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Guest Message by DevFuse

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torquing head nuts/special tool (NOW WITH BP's PICTURES!! )

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16 replies to this topic

#1 Guest_soobiedoobie_*

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Posted 14 November 2002 - 11:44 AM

ive seen a few threads about blown head gaskets so i thought i would check the torque on my heads like it says for maintenance. hopefully avoid gasket job. so you need a special 17 mm socket. can't get to 3 nuts nearest rocker arms. manual calls it a thin wall but i don't think that will work. seems like it needs to be a really short socket to get under the rocker. i was thinking of trying to cut down a regular socket. any one try this? thx

#2 Guest_Bill Putney_*

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Posted 14 November 2002 - 12:20 PM

Yes - I've done it, and it works. Started with a brand new 3/8" drive Craftsman socket because I knew I was going to be removing metal and would weaken it (it would be interesting to see if Sears would honor their guarantee if it broke after grinding it). :lol:

I didn't find that thin wall was necessary - just a severe adjustment in the height as you suggested (and if you want to make extra work for yourself, just start with a deep well socket). :rolleyes: Grind the bolt head engagement end of the socket to just slightly shorter than required to fully engage the full bolt head height (i.e., 90% engagement is plenty adequate). Then grind the ratchet engagement end of the socket to where you just start cutting into the detent recess for the ratchet ball (be sure to leave enough metal for the detent action to hold the socket to the ratchet extension). Then grind around the OD of the ratchet end of the socket with a shallow bevel to give added clearance around the edges to help with rotating in and out from under the camshaft.

I had plenty of clearance to get that modifiied socket on all head bolts with no problem. If you're doing this with the engine in the car, it helps to be trained in braille to reach everywhere, if you know what I mean (maybe borrow a compact mirror to look around in there once in a while to get your bearings). Keep a photocopy of the picture of the head and bolts from the FSM handy so you can keep refreshing your mind on approximately where the individual bolts are as you get to them, and follow the numbered order of tightening. Don't be surprised if the bolts don't move at all, but it will be good to know they're tight. Ounce of prevention...and all that rot. (you have to read that last bit with a British accent)

#3 Guest_baccaruda_*

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Posted 14 November 2002 - 12:45 PM

you could take the cam cases off and that will give easy access to all head bolts.

#4 Guest_captcu_*

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Posted 14 November 2002 - 04:29 PM

If you are talking about an EA81, you can get to them with a flat wrench. Now you need to come up with some way to attach your wrench to your torque wrench. You could use 2 nuts held together by a cut off bolt. One fits into one end of the wrench and the other allows you to put a socket on it. I actually welded a 1/2 inch drive to a 17 mm wrench. Now if your extension/wrench is at 90 degrees the torque is the same. If its straight in line, then you have to back calculate the setting on your wrench. Here's an example. Suppose you want to torque to 20 ftlbs. and you have an 18 inch torque wrench and 6 inch wrench.

Setting = 20x(18/(18+6)) = 15. So set your torque wrench to 15 ftlbs.

If you have to go at an angle, you use the imaginary length straight along the length of the torque wrench. Look at it this ways. With a 6 inch wrench at 90 degrees you have added zero length to the straight line length of the torque wrench. When the wrench is in line with the torque wrench the full 6 inches add to the length. Any angle buts you somewhere in between. So what ever the center of the nut or bolt would be draw a perpendicular line to the torque wrench. Whatever that adds in length, use that in you calculations.

Or you could grind down the socket. That might be easier since the engine is still in the car. :)

#5 Guest_Bill Putney_*

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Posted 14 November 2002 - 07:50 PM

"you could take the cam cases off and that will give easy access to all head bolts." That's a lot of work if you can accomplish the same thing by spending 20 minutes grinding down a socket that can be used an infinite number of times in the future.

And, captcu - what you describe is available commercially and is called a "crow's foot". The ones you buy are like an inch or two long business end of an open end wrench with a square hole in the "handle" nub for the torque wrench just like a regular socket. Very good point about paying attention to its orientation to keep the torque honest.

#6 Guest_ShawnW_*

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Posted 14 November 2002 - 08:02 PM

Sticky topic, please archive in 10 days.

#7 Guest_baccaruda_*

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Posted 14 November 2002 - 10:01 PM

true, bill. plus you don't have to replace the gaskets. i've only taken heads off (at the yard) so far so I've not had to worry about reassembly yet :D

#8 Guest_soobiedoobie_*

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Posted 15 November 2002 - 02:25 PM

thanks guys. ive got a couple of options to try this weekend.

#9 Guest_Hondasucks_*

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Posted 17 November 2002 - 02:47 AM

there IS a tool available from Subaru to do this task, dont' have part # or cost, but I've seen a pic of it, it kinda looks like a 3/8" extension, but with a shallow socket on the end to clear the rockers. I need to get one! That and a valve adjusting tool, my GL-10 is tapping like a mofo, but with the AC and PS, it's too hard to get in there with two wrenches and a feeler gauge.

#10 Guest_tregare_*

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Posted 17 November 2002 - 10:35 PM

Good luck on getting that tool :(

At least here in the seattle area all the soob dealers (i've asked) inform me that they do not and will not order tools for customers, and they give me the phone number for the company that tTHEY buy the tools at...

Guess What... THAT company only sells to Soob dealers and tells me that if I want to order a tool, I have to do so through the dealer....

wonderful circle, eh?

#11 Guest_captcu_*

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Posted 18 November 2002 - 02:32 PM

Bill, in this case I'm pretty certain a crows foot wont work because of the extra meat on the head of an open faced wrench. It was extremely tight just getting a box end on it. I even bent the head of the wrench to get a little better angle. Even so you could only turn it a tiny bit each time. It was a pain with the engine outside the car. I don't know with the engine still in. Might not be to bad for soobiedoobie since he is only checking it and not likely to go through the 3 levels of retorquing. If I had it all to do over and the special tool was available and reasonable, I would buy it. However my guess is that what I did was similar to why you ground down a socket. Subaru parts dept. closed at noon on Saturday or doesn't have it and the job HAS to be done this weekend. ;) That and I had already gotten started before I realized it. Special tool? I don't need no stinkin special tool.

#12 Guest_Bill Putney_*

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Posted 22 November 2002 - 05:47 AM

Captcu - I see what you mean. I'm thinking now that you used the box end of the wrench - I didn't catch that before - I was thinking, when you said "flat wrench", that you were meaning the open end end.

#13 Guest_Bill Putney_*

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Posted 22 November 2002 - 06:12 AM

Here are some details on making the shorty socket (comments after the photos).

Overall dimensions of original unaltered Craftsman 17mm 3/8" drive socket (sketch provided by Skip):
<img src="http://images.fotki.com/v11/photos/4/42816/136782/skipsdrawingoforiginal-vi.jpg"/>

Finished length dimensions (see comments):
<img src="http://images.fotki.com/v11/photos/4/42816/136782/Dimensionedcropped-vi.jpg"/>

View of bolt head engagement end of finished socket:
<img src="http://images.fotki.com/v11/photos/4/42816/136782/Boltend-vi.jpg"/>

View of ratchet/extension engagement end of finished socket:
<img src="http://images.fotki.com/v11/photos/4/42816/136782/Ratchetend-vi.jpg"/>

Thanks, Skip, for the sketch (he happened to have an unaltered Craftsman socket in his arsenal of tools and gen'ed up the sketch).

My original instructions talked about grinding the length on both ends, but upon seeing the tool again after a few years (I made it and used it for the last time around '94), I realize that it had been machined (turned on a lathe using a parting tool probably). I must've given it to an obliging machinist where I was working at the time and told him what I wanted. Grinding would work for the DIY'er.

I don't have enough info. to tell you how much metal to remove from each end, but, in my finished socket, I measure 1/4" of bolt head engagement depth (plenty for most of the actual head bolt head height of around 0.289" measured by Skip), and just shy of 1/4" depth of the ratchet engagement square hole (overall finished socket length is actually just shy of 1/2"). The text stampings on the side of the socket shown in my first photo provide some visual clues.

Seeing it again also sparked my memory that there were some minor complications with the ratchet end and the ball detents. Trying to reconstruct that history in my mind, I believe that the ball detent recesses mostly disappeared from the shortening operation. Upon bringing that to the machinist's attention, his solution was to use a ball end mill to put detents back in. I now faintly recollect that, because the extensions stick out a bit beyond the balls, and therefore would not let the bolt head bottom in the other end of the socket if the extension was fully inserted, that I had the choice of the socket not engaging the ball detents of the extension, or only partially engaging the bolt head height. As a result, there was some frustration of the socket falling off the extension every few seconds during the head bolt re-torqueing effort.

I see two possible solutions, and both involve dedicating an extension to this tool:
1. Grind the tip of the extension back close to the edge of the detent balls, or
2. Weld the extension to the socket.

Just be aware that extension length is not totally arbitrary, especially if you are re-torqueing the heads with the engine in place. Method 1 would be my choice, at least until I knew for sure the necessary extension length. It might be the better choice overall anyway (gives some flexibility). Unfortunately, most DIY'ers would not be able to ball end mill the detents in without taking it to a local machine shop.

SO - What would my 2nd gen. shorty socket look like? There would be 1/16" more metal removed from the bolt head end (so there would be that much less bolt head engagement length), and there would be 1/8" less metal removed from the ratchet end. The all-around chamfer angle would be twice as deep. Results: The 1/2" overall length (see first photo) would be 9/16", and the 7/16" dimension would stay the same. Hopefully, that would keep the original ball detent recesses intact, and still fit with the available clearances in the head with cams installed.

(Thanks again, Skip, for your help and encouragement!)

#14 Guest_Bill Putney_*

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Posted 22 November 2002 - 12:46 PM

Here is a drawing of my proposed 2nd generation head bolt special tool. Note that it is only based on experience with the first one. What the detent ball recesses look like is only a guess on my part since I don't have an unmodified socket to look at. Hopefully they would still be intact as shown.

Some other games could be played with having a more complex shape around the square hole to assure that the detents stay intact while giving needed clearance for the camshaft.

<img src="http://images.fotki.com/v11/photos/4/42816/136782/Shortysocket-vi.jpg"/>

#15 Guest_captcu_*

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Posted 26 November 2002 - 03:01 PM

Nicely done Bill. My fix was not as purdy. :lol: I did a little checking and as someone had mentioned the subaru tool is not readily available. They told me 4 to 6 weeks and the guy didn't seem to sure about that at all. Surprised this issue hasn't popped up before. Then again it probably has.

#16 thedoctor


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Posted 22 April 2012 - 07:22 PM

I can't see the images and I really want to know how to make a special tool. Do you suppose I could fashion a connection between a ratchet box wrench and a torque wrench? Perhaps one that would fit through the other end of the wrench.

#17 GeneralDisorder


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Posted 22 April 2012 - 07:52 PM

You don't need the tool. Put sockets under the bolts that go through the rockers arms and tighten them as normal. Then pull out only the ones for the rocker assembly, install it, and torque them back down.


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