oil filter doesn't snap into cap

[Idahoser]

Forgive me if this has been covered elsewhere, perhaps my googl-fu is weak. And of course I'm n00

I was able to find this thread
Job 1 Oil Change Help

in a different part of the forum, I think it's the same filter... but I wanted to find people who knew my engine to discuss this with.

I bought this truck used just a couple weeks ago, my first diesel. As a routine part of buying used, I always start from zero with all new fluids and filters. So, I took the last week going to various places to gather the Rotella T 15w40 (my Wally World had 5gal, 2.5gal, gal, and qt sizes... guess there's a lot of demand around here), FL-2016, FD-4616 and FA-1778.

When I removed the cap for the oil filter, the filter was still sitting in the receptacle, not attached to the cap. There was a 3/4 circle of plastic on top of the filter. Like a broken gasket, maybe.

The new filter does not snap into the cap. There doesn't appear to be any 'lip' for the filter 'tabs' to fit behind, I can't see any place a 'snap' could take place.

Unfortunately I threw away the old filter and the plastic piece, so I can't take photos. I've already put everything back together and drove it to work this morning, but this has been bugging me and I want to ask the experts before I put too many miles on it, just in case I'm not getting filtered oil or some other nightmare.

Looks like $30 or so for a new cap, or a lot less from dieselfiltersonline.com. I'm almost certainly going to order the cap anyway, I just don't know how urgent it needs to be.

Suggestions?

2005 F-250 SuperCab Long Bed 6.0L no known mods
getting 17-18mpg on the first three tanks so far, mixed driving. I like being able to use the grocery store discounts again, had been using ethanol-free in the Ram I traded in, harder to find.
I researched a lot before narrowing my choices to Rotella T and Rotella T6. The truck won't see much hard work, it's mostly for getting the 12 miles to work and back in traffic, with 20+ mile trips to branches a time or three each week. Rarely anything a car couldn't handle in the back; towing anything less than once a year average.
[so why did you buy a diesel?] just wanted it. With this mileage, the larger tank and discounted fuel, its' much better than my old gasser.

[Idahoser]

well, I guess nobody else has seen it, but I got the new cap today and swapped out my mystery cap. I just wasn't looking hard enough before, it's a good cap with a broken top from an aftermarket filter stuck in the top. Removed that and all is well, I'll keep the old cap for a spare.

FYI I got my first filter from Wally World, the tag on the shelf said FL-2016W but there was no W on the boxes. To see what difference there was I ordered a W along with the cap, and I got exactly what's on the shelf here with no W.

[forddieseldoctor]

I have seen that before, but I didn't see your thread till now. Plus remember a pic is worth a thousand words when your trying to describe odd problems like this one.

[Idahoser]

yeah, sorry about that, it bothered me more as I thought about it but by then the parts were gone.

Now I know. Thanks!

[96F350KID]

I'm not gonna lie when these engines first came out i did that lol. I still have the extra cap i bought!! LMAO