DiscoWeb Message Boards

Go Back   DiscoWeb Message Boards > Technical Guides and Bulletins > Projects and Tech Guides

Projects and Tech Guides A curated section for member projects and member-produced guides.

Thread Tools Display Modes
Old 06-06-2017, 08:44 AM   #1
mjbrox's Avatar
Join Date: Jun 2008
Location: Golden CO
Posts: 1,441
Default Cross threaded spark plug fix

So last week I cross threaded a park plug. Not too deep, but probably two full revolutions. As any sane person would, I freaked out. I looked at thread chases but they seemed like you could mess it up even more, and push metal shavings into the head.

So after some searching I found the

Powerbuilt 640811 14mm Back-Tap Thread Repair Tool

Basically you insert the tool into the head, expand the threads and back it out.

Even with the threads retracted you can lightly thread it in. Once reasonable deep I expanded it and then backed out. I probably did over a dozen passed. I was being extremely careful. I also kept the tool covered in grease to catch metal filings

The results were, I was able to easily thread my plug all the way down by hand before torquing it down

These don't appear to available in stores so I had to have Rover down all weekend while I waited for the tool.
mjbrox is offline   Reply With Quote
Old 06-06-2017, 11:27 AM   #2
squirt's Avatar
Join Date: Nov 2008
Location: Los Angeles
Posts: 697
Default Re: Cross threaded spark plug fix

I've used this before, bought mine from Amazon. Cyl #8 spark plug threads on a D2 were bunged up, and the spark plug was only about 2 threads in (forced/cross threaded) when I got it. Trying to chase the threads from the outside was hopeless, as they were destroyed. This thing was slick as hell, just want to reiterate that you need to grease it up to catch all the filings that come off. 3-4 graduated passes did the trick for me.

Worth every penny.
squirt is offline   Reply With Quote
Old 06-06-2017, 12:07 PM   #3
mjbrox's Avatar
Join Date: Jun 2008
Location: Golden CO
Posts: 1,441
Default Re: Cross threaded spark plug fix

Oh yea. I did 12 passes or more. I used fresh grease on every other pass
mjbrox is offline   Reply With Quote
Old 08-07-2017, 08:54 AM   #4
WaltNYC's Avatar
Join Date: Mar 2010
Location: NYC
Posts: 315
Member Trucks
Default Re: Cross threaded spark plug fix

Good stuff. Thank you for posting this. #8 cylinder can be a pain. Some spark plug sockets don't fit very well. The exhaust manifold gets in the way.
1997 Discovery I SE - 145k miles

RAVE in pdf:
Discovery I exploded parts diagrams....
WaltNYC is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Spark plug Q's msggunny Discovery - Technical Discussions 9 03-18-2011 10:45 AM
D1 Oil Around Spark Plug tedhass Discovery - Technical Discussions 1 03-14-2011 12:41 PM
LR3 spark plug MontrealRR90 LR4/LR3 - Technical Discussions 2 02-15-2011 01:33 PM
cross threaded intake bolt - need advice. knewsom Discovery - Technical Discussions 20 03-18-2010 01:06 AM
How does this spark plug look? TampaChris Discovery - Technical Discussions 8 12-16-2009 01:10 AM

» Log in
User Name Not a member yet?
Register Now!
» Today's Birthdays
jbdisco2 (55)
Yeti (43)
mainerova (37)
Powered by vBadvanced CMPS v3.2.3

All times are GMT -4. The time now is 07:54 AM.

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright 2000 - 2015, DiscoWeb.org. All rights reserved.

Garage Plus vBulletin Plugins by Drive Thru Online, Inc.