JAB

Replacing valve cover gaskets. The head on one of the two recessed hex-head bolts that connects the air intake to the intake manifold got stripped when I mistakenly used an SAE that was 'close' to the required 8 mm tool. Suggestions on how to remove? TIA.

salimshah

SAE tools while working on RX ... sacrilege! Please keep the two tools separate.

First get the right nut/bolt as one should never re-use a messed up bolt/nut. [the rounding happens on one side of the corners]

Access and room is the problem. Try securing all other nuts/bolts to relieve tension on the threads of the messed up bolt/nut. If the threads are not messed up, 1/8 to 1/4 of a turn should make it operateable by fingers.

Can you tap on 6sided proper size socket on the nut/bolt? I usually keep a cheap set of sockets for this purpose.

There are different tools available that work on squeeze action instead of 3 face, 6 face fit. You can even try channel locks (but keep in mind they further messup the corners.

For ex:
http://www.sears.com/craftsman-2-pac...7&blockType=G7

Or search on turbo sockets.

I have used a cold chisel (flat screwdriver) to make a notch [perpendicular sharp blow] and then apply tangential blows, using the notch to lock the chisel head.

Once again ... please discard the messed up nut/bolt. Other wise you will regret your decision.

Salim

JAB

All of the above understood, but this is a recessed-head bolt that takes an 8 mm Allen-type socket to remove. Access is relatively good, but these are torqued down pretty well which partially accounts for it getting stripped in the first place. No way are channel-locks going to get this loose. If you look at the picture in post # 21 of your thread on knock sensor replacement - https://www.clublexus.com/forums/rx-...ement-diy.html - its one of the middle two bolts (the holes are shown but not the bolts) that secures the air intake to the intake manifold.

Baetke

You're having what we call "a bad day". But this is not a total disaster.

You can try a couple of different approaches. If you have air tools, search "Eric the Car Guy" to see how he loosens up rusted (stuck) bolts. If you just have hand tools, you will need to buy a set of screw extractors and follow the procedure shown in the following video.


Also, apply plenty of penetrating oil and patience to the problem. If you break off a screw extractor in the bolt, then you do have a disaster. You might be able to find a large enough screw extractor that it will fit into the stripped out hex hole and you won't have to drill.

For future reference, sometimes you can get a stuck screw or bolt loose by tightening it first, then loosening it. You only have to get it to move a few thousands of an inch to get the penetrating oil to really work.

insuralife

I have ground a straight blade screw driver to be narrow enough to get in the hole and then tap as I twist the screwdriver.. Tap and twist it out. I have also had to grind down the edges of a 10mm to form a pointed allen wrench and then again, tap with a hammer and twist the wrench at the same time. It will come out...

Lastly if this doesn't work use a torch! THAT WILL WORK!!

JAB

I am trying the screw extractor method; keep your fingers crossed.

salimshah

I am sure the torch was meant as a joke ... we are dealing with air intake. <- Please ignore the picture shows we dealing with the plenum.

Take it slow, the replacement bolt will be available Monday. The squeeze type wrench is available from many places for less than $1o. A worth while tool to add to your set of emergency tools. The screw extractor is too messy. Good luck. Remember torque the 0ther 3 to relieve tension. That reminds me, buy the gasket while you are at it.

If you cant get to the shoulder of the bolt, extractor is the only way out. While drilling, put plenty of grease on the bit to collect all the burs.

Good luck

Salim

insuralife

JOKE?? ME?? Never! Last time I used a torch to fix my Ford Custom, I ended up with enough insurance money to buy the girfriend a Lexus!
I think it's a great tool!!
JAB, I wish you the best of luck... I do agree, use heavy greese on everything, the little burs will cause you a problem.

code58

For the life of me I don't see any Allen head screws (bolts?) in that area. I do see Torx head bolts (some people refer to them as "Star" but Torx is the official name) but no Allen. One other piece of information, I do agree with Salim on keeping US tools far from a foreign car. Having said that, there are US sizes that are identical to metric. The one that I used routinely is 5/16 which is identical to 8MM. No problem with stripping there because of wrong continent.

JAB

Interesting that you say this, because the proper size for this particular bolt is 8 mm but I used a 5/16. Yes, they are close, but they are not exactly the same; an 8 mm is 0.3149 inches, and the 5/16 is slightly smaller at 0.3125.

engine89

You are correct No metric tool is identical in size to SAE. Torx bolts are stand alone, metric and SAE do not apply.

code58

Admitted, they are not IDENTICAL, but the faint difference couldn't possibly be the reason it stripped. Tightness may have been, but tools are rarely THAT exact in their measurement when hot stamped. I was micing some drill bits last evening (good drill bits) and even they were not all exactly the same size shaft. I had 3/16 in. bits that mic'd that much different on the shaft. I can't imagine any tool being within 2 1/2 thousandths tolerance unless it was for spacecraft.

engine89

Close only counts when playing horseshoes. When you have a possible seized bolt those thousanths can make a huge difference. If it calls for 8mm get one. Once you round it out its game over and time wasted with plan B, C, etc.

salimshah

Sorry OP .. this thread seems to tilted towards tools ...

Personally, I have issue with the hardness/softness of the bolt-head/nut. Even with the 'right size' socket, if the ratchet has a slight tilt, it messes up the corners. I am slowly building my 6pt socket set.

Incidentally, service manual always show a "T" shaped tool [ratchet is a side ways "L"]. The "T" shaped tool would sit straight. Any one used it or seen it being sold?

Salim

insuralife

You're not going to believe this, but I was working on a different vehicle model ('68 Cobra) and I have a number of allen head cap bolts on the engine. Well, one of the heads stripped when I tried removing it. I remembered this thread and I took a torx tip and beat it into the waddled out hole in the cap... it dug in nicely and allowed me to remove the bolt. I'm guessing it with stood a 40-50 lb torque...
My suggestion 3/8 drive torx socket on a hand-held impact driver... It will come out.

(I still say keep the 'torch' in close proximity... the engine will see it and get the hint, and release it's hold on that bolt!)