How you figure to remove this here plug?

[71CHEVYSHORTBED402]

71 C10 BBC

Got off the phone with one of our finer part guys, I'm ordering wire harnesses, and correct me if I'm wrong, but I think we came to a consensus the temperature sensor on a 71-72 BBC truck (perhaps all BBC 68-72 trucks?) is supposed to be on the LH head.

See in my case, where nothing is ever easy my temp. sensor is on the RH head. These heads came off a 68 Camaro SS. Any suggestions how to remove this plug? I haven't even tried, though I think I know what to expect Assuming it's the same as an axle plug then I have the correct Allen fitting, for what worth. Here's what I'm not going to do

Not torching it I stop at heat gun & not much of it

Not using my favorite penetrating oil acetone/tans. fluid, that can leave a mark. So WD-40, don't think it will work anyway

Bummer if I have to add wire to a new harness, I don't want a butt-connect near this truck. Maybe they'll custom that wire too

Speak of one of our better part sources, keep a guy in your prayers, he's had a time of it this last year or so, involving those around him & losses. Some of you know who I mean.

[Willys_MB]

I have the same heads. On mine I shoved a 3/8 drive socket in there and got it loose with some muscle. You can always get a replacement plug for the other side and paint it before installing it. It just needs some sealant on it to prevent leaking of coolant. It’s hard to do with it in the truck because there isn’t a lot of room there.

[Willys_MB]

Originally Posted by Willys_MB

I have the same heads. On mine I shoved a 3/8 drive socket in there and got it loose with some muscle. You can always get a replacement plug for the other side and paint it before installing it. It just needs some sealant on it to prevent leaking of coolant.

Oh... I just realized it’s a BBC. May still be a 3/8 drive, but mines a SBC

[Steeveedee]

My BBC has the temp sender in the passenger's side head. I believe the SBC had it on the driver's side.

[dmjlambert]

I was nervous about trying to take the plug out of my SBC head. It had been about 3 years since the engine was rebuilt and I was not able to get in touch with the rebuilder about whether he had the plug out during the rebuild.

I took it to a pro mechanic and let him have a shot at it. He sent me pictures as he went through the process of trying a number of things, going through ideas of impact wrench, torch to heat, easy out removal tool, drilling it out, drilling it even bigger, etc. He had to destroy it to get it out and spent a lot of time on it. He said for future reference it is better to use brass plugs, the steel plug threads rusted and made it difficult to remove.

In my case I wanted to add a temp sensor, so I have one in each head. One is for the gauge and the other one is for the warning light, which I have not connected yet but it's on my list of things to do.

[LockDoc]

-
I only have a couple of suggestions. First one is to put a short extension in it and rap on the end of it with a hammer to break the threads loose. After you do that use a 3/8 impact with about 40# pressure to turn it out. Go both ways with the impact. Second is a mini butane torch and heat it up. Yeah, you will have to touch up the paint but you won't have to go through what the guy did in the second set of pictures.....

LockDoc

[Willys_MB]

Originally Posted by LockDoc

-
I only have a couple of suggestions. First one is to put a short extension in it and rap on the end of it with a hammer to break the threads loose. After you do that use a 3/8 impact with about 40# pressure to turn it out. Go both ways with the impact. Second is a mini butane torch and heat it up. Yeah, you will have to touch up the paint but you won't have to go through what the guy did in the second set of pictures.....

LockDoc

I second this. I didn’t mention on my post that I rocked it back and forth to break the threads loose. Penetrating oil probably won’t work because it SHOULD have a sealer on it to prevent coolant leaks.

[71CHEVYSHORTBED402]

Originally Posted by Willys_MB

Oh... I just realized it’s a BBC. May still be a 3/8 drive, but mines a SBC

Yeah it's 3/8". I figure I can use the same plug should she budge & clean, agree on sealant. If it comes off like the sender did no problem, at the moment I figure not that easy. Muscle I got, comes in the form of big (*^ tools and a pipe if she needs it.

[71CHEVYSHORTBED402]

Originally Posted by Steeveedee

My BBC has the temp sender in the passenger's side head. I believe the SBC had it on the driver's side.

Well that's nice to learn. Think I've had this conversation before? I've already forgot half the stuff I used to not know........Darn it!

And post five is a deterrent

Nice suggestions Doc. I've been putting off an impact for over a year now, and it keeps coming up. May not be an issue by what Steve said.

[MAC71Cheyenne]

For what is worth, I have had better luck with the tap it first and then actually crank it to the tight side a hair first then loose... Just a thought.

[mr.mud1]

hi,this is only my 2 cents worth but i've broken one of those plugs with an impact so i'd be careful.if i'd known it was delicate as it was,perhaps i would've gone a little easier with the impact and not broken it,but i didn't go easy enough and sheared off the drive end of the plug.it should come out as long as you can get a 3/8's drive extension past the flange of the manifold in the square drive on the plug.let some penetrant work at it for a while,can't hurt but it should have sealant on it.hammer on the end of the extension,as already said.if the castings were hot tanked and i'm sure they were,maybe it's clean in the water passages but it'll come out,i'm sure.
i wouldn't be too concerned about the sealant.i use it all the time on cylinder head bolts that go into water,they always come out when we're taking engines down.good luck.you'll do fine.Greg

[57taskforce]

I would try using a 3/8 battery impact on the Lowest setting forward and back, if it doesn’t budge move it up a power setting. I’ve found you are more likely to strip the head on them by hand if they are really stuck than with an impact and light power. Smacking it with a hammer and extension as said above is a really good place to start.

I easily drill about 10-15 of these same plugs a month on the engines I build at work. It’s not hard as long as you can get a drill in there. Drill it out as large as you can without catching the threads in the block. Then use the biggest easy out you can get into the hole you drilled and gently but firmly drive it in tight before you start trying to loosen it. Normally the heat from drilling it will work to your advantage. Don’t use a small easy out what ever you do, you will regret that when it snaps off.

[71CHEVYSHORTBED402]

Well Steve I don't know. Problem is I don't see any clear shots of a RH head. Are your heads factory? I wouldn't think they'd switch heads 1970 Vs 1971, maybe they did.

Here are a few pics I found. Some are un definitive though I could be convinced the sensor is on the LH heads. It's on the LH head on my 72 Super, but I don't know the heads and not much under the hood is original anyway.

[jocko]

Given that you don't want to heat it - I'd consider using an exacto knife to cut the paint around the perimeter so that WD40 or PB-Blaster can get in there. Then spray as good amount, trying to keep as much as possible off surrounding paint - then let it sit overnight. Then I'd tap, tighten, loosen. Maybe repeat the tighten, loosen cycle if it doesn't break free at first. I'm wary of impact wrenches on stuff like this, prefer a 3/8 breaker bar, I always "think" it provides more feel and early warning to doing damage, but it could just be my imagination too.. It might sound caveman but since my 3/8 breaker bar is pretty short, I slide my hydraulic jack handle over the end of the breaker bar to get several feet of leverage - and then CAREfully apply some pressure being cognizant of not rounding out the square 3/8 with the breaker bar. None of that may be needed, a standard 3/8 breaker bar right off the bat with no other hocus pocus might work just fine too, especially since you had it apart not too long ago.

[pjmoreland]

Maybe you will get lucky and it will loosen by hand. Can't hurt to try. I removed one from my SBC head a few months ago, and although it was pretty tight, it did come loose with a socket wrench and a short extension.

[BigBird05]

If it is so stuck that regular force will not break it free then you will probably break off any 3/8 tool that has a socket release ball in it. Buy or make a removal tool. 3/8 bar stock welded into a 1/2 drive socket. I have broken 3/8 drive ratchets on engine plugs that were installed at the factory with there impact guns.

[ChevyRacefan]

Go grab your wifes long candle, Heat the plug, touch candle to the threads , allow it to wick in to the threads, remove. Easy peazy

[Steeveedee]

Originally Posted by 71CHEVYSHORTBED402

Well Steve I don't know. Problem is I don't see any clear shots of a RH head. Are your heads factory? I wouldn't think they'd switch heads 1970 Vs 1971, maybe they did.

Here are a few pics I found. Some are un definitive though I could be convinced the sensor is on the LH heads. It's on the LH head on my 72 Super, but I don't know the heads and not much under the hood is original anyway.

Well, then. The engine was out once for a rebuild, so I guess it's possible that the heads were put on opposite sides when it was reassembled. The wire for the sensor looks factory, and I don't want to look into the cowl harness to see if there is a splice. If it was originally on the driver's side, that wire would be way too long.

[71CHEVYSHORTBED402]

Originally Posted by Steeveedee

Well, then. The engine was out once for a rebuild, so I guess it's possible that the heads were put on opposite sides when it was reassembled. The wire for the sensor looks factory, and I don't want to look into the cowl harness to see if there is a splice. If it was originally on the driver's side, that wire would be way too long.

Good point, I forgot heads can be on either side. I was thinking last night I need to pull down the harness. I'll do that before attempting something I'm sorry for.


Thanks for all the suggestions above.

Well look what's on my sender wire. Pretty sure it's 87 feet long. For all I know I tapped that when the block was R & R in 93. Must be a roll of tape on the end too

[BigBird05]

Does the BBC have the same TSC as the SBC? The tSC uses a temp sender from the pass side to control it.

[71CHEVYSHORTBED402]

Originally Posted by BigBird05

Does the BBC have the same TSC as the SBC? The tSC uses a temp sender from the pass side to control it.

Good question, I don't know why they'd differ.

My TCS wiring was incomplete, one because a wire was cut. May be the same color wire as the temp. gauge too, not sure. You may have solved the mystery, which is this wire, pictured.

The harness with the temp. gauge for this 71 402 includes the brake proportioning valve, starter & coil, and one wire for TCS. The TCS wire is maybe 18" long, so it plugs into the TCS assembly at firewall & the TCS sensor wire you speak of would follow at some config.

[kwmech]

Are you trying to hook up the TCS and make it function again? All it does is eliminate vacuum to the dist until you are in high gear. It was supposed to be an early NOx thing that didn't last very long 'cuz it really didn't work all that well

[Steeveedee]

Originally Posted by BigBird05

Does the BBC have the same TSC as the SBC? The tSC uses a temp sender from the pass side to control it.

BBC avoided the Transmission Controlled Spark (TCS) system by cubic inches. Are we talking about the same thing?

TCS in those days relied on a thermostatic switch in the manifold or thermostat housing. Once engine coolant temp was at a preset level and the trans was in high gear, vacuum advance was available.

[71CHEVYSHORTBED402]

Well, I nearly tried the wax trick, but became immediately impatient with the area, so WD40 instead. Yeah cut out some paint where could reach it. I may return to wax, I thought later I could have used a spoon to deliver it.

And yes of course it's STUCK, though I haven't let the oil sit long. Gave it the best leverage I had to keep from slipping, and that was enough to feel like I'd bust something 3/8" I have a nice 3/8" fitting (no ball), which is apparently good quality, so far. When I give her a go again I'll employ my 3/8" to 1/2" adapter, see how it goes.

After reading more of the above, time to get that impact...Long overdue anyway. Milwaukee FUEL Stubby 3/8 in. looks interesting, I imagine you can set the torque somehow.

Say Taskforce, come drill out this plug man, NM isn't too far away

[franken]

WD40 isn't penetrating oil and I have no idea why anyone has/uses it. WD means water displacement.
As for the plug, I'd put an impact on it as others have mentioned. Might try tightening and loosening alternately.