had an employee once that put a transmission in a dodge. yup you had to remove the oil filter to remove one of the bolts for the bellhousing. well, he forgot the filter. started the thing up and 5 quarts right now all over the shop floor, what a mess. I learned a long time ago, when removing a filter to look for the oring to make sure it's on the filter. I worked in shops that guys would leave the oring stuck on the block and the customer would take their vehicle to have the seal blow out on the road, talk about ****ed customers, so that's where I got the habit of looking for the seal.