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Retapping thread question
Notch Nut - September 21st, 2008 at 06:37 PM

While I was changing my front brake cylinder, the thread on the bolts holding part of the steering assebly have sheared. The thread inside the wheel hub that the bolt is supposed to screw onto is stuffed completely.

Does anyone know what the correct thread tapper size is so I can get one tommorow to fix it! (both the thread on the bolt and for the thread that the bolt screws into.

I have put arrows on the pics to show where the bolts are supposed to go if no sense can be made from my description above.
Cheers - Adam:blush:
http://i84.photobucket.com/albums/k35/notch_nut/BrakesFrontDrivers04_resize.jpg
http://i84.photobucket.com/albums/k35/notch_nut/BrakesFrontDrivers03_resize.jpg
http://i84.photobucket.com/albums/k35/notch_nut/BrakesFrontDrivers01_resize.jpg


trickysimon - September 21st, 2008 at 06:44 PM

Always somthing, welcome to the club :smilegrin:
Simon


LUFTMEISTER - September 21st, 2008 at 06:59 PM

get another 2nd hand one with good threads. Would not put an insert on a steering part!


greedy53 - September 21st, 2008 at 07:08 PM

you can drill it out to the next size and drop another bigger bolt in it's the easyest and best never have to touch it again and put a dab of grease on the thread when re assembling
most hardware stores will have a drill and tap and bolt :no:


VWCOOL - September 21st, 2008 at 08:37 PM

Maybe install a longer bolt and a nut... but much betterer to get another component


Notch Nut - September 21st, 2008 at 09:08 PM

Quote:
Originally posted by VWCOOL
Maybe install a longer bolt and a nut... but much betterer to get another component

The problem is that the steering arm is unthreaded, the bolt screws into the backing plate (threaded) to the brake drum (which is all sheared and has done the damage to the bolt thread), the brake cylinder holes are unthreaded and a nut then holds the rest in place.

The above makes little sense.... (now for laymans terms that I can understand)
The bolt travels through all of these holes in this order
- Steering arm (unthreaded)
- Backing plate (threaded)
- Brake cylinder (unthreaded)
- Securing nut.

What I am hearing is that it would be better to drill the baking plate thread off to prevent further shearing of the thread and rely on the nut at the other end to hold it all in place???
Is this really a good way to go??

Wouldn't the purpose of having the backing plate threaded be for an extra fail safe in case the nut is loose?
Relying solely on the nut staying tight doesn't sound too safe. (even though it is just one hole that is stuffed and needs re tapping.)
- Adam


Notch Nut - September 21st, 2008 at 09:19 PM

Quote:
Originally posted by trickysimon
Always somthing, welcome to the club :smilegrin:
Simon


Yeah, aint that the truth!!

I moved my wagen from "visitors parking" as the neighbours were getting shitty for me having an unregesteed car parked there (along with my other neighbour who was doing the same!:blush:). Apparently, it was "devaluing" the estate and making it harder for the neighbour selling his house to fleece potential buyers by overstating the real worth of his property.
I got the ol girl going again, spent the entire weekend removing the old rusty muffler and getting it running nice. Thought I'd fix the front brakes and now I have an unregestered car in my driveway on bricks blocking my other drivable car from leaving the garage!
These dubs are makin me crazy:crazy:
- Adam


leweydafly - September 22nd, 2008 at 08:28 AM

the thing with drilling it out and putting a bigger bolt it is that you have to drill right through. steering arm, hub, backing plate and brake cylinder. these parts are engineered specificaly for that size and strength bolt. you start drilling things out you lose strength in a critical area. the bolt holds the steering arm to the hub and the bolt continues though with the nut to secure the cylinder and the backing plate. IMO you are better off using a helicoil to re thred the hub and use the original size bolt. helicoils over the years have been show to give the same if not more strenght to the hole when used. if you do go the 'cheaper' easier route of a longer bolt or bigger bolt make sure its the same tensile strength as the old one. last thing you want is a brake or steering part to fail.

cheers

mick:ninja:


byronmcmanus59 - September 22nd, 2008 at 10:35 AM

AGREED! go the helicoil.. although you may be a bit scared of the price.. there not cheap.


matberry - September 22nd, 2008 at 11:15 AM

Go the replacement parts.


Notch Nut - September 22nd, 2008 at 11:54 AM

I definetly need some replacement bolts so Nick A Part is looking pretty convenient. I think the bolt(s) should be the same size of a drum brake beetle if there aren't any drum brake type 3's (which there usually arent).
At the moment, my main priority is to get the thing assembled so it is able to have the wheel fitted so the car can be moved (it is currently unregistered and far from RWC so a quick fix is better than having it blocking my driveway!). Hopefully the replacement brake cylinder works it's job properly and the brakes don't jam in the locked position.

I am thinking it easiest to use a round file and file away any remaining thread from the inner plate and re-tap the thread so it doesn't damage the replacement bolts. Failing that, a helicoil or replacement backing plate is the next option when and if the car ever gets back on the road. It is only one hole that is stuffed so it should suffice for a temporary fix on an undriven car.

Thanks for the input guys:cool:
- Adam


leweydafly - September 22nd, 2008 at 09:49 PM

helicoils mightn't be cheap but if you buy the sets they last for ages. i've got metric 6, 8, 10 and 12 kits i bought years ago. amazing how often they've come in handy

cheers

mick:ninja:


Notch Nut - September 22nd, 2008 at 10:15 PM

I'm thinkin that because the car isn't moveable or registered it might be easier to get a backing plate and bolts to suit at the moment.:rolleyes:


Notch Nut - September 23rd, 2008 at 06:52 PM

Problem solved. The sheared bolts were imperial not metric.:rolleyes:
Thread has been re tapped to drum backing plate and the correct bolts thread in just dandy.:smirk: