Hybrid_From_Hell Posted December 16, 2017 Share Posted December 16, 2017 Oooooooh Tommorow (was planning to today but things got complicated) am changing my Half Shafts. The ones I have at present (Presold so don't ask ) are KAM 'Aerospace' Grade, which are pretty much the same strength as Ashcrofts HD (made in same factory - just different in minor places) , which are significantly stronger than standard, and look 1,000,000 better. I am upgrading to 300M, which are artwork and just plain beautiful....as you will see in the pics. But, I am doing this mini Tech article, as there is a load of nonsense talked about half shafts etc, so here we go with some pics and numbers, and advise but in simple terms. Standard Half Shaft - Genuine LR circa £600 Pair / Britpart HD £60 These will break like they have been sawn in half, the break is clean and small bits of swarf, they can break either end but rarely in the middle. the 2 reasons for breaking when overloading is the quality of the metal and lack of after finishing, plus poor radius on the sheer points, so you can upgrade. We had the Aerospace grade KAM units tested when I worked there, and we sent a Britpart HD unit too, that failed below standard LR unit. Break around 3300 ish Nm Twist KAM / Ashcrofts - Circa £300 Pair KAM do / did 3 Grades. The HD (old and not much stronger than standard in 32 spline EN19 ) but the HD stronger than standard shear about 4200 Nms, and then the best - which they called Aerospace (for some odd reason). These Like Ashcroft HD shafts are made from 4320 alloy steel, with transitional Heat treatments and other better things, like the radius are better,, which are often weak stress points where they will shear and overall costs far more to make and hence the jump in price. However, when these break (which they can - nothing is unbreakable) they tend to shatter like stick of Brighton rock hit by a hammer, with big shards going everywhere, and they can destroy your diff in a nano second, but far far stronger. Pointless fitting on a standard diff, the weak point will be your 2 pin diff, and it that breaks in can damage the shafts, so, IMVHO fit HD shafts when you fit a Locker, ATB, LSD, 4 pin etc, as now the weak spot is your shafts not the diff....It you Do NOT upgrade to KAM / Ashcroft shafts when you upgrade your diff, your shafts could easily destroy you new diff... Shearing here is around 7500 Nms ish Thats a HUGE increase in strength Ashcrofts 300M - Circa £580 Pair Artwork (see the pics !) These are actually made differently to any of the above, the metal is massively stronger, and hugely more expensive, but the shafts are wasted slightly in the centres to allow for greater flexing before breakages. When these break it will prob destroy anything in its path, I have seen only one and it broke a rear hole right through the axle tube, and destroyed a Quaiffe ATB at the same time. However, in its defense the driver said he was not surprised as it was "A severe mad red mist moment of insanity and expected to either die or be seriously injured lol" The break point for these due to better metal, treatments and waisting is estminated in excess of 9700Nms Ish With either the KAM or Ashcroft HD or 300m you really need to fit the Ashcroft / KAM drive flanges. The pattern stuff is poor quality and the splines will not thank you for it. Lastly with all of the above run EP90, not 80/90 or 85/90, EP90 is very different and helps protect best. Buy a drum from a Tractor / agricultural shop vs Halfords and you'll be surprised how cheap a small 25 litre drum can be ! As an aside I have removed the oil seals and run EP90 in all hubs front and rear, not grease, to do this cut off the rubber on the dowty seals and run RTC3511 oil seals which the early RR had pre going over to grease, and are a direct swap fit in the rear of the Hubs front or rear. Pics to follow tommorow If I can bring myself to fit them once unpacked ! Nige 1 Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted December 16, 2017 Author Share Posted December 16, 2017 "FFS nigel...can you leave those bloody 300m shafts alone . ..and pay sone attention other than them please. Christ amazed you don't take the bloody things to bed" eh ? what's that love... .just coming dear"... 1 Quote Link to comment Share on other sites More sharing options...
Soren Frimodt Posted December 16, 2017 Share Posted December 16, 2017 Great stuff Nige! Quote Link to comment Share on other sites More sharing options...
toenden Posted December 17, 2017 Share Posted December 17, 2017 Nice write up! Have you got any experience with the breakingpoint for the original v8 rears? They do seem a bit beefier to my untrained eye 😀 /mads Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted December 17, 2017 Author Share Posted December 17, 2017 V8 rear are difference as drum braked. They weere slightly flared, but not much stronger than standard, the poor V8 they put in it was strngled from birth BHP wise LOL And now, all I have to do is finish drilling out the sheared off bolts in the hub and refit .. 30 mins job my "Person Resembling a Pink Starfish" Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted December 17, 2017 Author Share Posted December 17, 2017 ^^ Must check out swear filter later - WTF is that ^^^ 1 Quote Link to comment Share on other sites More sharing options...
Daan Posted December 17, 2017 Share Posted December 17, 2017 So Nigel, what do you think is currently the weak link with these shafts installed? Daan Quote Link to comment Share on other sites More sharing options...
V8 Freak Posted December 17, 2017 Share Posted December 17, 2017 Probably the wheel studs Daan...... Quote Link to comment Share on other sites More sharing options...
Snagger Posted December 18, 2017 Share Posted December 18, 2017 It's crazy, the price for LR genuine shafts compared to the 300M! Quote Link to comment Share on other sites More sharing options...
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