Welcome to 911UK
The only place for Porsche, 911uk is the definitive enthusiast and resource site for the Porsche 911.
Registration is fast, simple and absolutely free, so join up today for full access to the site and benefit from latest member offers.

Porsche Classifieds
Sell Your Porsche on 911uk
Create a Free Classified Advert
Search Ads
Classified Adverts FAQ
Trade Classified Information
Buyer & Seller Fraud Protection
Consumer Rights Act
Pre Purchase Inspection (PPI)
Porsche Car Sourcing
Porsche Cars Wanted
Official Porsche Centre Reviews
Model
Stock
Porsche 911
992 : 2019- 0
991 : 2011- 24
997 : 2004- 60
996 : 1997-2005 30
993 : 1993-1998 2
964 : 1989-1993 0
Carrera 3.2 : 1983-1989 2
Carrera SC : 1977-1983 3
930 Turbo : 1975-1989 1
Early 911 : 1964-1977 1
Porsche Other Models
Classic : 1950-1965 0
Boxster : 1997- 27
Cayman : 2005- 22
Cayenne : 2003- 7
Macan : 2014- 5
Panamera : 2009- 0
912-914-924-928-944-968 0
959 - CarreraGT - RaceCar 0
Car Parts For Sale & Wanted
Other Items For Sale & Wanted
Wheels Tyres For Sale & Wanted
Number Plates For Sale Wanted

Porsche Services
Porsche Body Shop Repair
Paint Protection & Wrapping
Porsche Classic Insurance
Porsche Classic Parts
Porsche Classic Restoration
Porsche Design Collection
Porsche Engine Gearbox Rebuild
Porsche Heritage & History
Porsche News
Porsche Picture Gallery
Win a New Porsche 911

Porsche Parts
Body Parts, Body Styling
Brakes, Clearance
Electrical, Exhausts
Engine Cooling, Engine Electrical
Engine Rebuild, Heating Cooling
Interior Incar, Lighting
Rubber Seals, Service Parts
Steering, Suspension
Transmission, Workshop Tools
Early 911, 911 - 930, 928 - 968
964 - 993, 996 - 997, Boxster
Cayman, Cayenne, Panamera

Porsche Model Range
911 [992] 2018-Current
Porsche 911 [992]
911 [991] 2011-2019
Porsche 911 [991]
911 [997] 2004-2012
Porsche 911 [997]
911 [GT] GT1-GT2-GT3
Porsche 911 [GT]
911 [996] 1997-2005
Porsche 911 [996]
911 [993] 1993-1998
Porsche 911 [993]
911 [RS] RS-RSR
Porsche 911 [RS]
911 [964] 1989-1993
Porsche 911 [964]
911 3.2 1983-1989
Porsche 911 3.2 Carrera
911 SC 1977-1983
Porsche 911 SC
911 [Early] 1964-1977
Porsche 911 [Early]
Boxster & Cayman
Porsche Boxster & Cayman
Cayenne & Panamera
Porsche Cayenne & Panamera

911uk Site Partners

Post new topic   Reply to topic
Author Message
NedHan79
Hockenheim


Joined: 08 Nov 2018
Posts: 713



PostPosted: Wed Jan 08, 2020 11:08 pm    Post subject: Helicoil help needed Reply with quote

Started to build the front of the car back up and in the process I have stripped a few threads. One being the top caliper bolt on the drivers side and the others are 2 of the front anti roll bar bolts into the subframe. I know the hub is a known one for stripped threads and I’m guessing the alloy subframe is just the same.

I have some tap and dies there which I’ve used on basic jobs but I’ve never used helicoils. Is it simply drill out to a lager hole, tap it for the larger helicoil and screw it in?
Also, does anyone have any idea what size of items I need to buy? I think they are both m12 but tbh I didn’t really look.

As usual all help very welcome
_________________
#modified996mk1
 
  
View user's profile Send private message
   
Marky911
Sepang


Joined: 04 Jun 2009
Posts: 2829



PostPosted: Wed Jan 08, 2020 11:39 pm    Post subject: Reply with quote

Hi Ned,

Yeah that’s pretty much it.
Larger drill to drill out old hole then a helicoil is like a stiffly wound spring of metal that forms the new thread. There’s a tang in the bottom you use to wind it into the new hole once the hole is tapped with the correct helicoil tap. Once the insert is wound down to the required depth you use a small punch to break the tang off the bottom so your bolt won’t bottom out on it.

A helicoil kit will usually include some inserts, the tap, insert tool and sometimes the drill.




You also have timeserts which are solid tubes of metal featuring the correct original thread on the ID (internal diameter) and a larger thread on the OD (outer diameter).

Martin covered these along with another of his excellent “how to” videos a little while back.

Timeserts are stronger but helicoils are fine when used properly. Some parts we produce at work ask for helicoils from day one. Mainly Ali parts where the threads won’t stand up to repeated use.

Biggest thing to get right is the angle of your drill for the insert. Go in incorrectly, even a few degrees and whatever you then bolt upto the helicoiled part will not sit flush. Not so bad on static things (although not ideal obviously) but do it with your hub/upright and every time you brake your caliper will flex.
My mate Craig on here had an annoying creak when braking hard in his C2. Some bozo had done exactly that.
He had to source a new hub carrier. nooo

PS I can’t help with bolt sizes off the top of my head. I’m lucky in that I can take them into work and use the female thread gauges to tell me what it is.

You can measure the width obviously but the pitch is harder as there isn’t much difference between 1.5 and 1.75 etc. Wink
It’s still totally doable with a vernier though.

Good luck. Thumb
 
  
View user's profile Send private message
   
kurlykris
Magny-Cours


Joined: 30 Jun 2014
Posts: 2656
Location: Warwickshire


PostPosted: Wed Jan 08, 2020 11:42 pm    Post subject: Reply with quote

Caliper bolts are M12 x1.5 pitch.

Yes you just drill and tap a larger diameter hole then screw the helicoil in with the insertion tool and when it gets to the bottom of the hole the tang at the end that you screw it in with snaps off Thumb
_________________
1998 996.1 C2 3.4 with "Aerokit Cup"
2006 987.1 Boxster S 3.2 sport chrono
2010 Mercedes E350 AMG Sport

 
  
View user's profile Send private message
   
NedHan79
Hockenheim


Joined: 08 Nov 2018
Posts: 713



PostPosted: Thu Jan 09, 2020 6:34 am    Post subject: Reply with quote

Sounds good guys. Thanks. The only thing I need to figure out now is the size of the thread Question
_________________
#modified996mk1
 
  
View user's profile Send private message
   
saxon46
Monza


Joined: 16 Mar 2015
Posts: 194
Location: south wales boy bach


PostPosted: Thu Jan 09, 2020 8:32 am    Post subject: Reply with quote

Get on youtube, plenty of stuff on there.... thumbsup
_________________
MARK-english lad in wales....where men are men and sheep are scared


84 carrera 3.2
And a couple of old bikes
 
  
View user's profile Send private message
   
maldren
Suzuka


Joined: 07 Oct 2016
Posts: 1239



PostPosted: Thu Jan 09, 2020 8:35 am    Post subject: Reply with quote

Helicoils are often too short, make sure that you get them the correct length for what you need.
_________________
Mike
2003 996.2 C2 Coupe Arctic Silver
 
  
View user's profile Send private message
   
Martin996RSR
Nürburgring


Joined: 08 Dec 2016
Posts: 472



PostPosted: Thu Jan 09, 2020 9:18 am    Post subject: Reply with quote

I've done a few helicoils in my time. Make sure you get a kit that comes with the correctly oversized drill bits. Also, by far the most vital aspect of a successful helicoil is accurately drilling out the hole. Use a drill press/pillar drill and secure the part on the bed properly and accurately, or if on the car, make a drill guide from whatever scrap you have available. The tapping of the hole and inserting the coil are the easy parts.
 
  
View user's profile Send private message
   
NedHan79
Hockenheim


Joined: 08 Nov 2018
Posts: 713



PostPosted: Thu Jan 09, 2020 10:24 am    Post subject: Reply with quote

Ordered a kit on eBay this morning so I’ll see how I get on.

Thanks for the heads up
_________________
#modified996mk1
 
  
View user's profile Send private message
   
Alex
Le Mans
Le Mans


Joined: 06 Mar 2014
Posts: 17349
Location: The Ribble Valley, Lancashire

2000 Porsche 996 Carrera 4

PostPosted: Thu Jan 09, 2020 5:00 pm    Post subject: Reply with quote

I wouldn't be too keen on helicoils holding my calipers on.
_________________
2000 Manual 996 C4 Arctic Silver Convertible


 
  
View user's profile Send private message
   
NedHan79
Hockenheim


Joined: 08 Nov 2018
Posts: 713



PostPosted: Fri Jan 10, 2020 6:30 am    Post subject: Reply with quote

For anyone that needs to know, the front arb bolts are m10x1.5.
_________________
#modified996mk1
 
  
View user's profile Send private message
   
Display posts from previous:   
Post new topic   Reply to topic   All times are GMT - 12 Hours
Page 1 of 1

 
Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You can attach files in this forum
You can download files in this forum
You cannot post calendar events in this forum