Cross Threaded Plugs?? Help

[Weeksz]

Ok I'm in a bit of a panic right now. I was just doing some cleaning on my head, about to reinstall and I noticed that cylinder #3 spark plug threads appear to be cross threaded! It was running ok before this rebuild (minus oil leak/burn) and I don't remember having difficulty tightening any of these plugs in the past. What are my options here? I just installed my valve seals, lapped my valves and had about $200 of work done at the machine shop extracting some snapped bolts....

I have a really nice set of Mac Tools tap and dye(sp?) set that I'm harrowing from a friend to chase and clean my threads. So I guess maybe I could rethread it? So like I said before.. What are my options?

Thanks a lot for any advice.

 

[Steve]

Grease up the tap to catch any chips, thread carefully.

.

 

[chuck hahn]

NAPA SAVE-A-THREAD KIT. Put the steel sleeves in and be done with it..and its even more convenient seeing the head is already off. Use the longest insert. And keep the packaging to order new inserts if needed later.


http://www.nationaltoolwarehouse.co...1o3kIn5phdBrRrFpPA2TpoGyCk-KQwoHrmmXWooTw_wcB

 

[Weeksz]

Just to be sure. 14 x 1.25 IS the thread of my plugs correct? (81 gs750L)

 

[bwringer]

Just to be sure. 14 x 1.25 IS the thread of my plugs correct? (81 gs750L)

No. D8EA plugs are 12mm X 1.25mm thread.

The eight-valve engines take a different plug (B8ES) that has a 14mm X1.25mm thread.

 

[Weeksz]

http://www.nationaltoolwarehouse.co...-Plug-Size-Series-Metric-12-125mm-P14322.aspx

$119.00??! How is the 14 x 1.25 $25?

 

[Scratcher09]

I started to cross thread a plug and here is how I fixed it easily without removing the head.

http://www.dotheton.com/forum/index.php?topic=59700.0

 

[Brendan W]

Not much use now but for the future I always start plugs with a foot of garden hose. It's much easier to see whats going on and place the plug bang on the hole - right, you really did clean the seat in there - and you're never going to cross a thread. It also helps removing them to use it for the last few threads - stops them falling out of sockets and rattling around the fins on pots 2 & 3 of 4 pot mills.

 

[Weeksz]

That'ts a good suggestion. Although I don't think that I was the culprit behind the cross threading. They never went in forcefully the few times I had them out before I started my rebuild. I guess it could have been me but I dk.. Just called the machine shop and they said $35 so i'm just gonna go with that.

 

[Grimly]

http://www.nationaltoolwarehouse.co...-Plug-Size-Series-Metric-12-125mm-P14322.aspx

$119.00??! How is the 14 x 1.25 $25?

Lower demand - millions of M14 plug holes out there and relatively few M12 - possibly higher production cost, but certainly more competition on price. And because they can, of course.
The ordinary M12 x 1.25 insert kit is more of a competitive price
but a fixed length of insert (18mm) with it.
http://www.nationaltoolwarehouse.co...-Kit-Fine-Metric-M12-x-125-x-18mm-P14328.aspx

 

[Johno]

Try one of these first:

http://www.amazon.com/not-listed-TX321-Thread-Chaser/dp/B000AF2XFU

 

[Scratcher09]

Problem with thread chaser is that it is only safe to use with the with the head off the motor.

 

[Johno]

Problem with thread chaser is that it is only safe to use with the with the head off the motor.

News to me! I've only used mine with the engine intact.:tears_of_joy: