skydragon Posted February 15, 2009 Share Posted February 15, 2009 I've been replacing the front brake discs on my seven today. Did the first one ok, albiet the hub to disk bolts were VERY stiff and I could only just undo them. Disaster struck on the second wheel when I just couldn't undo one of the bolts. I got 'big Jez' round from next door and we both tried hauling on the bar... then the bolt rounded off *mad* There is no way it's coming out now. My car is a 2003 and has 4 1/4" between studs. I guess I need to buy one of these hubs ? The old disks were held on by allen (cap) head bolts and if they hadn't been I reckon I wouldn't have been able to get the first wheel sorted either (normal bolt heads would have rounded off earlier). I ordered some new bolts recently (these ones here) but they are a normal bolt head and I'd prefer to use cap head bolts. The old hub-disc bolts I removed look like this bolt here so I'm planning to use these, unless anyone can advise otherwise. 1.6 K Series EU3, 2003, ex-SuperGrad car. now Orange/Black. My website here Edited by - skydragon on 15 Feb 2009 15:39:56 Edited by - skydragon on 15 Feb 2009 15:43:30 Link to comment Share on other sites More sharing options...
elie boone Posted February 15, 2009 Share Posted February 15, 2009 Skydragon, weld a metal bar to the bolt head, the heat also will make it easy'er to undo the bolt. Link to comment Share on other sites More sharing options...
Willie. Posted February 15, 2009 Share Posted February 15, 2009 Wow...that's fairly drastic action. I wouldn't be buying a new hub just yet. I assume you have the disc/hub off the car? If not, pull it off and get it in the vice. Hit the bolt in question with a good bit of heat with an oxy-aceteylene torch. Get it from both sides as best as you can, and get it pretty good and hot. I'd do all four while I was at it. Then either bash on an old socket or weld on a bit of bar and it should go. Its very rare that heat doesn't shift a bolt. Don't heat the hub, heat the bolt. Failing that, last resort is to drill it out, or drill/grind the head off it to remove disk, then grab the bolt in the vice and work it out. Willie Link to comment Share on other sites More sharing options...
Irrelevant Posted February 15, 2009 Share Posted February 15, 2009 skydragon: Blatmail me if you need a good used 2003 hub (i.e. the old type) Link to comment Share on other sites More sharing options...
skydragon Posted February 15, 2009 Author Share Posted February 15, 2009 Thanks for the feedback, I don't have access to welding gear on hand, although I do know someone who has. I'll try to get them to try the heating methods you suggest (I'd presumed heating the hub was a no-no and might crack/weaken it). Thanks. Link to comment Share on other sites More sharing options...
F355GTS Posted February 15, 2009 Share Posted February 15, 2009 Skydragon, it's not an uncommon problem for these to round off, I use an electric file to grind the rounded head off, then you can remove the disc and normally the remaining thread comes out easily Happy to do this for you if you send it down Mark Link to comment Share on other sites More sharing options...
JimB Posted February 16, 2009 Share Posted February 16, 2009 Stupid question (not based on experience, but O-level physics):- Wouldn't heating the bolt tighten it rather than loosen it? Jim Link to comment Share on other sites More sharing options...
h_____ Posted February 16, 2009 Share Posted February 16, 2009 The heat cycle, of heat, expand, cool, contract, often cracks the corrosion that holds the 2 bits of metal together. Very effective!! Well worth trying other options before forking out for new hub. Link to comment Share on other sites More sharing options...
JimB Posted February 16, 2009 Share Posted February 16, 2009 Ah, thanks! Link to comment Share on other sites More sharing options...
h_____ Posted February 16, 2009 Share Posted February 16, 2009 I tend to undo mine using an upturned wheel, put the hug in the lugs, then stand over it with a big T bar, this gives good grip and leverage on the nut, which helps to avoid stripping it, sounds like you are past this stage though. Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted February 16, 2009 Share Posted February 16, 2009 I did the above too, but one wouldn't move. Had to resort to a cold chisel and club hammer to drive the outside edge of the rounded off thin head bolt until it started to turn, then hammered a socket on to the head to finish the job. PlusGas is quite good at penetrating into seized threads - especially if you can do it for several days with a fresh squirt each day ! Lots of CopaSlip on the new ones I fitted. Link to comment Share on other sites More sharing options...
Support Team c7trp Posted February 16, 2009 Support Team Share Posted February 16, 2009 Shouldn't the bolts be refitted with threadlock to stop 'em vibrating loose? Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted February 16, 2009 Share Posted February 16, 2009 Threadlock also acts as an anti-corrosion agent, but you only want a drop or two, or it aggravates the problem next time you want to remove them. Mine had been smothered in it by the builder, which is why I had such trouble removing them. To be honest, I don't think they will come loose. Link to comment Share on other sites More sharing options...
Area Representative Crudders Posted February 17, 2009 Area Representative Share Posted February 17, 2009 Skydragon - I'd recommend getting hold of a set of Irwin Bolt Grips - Screwfix sell them, here. These successfully removed extremely chewed up roll bar bolts from Aeroscreens' car during his rebuild. As for the bolts, the socket cap head bolts you linked to are actually machine screws as they have no shank, and as the greater sheer strength is in the shank I'd be more inclined to stick with the conventional bolts. Strength aside, there's more meat for an Irwin Bolt Grip to get its teeth into HTH, Crudders Link to comment Share on other sites More sharing options...
I.Mupferit Posted February 17, 2009 Share Posted February 17, 2009 Thanks for the link Cruds. Whilst I don't actually need them, I just couldn't resist - so placed an order. Bound to come in handy one day. 😬 Brent (aka Arfur Nayo) Lotus Elise Probably the best hair dryer in the world! 😬 Link to comment Share on other sites More sharing options...
Drumster Posted February 17, 2009 Share Posted February 17, 2009 Excellent bit of kit. Spent nearly an hour trying to remove the thin headed FIA bar bolt, getting increasingly frustrated and more and more scuffed knuckles as I rounded off the bolt head . But hey, £20 later with the bolt grips the bolt was off in a couple of minutes. Sometimes you just need the right tools for the job. Chris Alston C7CAT 1800 Supersprint R248 ....and then I jumped in Link to comment Share on other sites More sharing options...
CageyH Posted February 17, 2009 Share Posted February 17, 2009 Flank drive sockets will do the job as well. I use a 5 degree ratchet (Facom) , and six point sockets, and the problem of rounding bolts off does not happen often. They just tend to shear when attached to big expensive bits (de Dion tube 😔). Only dead fish go with the flow....! Link to comment Share on other sites More sharing options...
skydragon Posted February 17, 2009 Author Share Posted February 17, 2009 Thanks for the link, I may well get one of those for future use. Well, I gave the hub/disk to my mate and in the words of Little Britain 'The computer says No...' 😬 He tried several tried and trusted methods and just couldn't get the bolt to shift. He's a full time mechanical engineer so I'm fairly confident it was a lost cause. Fortunately I was 'down saff' yesterday getting a new Titan LSD 🥰 🥰 fitted into my diff casing by road and race transmissions, so I manged to pop into CC and get a hub replacement and some new bolts. Link to comment Share on other sites More sharing options...
Bricol Posted February 28, 2009 Share Posted February 28, 2009 I decided today that 8yrs was long enough for the discs on my car to have been on - normally I work on the "if it ain't bust .. ." principle, but seeing as we intend some Alpine blatting this year, I thought I'd replace them. So - pads outs (half worn - loads of life left - needn't have bought any new ones. . .), calipers off. Grease cap off for the first time ever - and looks dry. Hub off and it's dryer than I would have liked, but still okay bearing wise. Hub in the vise, undo disc bolts - flippin tight! But all came undone. Passenger side. . .. same again, tight! 3rd bolt . . tight . . then free . .. oh bugger . . . Yep - sheared in the hub. Seems the original loctite and corrosion combined to lock the bolt in properly! An hour of careful drilling, chiseling, and re-tapping later . . . it holds 34lbft, but I might just chicken out and helicoil it later . . . And in the process of searching for something to work with, managed to knock shiny, new, undamage, headlamp shell off the secure, won't be disturbed, place I'd hung it earlier for the paint on the filed out mounting to cure. . GRRRR. Ever thought you should just have left well alone? Bri Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted February 28, 2009 Share Posted February 28, 2009 Want to buy a pair of 7" black headlamps ?? Heading for Lancs tomorrow (very early !) Link to comment Share on other sites More sharing options...
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