Hi Guys,

I am really kicking myself right now. I was doing an oil and filter change on my Discovery 2 today. This is the first time I've attempted to do it since I bought the car in January. All of the bolts were extremely tight but I got them off.

I changed the filters, lovely lovely lovely. But when I came to replace the centrifuge cover I encountered a problem. I was tightening the bolts and the two most frustrating things happened. One of them (the one furtherest from the engine) suddenly wouldn't tighten or untighten anymore it is stuck, and the other has become so tight that nothing I or my friend can do will release it.

Any ideas? We are going to phone the garage after lunch. My friend (Who is a tractor mech) says that he think I'll need to replace the whole Centrifuge housing if the threads are crossed for the tight one. I guess I could drill out the other one and put a long bolt through and hold it with a nut. But for the tight one I have no idea.

Frustrating! Especially as I did the oil change as I didn't know when it was last done or in what state the filters were. I thought it was good to be safe as I am driving to Albania next week (if that can still happen). It turns out the oil was still pretty good.

So, ideas?

Did you start them off by hand or pile straight in with the heavy weapons? If they were screwing on by hand at first then they are unlikely to be crossed.

If you have done the thread in on the tight one, Google "Helicoil". These a great for thread reapairs in a blind hole.

The threads on these are notorious for stripping. It's possible somebody has previously fitted a helicoil (badly) and it's unwinding with the bolt.

You can put a longer bolt with a nut on the bottom. The good news is there's no real pressure in there so it doesn't have to be incredibly tight.

Don't worry about stripping threads just us two long bolts and nuts to secure the cap. It's easier to do the one nearest the engine with the main filter off.

Also easier to push the bolt up from underneath so the nut is on top.

I retapped mine to 8mm and I am very happy with result. Take care that no filings fall into housing.

Also retapped mine.