Car mechanics – helllpp!

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  • Car mechanics – helllpp!
  • Premier Icon richmars
    Subscriber

    How long is the threaded hole?
    Can you see how damaged to thread is? Any chance of cleaning the damaged thread? If you can, you may be able to get the bolt past the damage to some good thread, but depends how deep the hole is.
    Further bodge would be to drill out the tapped hole (all the way) and use a longer bolt with a nut on the other side.

    wobbliscott
    Member

    You can get a tap and run it through, sounds like I you may have caused damage to the first few threads.

    If it’s a through hole you could run the bolt in from the other side without the shock in position, just to re-form the thread.

    Premier Icon matt_outandabout
    Subscriber

    It is a 3-4″ long bolt, m12 or so.
    Cannot drill and nut as it is disc mount, hub carrier, suspension tie all in one etc
    The top hole on this pic.

    boblo
    Member

    If the bolt is 4″ long, how deep is the threaded hole? If it’s also 4″, 4 threads isn’t going to make much difference. Clean with a tap and start carefully.

    Caveat, I’m not a mechanic and closely fit the STW stereotype ๐Ÿ™‚

    Premier Icon molgrips
    Subscriber

    Sometimes you can find the original thread, so try keeping it straight and screwing in. Tryremoving the whole thing from the car.

    Premier Icon matt_outandabout
    Subscriber

    Bolt is 4″ long, but only 2″ in in hole as rest is the end of the shock absorber.

    trail_rat
    Member

    Get a blind hole/bottom tap and tap holder for the thread size

    Only do molgrips idea if you want to completely spacker it thats nothin more than luck. – although for odd sizes i have made my own tap out of bolt + bench grinder and saved it that way.

    mcmoonter
    Member

    If you don’t have a tap to hand, you might be able to try this.

    [video]http://www.youtube.com/watch?v=iuSk53cMsFk&feature=youtube_gdata_player[/video]

    sugdenr
    Member

    If the threads on the bolt are damaged too then you will need to fix that also. If the bolt is OK and the hole is only a bit damaged molgrips technique might work, but it usually only works on ally not cast iron. A bolt thread gets max strength with only a few threads so unlikely to be a problem once you fix, its shear force on the bolts, so as long as it tightens up OK you are absolutely fine.
    If you haven’t got/cant get a tap and die, try cleaning up the bolt with a fine file and try molgrips idea carefully, dip in oil first, maybe just maybe.

    Premier Icon matt_outandabout
    Subscriber

    ^mcmoont I think that is what I need – if that does not work, then it is goosed and I will need a new hub carrier… ๐Ÿ™

    Premier Icon matt_outandabout
    Subscriber

    So I was changing the rear shock absorbers on my Touran today.
    The last bolt was to mount the shock at the bottom, into the rear hub / carrier.
    The bolt has started to cross-thread (maybe first 4 threads) – I stopped as soon as I realised. The hole is a tapped one, into the main hub.
    Is there *anything* I can do, other than go find a new hub carrier and bolts etc..?
    (and grrr at more VW duff design, as the bolt is too long to easily get in or out past springs…)

    trail_rat
    Member

    Mcmoonter has it – thats sinilar to what i do when i dont have a tap.

    mcmoonter
    Member

    Is it your only car and do you need it back on the road for Monday? I have got a tap set but I’m probably about fifty miles away. It should be salvable. Failing that, you should be able to get a tap from Halfords on a Sunday.

    Inbred456
    Member

    If you try and re tap out the hole try and use a 1st tapered tap so it doesn’t follow the knackered first few threads. If it does the hub will be scrap. You really need a 1st 2nd then plug tap. I would be surprised if halfords has one of those.I would drill out the first few knackered threads, if there is only 4 cross threaded threads I wouldn’t worry.

    willej
    Member

    If you can’t save the thread as described above then you may be able to helicoil it?

    Inbred456
    Member

    Not a tapered thread but a tap with a large lead in to get past the damage. Any engineering shop would be able to re tap it or fit a M12 helicoil.

    trail_rat
    Member

    Didnt see it was 2 inch deep. Taper tap for sure ! Youll probably just nesd the taper tap to save it tbh if only the forst threads facked.

    pacerc200
    Member

    I’m failing to see how you trying to carry out a job incorrectly and stripping threads is a duff vw design.
    Take the outer spring pan bolt out, remove spring, flex pan down and you will have straight access to the bolt, start the bottom bolt first make sure it looks to be straight and you might just catch an original thread.

    You have to be good/lucky to get it right with the spring in place. Wishing you good luck.

    Premier Icon Trekster
    Subscriber

    Any tool hire shops around?
    Tap hole as others have said, use cutting fluid if possible or oil to lube tap. If doing it yourself make sure you work the tap in using small turns back and forth, back and forth. Same with die, don’t be tempted to screw all the way in a oner… It may jam and break!!!
    Die to clean up bolt = all sorted ๐Ÿ˜†
    Standard fix.
    Would not be too keen to use the heli coil idea

    Premier Icon matt_outandabout
    Subscriber

    Cheers all.
    pacerc200 – I tried removing that bottom member / pan, however every bolt is seized tight on both sides. On the other side (that went really simply), the bolt I am referring to I had to soak in release spray, then use a jack to lift end of spanner – it actually lifted car up off the stands before releasing…
    Starting to see why all the garages wanted ยฃ400+ for the job ๐Ÿ™

    Premier Icon matt_outandabout
    Subscriber

    Any tool hire shops around?

    Not that are open on Sunday. ๐Ÿ™

    trail_rat
    Member

    First rule of home mechanics.

    3 ft long half inch drive breaker bar and face drive sockets.

    Spanners wont shift anything thats been in there for a few years on our roads and multi point heads on ring spanners round bolts for fun ( based on my experiance with 26 year old land rover and 14 year old frontera.)

    Premier Icon geoffj
    Subscriber

    Matt – The Scrwfix in Stirling have a couple of tap and die sets in e.g.

    http://www.screwfix.com/p/carbon-steel-tap-die-set-51-piece-set/11449#

    They are open 10-4 tomorrow here

    http://www.screwfix.com/jsp/tradeCounter/tradeCounterDetailsPage.jsp?id=4000002

    trail_rat
    Member

    Be insanely careful with carbon steel taps

    No jerking at all and only small advances.

    If you snap that tap in there you will cry.

    Premier Icon matt_outandabout
    Subscriber

    3 ft long half inch drive breaker bar and face drive sockets.

    That is part of the problem – to get a socket in you need to dissemble the hub carrier from the suspension – but a socket wont fit in the gab between hub carrier and other suspension bits. :/

    Premier Icon matt_outandabout
    Subscriber

    At that cost, I would be better to buy a new hub at garage, as chances of c*cking up are high with me it seems..

    Premier Icon geoffj
    Subscriber

    At that cost, I would be better to buy a new hub at garage,

    You must know some cheap garages. ๐Ÿ™‚

    Inbred456
    Member

    Nothing wrong with helicoils but they can be tricky to insert. A first tap should be fine. Don’t use any oil or cutting fluid you don’t need it for cleaning the thread out. It may also affect the bolt torque and you don’t want that bolt loosening off. If you have to, put some copper grease on the shoulder of the bolt as that is where it will stick.You really don’t need a new hub it will be fine, trust me I have repaired far worse and never had a problem. You are to be commended for having a go. The whole exercise is to save money.

    Premier Icon takisawa2
    Subscriber

    4 threads of a M12 is 7mm out of the 50mm you reckon is in there. Just get a 12mm drill & take the first threads out, a few mm at a time.
    And it’s a big drill, you don’t want the thing spinning at max rpm.
    Hold the drill nice & steady, & in line with the hole.
    You could grind down a bolt so it’s a 90deg quadrant, & pop it down the hole, engage the thread & try working it outwards. Tricky but it’s worked before.

    neilb67
    Member

    Matt, If it the same as the Golf/Scirocco its a metric fine thread. Ive crossed threaded these loads of times on our race cars. When mounted in the car the angle that it is tapped is a lot steeper than you think. The proper bolt has a lead on the end to locate it and make it easier to start. I know it sounds brutal but we just get a bolt with a longer lead and drill out the first few threads. Where are you based..?

    Premier Icon matt_outandabout
    Subscriber

    I am in Dunblane.
    It is at an odd angle to the casting – and yes had a lead. On the other side, i just had to jack up the suspension *slightly*, then hold the new shock compressed and in line – a bit of wiggling, a few ‘missed’ stars and away….
    Nowhere in Stirling has an M14 bolt or tap n die set, so day off tomorrow to sort it out.

    boblo
    Member

    20/20 hindsight …. That’s the trouble with home mechanicing…. A lost weekend, a days leave a a less than perfect repair. A ยฃ400 garage bill starts to look more attractive.

    Hope you get it sorted. Should be straightforward once you have the right tools.

    Premier Icon matt_outandabout
    Subscriber

    Whooooooooop. We’re done and on.
    Last attempt at clearing start of threads on hub carrier and suddenly a perfect wee coil of metal dropped out, so gave it a go with the cleaner up bolt.
    Phew, and still a good few quid saved. We did not have luxury of garage vs weekend. ..

    sharkbait
    Member

    Nice one Matt – those sort of things usually happen to me! Glad you got sorted.

    trail_rat
    Member

    Good news that matt, saves doh.

    I had to resort to the good old universal rotary spanner removing my body mount bolts today they were not for shifting at 15 years undisturbed !

    Got the oil sensor changed and the oil + filter and air filter done this morning thought ๐Ÿ™‚

Viewing 37 posts - 1 through 37 (of 37 total)

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