this process over 4 times.
Huge turnover on staff, nobody was happy. Most builders were brand new off the street, very little experience.
Haven't worked there in 2 years. Hope they changed. Not what they used to be when they started"