I'm Still putting the j pins to lock the BH subframe but it doesnt look like i need to also attach the check chains. The lower arms are not going anywhere with the backhoe on.Just checked the install manual and unfortunately yes. It is the only thing that is locking the subframe in place. If it helps though it looks like the three point lower arms, lift links and check chains can be removed. Don't know why they show it still in place when the backhoe is installed. That doesn't make much sense.