Mark90 Posted July 17, 2008 Share Posted July 17, 2008 Had a few problems at the weekend with the hub bolts coming loose on my mates racer. Only on one hub, but once the problem started it got worse, as is often the case Not enough time between laps for thread lock to go off, damaged bolts (looked ok but two sheared when being done up before reaching correct torque), damaged threads in hub from running with loose bolts, etc. Replacing the bolts with new 8.8 bolts and split ring type spring washers was just about enough to get us through the rest of the event but the bolts needed tightening after each lap. Couldn't do them up too tight due to damaged threads in the (soft cheese) hub. The hubs are now going to be helicoiled and fitted with new 12.9 socket cap bolts. I've not been to impressed with split ring locking washers in this application. Loctite is ok in the garage when you've cleaned the hub etc but not ideal in the field when the bolt holes may be oily and you don't have time to allow the loctite to go off. The Nord washers mentioned in this thread I don't feel are best suited to this application due to frequency of removing the bolts, it is a landrover after all So I'm looking for suggestions on what people have found best for stopping these bolts coming undone. What works for you? Quote Link to comment Share on other sites More sharing options...
freeagent Posted July 17, 2008 Share Posted July 17, 2008 are we talking about the 5 bolts that go through the drive flange.. which are famous for working loose...? Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted July 17, 2008 Share Posted July 17, 2008 These bolts stretch Mark and once they have they'll keep coming loose Replacement is the only cure along with loctite and the correct torque. Mo Quote Link to comment Share on other sites More sharing options...
Steve 90 Posted July 17, 2008 Share Posted July 17, 2008 Mine used to come loose every time I drove the truck. Ive now fitted 12.9 cap heads and they have stayed tight for about 14 months. Quote Link to comment Share on other sites More sharing options...
mmgemini Posted July 17, 2008 Share Posted July 17, 2008 Mark One of the best ways I've used to stop bolts, ansd screws, is to drill the heads and lock wire them. When I first used my Imp on a rally, the two rear Koni shocks came loose at the top mounting. I couldn't understand why. I'd used Nylock nuts. I mentioned this to my day foreman. He told me they were getting this on the trucks. The cure they found. Ordinary nuts with ordinary flat washers under the nuts. Funnily enough after I did that no more loose shocks. mike Quote Link to comment Share on other sites More sharing options...
Mark90 Posted July 17, 2008 Author Share Posted July 17, 2008 are we talking about the 5 bolts that go through the drive flange.. which are famous for working loose...? Yep, those ones. As they are so prone to coming loose I was hoping someone had found a fix. These bolts stretch Mark and once they have they'll keep coming loose Mine used to come loose every time I drove the truck. Ive now fitted 12.9 cap heads and they have stayed tight for about 14 months. That might be the answer then. If stretching leads to them coming loose then the 12.9's shouldn't suffer from this so easily. Steve, do you do them up to standard torque or go a bit tighter with the stronger bolt? Any loctite or locking washers or do you find they stay put without? One of the best ways I've used to stop bolts, ansd screws, is to drill the heads and lock wire them. Good call. I will have to look at how easy this is with socket caps without weakening too much, don't want the cap to split open when tightening/loosening then, not a problem with the standard hex head bolts. Quote Link to comment Share on other sites More sharing options...
mmgemini Posted July 17, 2008 Share Posted July 17, 2008 Don't know Mark. I've only used ordinary high tensile bolt heads. Not that carrot 8.8 stuff I might add. You can get 12.9 in ordinary bolt heads. mike Quote Link to comment Share on other sites More sharing options...
pugwash Posted July 17, 2008 Share Posted July 17, 2008 cone washers are very very good at stopping these bolts coming undone as they put the bolt under constant sprung tension- even when undone the cone washers tend to hold the drive flange in place- last tme i needed liberal applications of tool number one to get the drive flange off. They are so effective that you actually only torque the bolts to a few Lb/Ft- 18 iirc. Not sure if they are used in the landrover world anywhere, but they are used ont he drive flanges of Landcruiser axles. Quote Link to comment Share on other sites More sharing options...
steve_d Posted July 17, 2008 Share Posted July 17, 2008 If you are not happy with Nord-lock washers then you could try http://www.schnorr.com/safetywashers.html which work very well. Where I work we have also used drilled cap head bolts and wire lock. Having suggested the above I still believe repairing the damage with helicoil then using either 8.8 or higher bolt with Loctite 270 or better still 2701 (which is oil tolerant) will do the job provided you can leave the Loctite to go off. Steve Quote Link to comment Share on other sites More sharing options...
Steve 90 Posted July 17, 2008 Share Posted July 17, 2008 Steve, do you do them up to standard torque or go a bit tighter with the stronger bolt? Any loctite or locking washers or do you find they stay put without? No idea what the torque setting would be. I put a normal length 1/2" drive ratchet on them and do them up to what feels right. I think the issue with the standard ones is that the abuse they get causes them to stretch rather than turn loose. so locktight wont help as it tends to be better when things vibrate loose which is also why I dont see any need to do them up mega tight. Its seems the 12.9 don't stretch so they seem to stay tight, My truck gets more abuse, more regularly than most and they have been perfect. Quote Link to comment Share on other sites More sharing options...
mmgemini Posted July 17, 2008 Share Posted July 17, 2008 Lie me Steve. I've no idea what torque setting. The difference is I use a Snap-On 3/8 drive ratchet to do them up on mine.... Mark. Have you thought about shake proof washers, also called star washers. I trhink the external type would be best. mike Quote Link to comment Share on other sites More sharing options...
ciderman Posted July 17, 2008 Share Posted July 17, 2008 12.9 Caps , chase and clean out the threads with solvent of some kind , Loctite 270 and as Steve said tight till they feel right . I am curently trying Nord-lock washers on the bolts only on one flange though to see if it makes a difference . Quote Link to comment Share on other sites More sharing options...
Steve 90 Posted July 17, 2008 Share Posted July 17, 2008 Lie me Steve. I've no idea what torque setting.The difference is I use a Snap-On 3/8 drive ratchet to do them up on mine.... mike Not much difference, My normal length 1/2" is only about an inch longer in the handle than my normal length 3/8" (both snap on if were name dropping :rofl: ) Quote Link to comment Share on other sites More sharing options...
mmgemini Posted July 17, 2008 Share Posted July 17, 2008 Not much difference, My normal length 1/2" is only about an inch longer in the handle than my normal length 3/8" (both snap on if were name dropping :rofl: ) Not really. Just to try to let you know the length....... No I don't own a half inch drive ratchet..... Back to washers....I had a Renault R8. Anybody old enough to remember those ?? Most of the washers looked like normal flat washers but slightly thicker. They were sort of a short come shape. I don't remember anything coming undone at the wrong time.... mike Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted July 17, 2008 Share Posted July 17, 2008 The torque for these bolts is 65nm. Mo Quote Link to comment Share on other sites More sharing options...
Mark90 Posted July 17, 2008 Author Share Posted July 17, 2008 Well it seems that the 12.9's we have just got are the way to go. Will see how we get on with those and some loctite. Maybe get some Schnorr washers for quick fix in the field when we don't have time for the loctite to go off. The torque for these bolts is 65nm Did you have to look that up? At the weekend I said I thought it was 60ish nm of the top of my head, really must get out more Quote Link to comment Share on other sites More sharing options...
Steve 90 Posted July 17, 2008 Share Posted July 17, 2008 Not really. Just to try to let you know the length....... No I don't own a half inch drive ratchet.....Back to washers....I had a Renault R8. Anybody old enough to remember those ?? Most of the washers looked like normal flat washers but slightly thicker. They were sort of a short come shape. I don't remember anything coming undone at the wrong time.... mike I was only messin! And, no R8 was way before my time! Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted July 17, 2008 Share Posted July 17, 2008 65 is the magic number on front hub assemblies It's the wheel bearing lock nut torque too Mo Quote Link to comment Share on other sites More sharing options...
pat_pending Posted July 17, 2008 Share Posted July 17, 2008 I think the problem arises because the bolts not only have to hold the flange to the hub in tension, they also have to transmit the drive, in shear. There is clearance around the bolts in the flange allowing a small amount of twist. The flange is always going to work loose no matter how tight you get the bolts. You need to prevent the twist by securely locating the flange to the hub. The answer i would imagine, would be to counter bore the hub and flange and fit hardened hollow dowels to take the shear force. Not sure there is enough material around the bolt holes though. Another possibility would be to get special bolts with a precision ground shank that would be a tight fit through the flange and into a counter bore in the hub. Quote Link to comment Share on other sites More sharing options...
Henry Webster Posted July 17, 2008 Share Posted July 17, 2008 I use standard lock washers on the rears and none on the front. Bolts are replaced often, but are just Allmakes OEM spec supplied with thread lock. Not had much of a problem since we renewed the hubs. We're really careful not to over tighten. Some of the rears do back themselves off slightly - but we just keep an eye on them in service. H Quote Link to comment Share on other sites More sharing options...
Daan Posted July 17, 2008 Share Posted July 17, 2008 12.9s, schnorrs and do them up FT have solved all my problems. Daan Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted July 18, 2008 Share Posted July 18, 2008 Yep as Steve90, Dann and ciderman says. I used to get this. Remove the bolts (should be easy ) buy some 12.9 alen heads, clean with brake cleaner, blow out the thread holes with same brake cleaner etc new gasket LOTS of locktite 242 will do or 243 or prob any of the liquid type threadlocks from loctiti and as others have said do up FT vs normal torque, let it all go off overnight too, don't whizz of straight away (ask me how I know that one ) I also use what looks like a socket with a bit of allen bolt sticking out this way Mr Rachet can be used to dogthem up Nige Quote Link to comment Share on other sites More sharing options...
bill van snorkle Posted July 18, 2008 Share Posted July 18, 2008 Have a look at the rear hubs of most trucks . They don't retain the halfshafts with bolts.It is difficult to tighten a bolt sufficiently if it isscrewing into softish metal, but if you loctite a stud in place you can generally apply more clamping force with a nut withoutfear of stripping the thread in the hub.Replace the bolts with studs and quality nuts,I did that on a series 3 once and it solved the problem permanently. I've also noticed recently that some engines modified for racing such as Australian V8 supercars have their cylinder head bolts replaced with studs and nuts,although the reason maybe that studs allow components to be regularly dismantled without wearing the threads away on the cast iron or alloy blocks..Rolls Royce V8's have studs as standard. Are those suffering from bolts working loose running separate drive flanges or one piece halfshafts? If the bolts are stretching, what is causing it ? Is a slightly bent axle housing or stub axle, or loose wheelbearings causing the halfshaft to transmit drive whilst being bent into a curve instead of being straight? That will cause the bolts to stretch or break, or frett away the splines on the drive flange and or halfshafts. Bill. Quote Link to comment Share on other sites More sharing options...
nas90 Posted July 19, 2008 Share Posted July 19, 2008 Have a look at the rear hubs of most trucks . They don't retain the halfshafts with bolts.It is difficult to tighten a bolt sufficiently if it isscrewing into softish metal, but if you loctite a stud in place you can generally apply more clamping force with a nut withoutfear of stripping the thread in the hub.Replace the bolts with studs and quality nuts,I did that on a series 3 once and it solved the problem permanently. I've also noticed recently that some engines modified for racing such as Australian V8 supercars have their cylinder head bolts replaced with studs and nuts,although the reason maybe that studs allow components to be regularly dismantled without wearing the threads away on the cast iron or alloy blocks..Rolls Royce V8's have studs as standard. Are those suffering from bolts working loose running separate drive flanges or one piece halfshafts? If the bolts are stretching, what is causing it ? Is a slightly bent axle housing or stub axle, or loose wheelbearings causing the halfshaft to transmit drive whilst being bent into a curve instead of being straight? That will cause the bolts to stretch or break, or frett away the splines on the drive flange and or halfshafts. Bill. My rear half shafts are from KAM with a separate drive flange, fronts are upgraded 110 CV's from KAM with short drive member and separate drive flange. Instead of the LR paper gasket I use a good quality auto black silicone sealant gunned onto the drive flange which also tends to coat the screws when compressed. Clean screws and hub thread with brake cleaner or acetone and blow-out with air gun. I use a dab of copper ease on the bolt thread and do up tight but not FT. I always check the screws especially left rear before setting-off for a days off-roading just part of the oiling and greasing and wheel nut checks I normally do the night before. Not had too many problems recently but those bolts do need checking and if you use loctite and they come loose you really need to remove and clean because the old loctite will jam the threads and come loose very easily. I like the idea of studs and nuts might try and source the parts for a test, would be good to do one side only and check for tightness on a regular basis and compare. Quote Link to comment Share on other sites More sharing options...
dirtydiesel Posted July 20, 2008 Share Posted July 20, 2008 A solution i've used is drilling and tapping the hub to m12 and then reaming the holes out in the drive flange to 12mm dead then useing quality bolts with a short shank. cone washers are very very good at stopping these bolts coming undone as they put the bolt under constant sprung tension- even when undone the cone washers tend to hold the drive flange in place- last tme i needed liberal applications of tool number one to get the drive flange off. They are so effective that you actually only torque the bolts to a few Lb/Ft- 18 iirc. Not sure if they are used in the landrover world anywhere, but they are used ont he drive flanges of Landcruiser axles. Most about all jap stuff has them not just 'cruisers, and as you say they work really well. Quote Link to comment Share on other sites More sharing options...
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