Steve 90 Posted July 31, 2009 Share Posted July 31, 2009 Mmm, 4 stub axles but only 2 modified hubs???? I would assume by that the rear hubs are still usable despite the larger stub axle just with some different bearings fitted. Whats the difference that makes this possible with the rear hubs but not with the front? Quote Link to comment Share on other sites More sharing options...
Daan Posted July 31, 2009 Share Posted July 31, 2009 Is there any choice in ratios? 4.1 is pretty high for anything bigger than 35". Daan Quote Link to comment Share on other sites More sharing options...
ashtrans Posted July 31, 2009 Author Share Posted July 31, 2009 Mmm, 4 stub axles but only 2 modified hubs???? I would assume by that the rear hubs are still usable despite the larger stub axle just with some different bearings fitted. Whats the difference that makes this possible with the rear hubs but not with the front? good point Steve, I should have said 4 modified hubs ! Quote Link to comment Share on other sites More sharing options...
ashtrans Posted July 31, 2009 Author Share Posted July 31, 2009 Is there any choice in ratios? 4.1 is pretty high for anything bigger than 35".Daan initially no, these are real special ring and pinions costing us nearly £ 500 each on a batch of 30 , I shan't be making a big range of ratios hoping they may sell, more may be introduced later if they sell OK, Quote Link to comment Share on other sites More sharing options...
jcwcooper Posted August 1, 2009 Share Posted August 1, 2009 initially no, these are real special ring and pinions costing us nearly £ 500 each on a batch of 30 , I shan't be making a big range of ratios hoping they may sell, more may be introduced later if they sell OK, Ouch £500 each! Although 7k for all that doesnt seem too bad considering that there will no need to make new axle casings fit the LR. They do look good! Dave. Quote Link to comment Share on other sites More sharing options...
Lara Posted August 1, 2009 Share Posted August 1, 2009 I take it that the Ford 9" R&P wont fit then? Lara Quote Link to comment Share on other sites More sharing options...
ashtrans Posted August 2, 2009 Author Share Posted August 2, 2009 I take it that the Ford 9" R&P wont fit then?Lara the £ 500 would be for our version of the hi-pin 35 spline mega high 9, we are considering making another casing to accept the normal low pin Ford 9" which would be much cheaper but wouldn't have the benefits of being high pin, there are many variations possible which can be developed over time but at the moment we just want to get these 2 axles on a truck and get them tested. Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted August 2, 2009 Share Posted August 2, 2009 the £ 500 .............................. Good Grief that much for a few gears lashed up and jammed into some casing and then pretending to be the 'New Axles Diffs' for a LR 4x4 Do I get a Moderators discount for this complete and utter lash up ? Seriously..... what a joy to see thinking 'outside the box', and of a quality and from a company so many agree is both Value for money anyway ........and quality (That should secure my 100% discount ) Just a joy to read and see, ......lovely workmanship as always Nige Quote Link to comment Share on other sites More sharing options...
moose Posted August 3, 2009 Share Posted August 3, 2009 we are considering making another casing to accept the normal low pin Ford 9" which would be much cheaper but wouldn't have the benefits of being high pin. I have prob missed this else where in the thread but what are the benefits of having a high pinion? I can see that it would help keep pinion a bit further away from the action.. Quote Link to comment Share on other sites More sharing options...
Bush65 Posted August 3, 2009 Share Posted August 3, 2009 I have prob missed this else where in the thread but what are the benefits of having a high pinion? I can see that it would help keep pinion a bit further away from the action.. For the front, it allows room under the pinion for the track rod. The higher pinion reduces the operating angles of the u-joints and gets the drive shaft up away from damage. For 9" are very strong ring and pinion in a small package, because they have a very large hypoid offset. In low pinion version the pinion is very low with adverse affects. Quote Link to comment Share on other sites More sharing options...
ashtrans Posted August 5, 2009 Author Share Posted August 5, 2009 thanks Bill, I would agree, main advantages are better clearance and prop angles, Quote Link to comment Share on other sites More sharing options...
plasticbadger Posted August 5, 2009 Share Posted August 5, 2009 Am I also correct in understanding that the high pinion layout increases contact area between ring gear and pinion, thus increasing strength? Moose, have a gander at my front TLC diff, which is high pinion, and you'll see the effect on prop angle and steering clearance. Quote Link to comment Share on other sites More sharing options...
ashtrans Posted August 5, 2009 Author Share Posted August 5, 2009 Am I also correct in understanding that the high pinion layout increases contact area between ring gear and pinion, thus increasing strength? not really, this is governed by the amount of hypoid offset, ie distance from the ring gear centreline to the pinion centreline, on the ford 9" this is 2.25" which is a lot in hypoid terms, the high and low pinion just refers to the pinion being above or below the ring gear centreline but both have the same 2.25" offset. Quote Link to comment Share on other sites More sharing options...
webbsite Posted November 7, 2009 Share Posted November 7, 2009 Hi Dave, Is there any update on the successes of the axles? Regards, Roger Quote Link to comment Share on other sites More sharing options...
zoltan Posted November 7, 2009 Share Posted November 7, 2009 Dave/Ian, If you feel LM25TF is marginal but you want to run with an alloy casing yuou might like to consider a similar alloy, L169 which could be hipped after casting to further improve its properties. L169 is chemically similar to LM25 but has both high tensile strength and usefully better elongation. You can compare the specs here http://www.creasey-castings.co.uk/dataSheetBsLM25.html http://www.creasey-castings.co.uk/dataSheetLM169.html Quote Link to comment Share on other sites More sharing options...
ashtrans Posted November 8, 2009 Author Share Posted November 8, 2009 Hi all, some updates : the axles are being tested by Jim Marsden of Gigglepin 4x4 on his challenge 90, they have done 3 competitions so far. As this is testing our instructions to Jim were to batter them and not hold back. 1) about 8 weeks ago Jim did the Portugese Rainforest challenge and came 2nd, the rear diff housing developed a crack and oil leak due to a whack on a rock, also ARB's had bad air leaks as the air was fed through the casing which turned out to be porous. Diffs were stripped, crack welded up, air leaks fixed, axles refitted. 2) 5 weeks ago was the 'de-cider' challenge event in cornwall, after 2 hours on the first day the rear diff housing developed a large crack top to bottom in a totally different place the the first crack. This was caused by the huge side forces generated due to the pressure angles when the rear is driving on the coast side of the ring gear. The journal end caps are being forced apart and the crack started from a weak point we had made by drilling the ARB air feed near a mounting hole. One ARB still leaked. This was bad news and needed radical measures, many changes were made : the pattern was altered to beef up the strengthening ribs from 15 to 40mm the material was changed to 500/7 cast iron, approx double the strength, we looked at different ways to limit the deflection of the journal end caps, ie a tie bar between the 4 journal end cap bolts but this could not be done due to the crown wheel being in the way. We decided on a different method, the fixed HD diff pans were removed and a 12mm thick steel ring welded on with a 15mm wall thickness, this was drilled and tapped to accept a bold on diff cover but was also drilled and tapped with 2 holes on each side so M10 bolts could be fitted and screwed in until they lightly touched on each side of the end caps then lock nutted, the idea being that this will help to reduce the end caps spreading. The bolt on diff pan can also be removed for inspection and can be rotated to allow different oil levels. ARB air lines were also fitted differently and fed through this ring to minimise weak points in the main housing. 3) Last weekend Jim did the Pheonix challenge event in scotland, no failures and no air leaks. We want to see him do at least 2 more hard events with no problems before we look at going into production. Quote Link to comment Share on other sites More sharing options...
white90 Posted November 8, 2009 Share Posted November 8, 2009 Superb detailed report this is why people trust decent suppliers. Quote Link to comment Share on other sites More sharing options...
landroversforever Posted November 8, 2009 Share Posted November 8, 2009 Fascinating stuff I think this perfectly demonstrates what a great company Ashcrofts are! Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted November 8, 2009 Share Posted November 8, 2009 Dave I might have missed something, or simply become dyslexic, but is this diff specifically designed for front application only ? If used in the rear will the ring and pinion be driving on the coast side of the teeth? If so does the higher thrust loads due to higher pressure angle of the teeth on the coast side give you any cause for concern? Bill. Dave, I hope you don't think I'm being picky or critical just for the sake of it. Like yourself, differentials and transmissions have been a bit of a pet subject for me for many years, both professionally and as an enthusiast. I've seen and repaired them all from Citroen 2cV's to 150 ton heavy haulers and know that there is nothing that can't be broken. I'd like your product to be successful right off the bat and if you have already previously considered the points I have raised please feel free to ignore them. If you haven't I'll send you my bank account details by PM I've just remembered a time when a mate of mine with 9'' Ford diffs with LandRover ends front and rear in a LWB, powered by a chrysler 265 hemi of approx 200bhp on 31'' 7.50x16 tyres was attempting to climb an 18'' high earth bank on the side of my driveway, when the rear wheels spun. He backed off the throttle a couple of times and gave it another couple of squirts in an effort to get the tyres to bite. There was an almighty bang before the back of the propshaft fell to the ground together with the pinion and pinion bearing carrier assembly.The inside of the banjo housing was full of broken crownwheel teeth that had the appearance of being heavily loaded on the coast side.Surprisingly the Detroit No Spin carrier only had .001'' run out after all this trauma. Now admittedly the diff housing was a standard Ford grey iron one, unlike the considerably stronger nodular or even alloy ones ,but it just occurred to me that pegging the diff to reduce crownwheel carrier flex, particularly when shock loaded on the coast side would probably just cause this type of failure unless a substantial amount of extra material was built into the diff housing in the area around the pinion carrier bolt holes. Bill. Edit. Instead of having special alternative ratio Hi pinion crownwheels and pinions made, if that is what people want. how about mounting regular low pinion ones upside down and incorporate a 2 gear drop box on the pinion housing with alternative gearsets, similar to the so called quick change rear ends used in some racing applications? That way you could also ''clock'' the drop box to get the optimum propshaft angle for the rear and sump clearance up front Now if we can only get Bill and his crystal ball to calculate next week's lottery numbers we'll be sorted Quote Link to comment Share on other sites More sharing options...
Daan Posted November 10, 2009 Share Posted November 10, 2009 the pattern was altered to beef up the strengthening ribs from 15 to 40mm the material was changed to 500/7 cast iron, approx double the strength, Are you sure you cant make the setup work with an aluminium casting? I though a big advantage of your setup is that you also shed quite a bit of weight, which would no longer be the case. Spidertrax manage ok with an aluminium housing. Daan Quote Link to comment Share on other sites More sharing options...
ashtrans Posted November 10, 2009 Author Share Posted November 10, 2009 Hi Daan, whilst the ford 9" housing can be bought in aluminium this is not generally used for rock crawlers, more the 'weight sensitive' cars : strange eng the rock crawlers use 'Nodular Iron' : high 9 maybe the additional ribs and the ring to limit the end cap deflection would have been sufficient but at this stage we first need to produce a diff that is totally reliable. I will post up some pics in the morning. Quote Link to comment Share on other sites More sharing options...
zoltan Posted November 10, 2009 Share Posted November 10, 2009 Hi Daan, whilst the ford 9" housing can be bought in aluminium this is not generally used for rock crawlers, more the 'weight sensitive' cars : strange eng the rock crawlers use 'Nodural Iron' : high 9 maybe the additional ribs and the ring to limit the end cap deflection would have been sufficient but at this stage we first need to produce a diff that is totally reliable. I will post up some pics in the morning. The HIP'ing process is quite effective in improving integrity in aluminium castings. You said you had some evidence of porosity in the casing, maybe the foundry need to sharpen their act a little. HIP'ing would take away this as a potential failure point http://en.wikipedia.org/wiki/Hot_isostatic_pressing I see your logic of getting the whole deal working in iron first and developing it from there though. FWIW, I've used Creasey's for about 12 years for aluminium and magnesium castings: cylinder heads and suspension parts especially and they have always been first rate on price, delivery and quality Quote Link to comment Share on other sites More sharing options...
JST Posted November 10, 2009 Share Posted November 10, 2009 this is why people trust decent suppliers. totally agree, never had anything but excellent service from Ashcrofts, why cant all suppliers and manufacturers be like them. Quote Link to comment Share on other sites More sharing options...
bill van snorkle Posted November 10, 2009 Share Posted November 10, 2009 Dave,Are you using standard 9'' pinion bearings and bearing spacing ? My feeling is that whilst the carrier bearing end caps can certainly be reinforced and a thrust pad added to minimise crownwheel deflection, the loads on the too closely spaced and relatively light duty pinion bearings andpinion housing casting are excessive when driving on the coast side, leading to premature wear or failure of the needle roller straddle bearing or its mounting.Personal experience has indicated that even Salisburies with their much larger and more widely spaced pinion bearings and lower pressure angles get a bit sloppy when used hard in front axle applications. Bill. Quote Link to comment Share on other sites More sharing options...
will_warne Posted November 11, 2009 Share Posted November 11, 2009 Dave / Ian, there are a few people using Ali 3rds off road - mostly those either choosing to run low pinion of running in reverse (either because running rear engined or running portals). I'm going to be running low pinion diffs (in Strange Ali casings) for the strength and for the additional clearance so I'll have less issues with suspension and meaning I can keep the engine fairly low. Yes, I loose a bit of propshaft clearance but it isn't that much of an issue and I think it is worth the benefits. I would guess the reason most of the rock crawlers use a nod iron case is because hi 9's are expensive enough as it is and it isn't worth the extra cost of the ali housings (which they will do for special order) to save a few kgs. Plus, if you break a casing then the iron housings come off the shelf.... Personally, I'd look again at whoever did the original casting as that could be part of the issue. Quote Link to comment Share on other sites More sharing options...
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