TE449 valve cover bolt removal

Greetings:

In preparation to remove my valve cover for breather drilling, I tried loosening the mounting bolts, and almost stripped one hex head because of the wrench not being fully set. Anyway, I started thinking about how to ensure maximum grip on the bolt heads, especially considering they are shallow with a built-in washer. It turns out that, although they are 8 mm, a 5/16" wrench/socket fits tighter, as it is 7.9375 mm. If you can get a six-point wrench/socket, even better. HOWEVER, sockets and wrenches both have one design element wherein they are slightly chamfered at the openings, which doesn't actually contact the bolt head flats. I thought about it, and decided to take a 5/16" six-point deep socket, then trim the end square, so that the six points are right at the end of the socket. Next, because of clearance issues for wrench handles, I cut off the square drive end of the socket, so now it is a shorter socket, with a hex hole all the way through. The last thing to do is take an 8 mm hex key, and cut off a short, straight section, then put the socket on the bolt, and the key segment in the other end of the socket. You then use a 5/16" box wrench on the key end. That way, you get maximum grip, and maximum clearance.

I used a regular wrench on mine and didn't have a problem. I just made sure to push down with my free hand where the bolt was to make sure it was a little secure.

Good idea. Well done, a bit of home engineering/ingenuity-love it

Thanks for your reply.

That's great you were able to access it so readily, but some seem to have configurations that make it impossible to securely position a wrench. In my case, the coil retaining bolt is in such a place that a socket won't fit with either an extension or a u-joint, and a regular wrench won't clear the plastic flange surrounding it. I cut through the flange wall with a Leatherman-style saw, then nibbled away at the flange with the needle-nose pliers. A regular wrench then fit properly, and I was able to break the bolt free.

One of the main contributing problems is that it seems that many fasteners are either over-tightened at the factory, or else corrosion locked them in to a certain extent, because there's no way in Hell these things have been tightened to 6 lbs.-ft. of torque (for example). If we combine initial over-tightening/corroding, shallow bolt/nut faces, and inaccessibility, we get a recipe for rounding, and then what do we do? I am unwilling to TRY it, then have it round, and now I can't get it off.

Currently, I am getting ready for another oil change, but have found (like some others) that metric/Imperial sockets are either too tight or too loose. I don't want to "pound" a 21mm socket onto the filter cap, and risk damaging something elsewhere because of the shockwaves. I am going to try using some unneeded feeler gauge shims on too-big sockets, or else enlarge the too-small sockets with a grinding bit in a rotary tool. I haven't decided yet.

It sound like you need a better set of sockets.

BTW, I used a ratcheting wrench (not a socket) to get my valve cover off. Worked fine. Yours must have been way over tight. Are you the original owner?

I just took a 6 point boxed end wrench and ground down the bottom of the head so it would seat good. It works perfect.

Paw Paw

I have found the oil filter cover to be 22mm by the way

Yes, I'm the original owner.

I guess it depends on each individual's situation, as evidenced by responses here, and posts elsewhere.

Other posts have commented about a 22 being too big, and a 21 being too small. Luckily for me, I only need to get it off, as I will be replacing it with a magnetic Zip-Ty cover that has a 3/8" square hole in the center for a ratchet.

The key to not stripping off the oil drain caps and oil filter cover is to not over tighten them when installing.
The caps all seal by o-ring seals, they will seal when done up by hand and only need a nip more force to stop them coming loose.

I now have 260hrs on my engine with oil changes every 5 hrs....
All original oil drain and filter caps.
Another good point is to use six point sockets and/or a brand that uses the 'flank drive' system.