Popular Post ashtrans Posted December 9, 2020 Popular Post Share Posted December 9, 2020 Hi Guys, a small tech thread to show you what we have been upto for those with the 6BT Cummins engines, this is meant as a non commercial technical thread to show how flexible the LT230 can be. features are : 0.900 Ratio, we have been aware for some time of demand for higher gearing for these low revving engines so after successfully making the 26 Tooth input gear for Reece to run with the 1.003 ratio gear set, we looked at how we could do this. Land Rover raised the ratios in the LT230 by reducing the diameter of the output gear but it was not possible to do this further as the 1.003 gear is already quite small and reducing it further would not be reliable so we made a new larger diameter input gear with 28T instead of 26T and this also allowed us to raise the output gear from 28 to 30T which helps strength. This gives an increase of 10.27% on high range. Increased width of gear teeth on the input gear and corresponding intermediate gear. Rather than leave wide air gaps between the 3 rows of teeth on the intermediate gear we have increased the width of the input gear and middle row of teeth on the intermediate gear by 4mm from 32.50mm to 36.50mm. Bigger bearing on high range side of intermediate gear. We have seen failures in the past of other brands of these input gears and I suspect these failures are related to the taper roller bearing in the intermediate gear failing on the high range gear side which then allows the intermediate gear to move out of mesh with the input gear teeth and the teeth then fail. We have machined the intermediate gear on the high range side to accept a 62mm diameter x 25mm wide bearing rather than the stock 52mm diameter x 22mm wide bearing. The bigger bearing has ratings of 64Kn Dynamic and 76Kn Static as opposed to the stock bearing having 54Kn Dynamic and 56Kn Static. This bearing (Timken brand) is supplied with a sleeve and spacer which are required to fit. See 'install' ref fitting notes. Please see below comparison of the standard bearing and the larger bearing supplied with the kit we are really quite chuffed with this, its taken about 9 months to get made and needs long term testing but the gears are from a proven supplier and gears are stronger than the 1.003 ratio which had no failures so I don't anticipate any issues, full blurb here : https://www.ashcroft-transmissions.co.uk/0-900-gear-set.html Cheers Dave 8 Quote Link to comment Share on other sites More sharing options...
landroversforever Posted December 9, 2020 Share Posted December 9, 2020 That's cool Dave . Nice to see aftermarket stuff still going on for the LT230. Quote Link to comment Share on other sites More sharing options...
Ed Poore Posted December 9, 2020 Share Posted December 9, 2020 It can be even more flexible if you wanted... I've got a mate who had a bunch of 0.7 ratio LT230 boxes made up a number of years ago not sure on the exact dimensions of the gears but they were shoved behind lots of different engines from ranging from 6.2 and 6.5 GMCs (with and without turbos) through to big blocks. There's still a few of them festering around in his yard. Quote Link to comment Share on other sites More sharing options...
Soren Frimodt Posted December 9, 2020 Share Posted December 9, 2020 Great stuff as always Dave 👍 Will also be nice for Those running portals 😉 Quote Link to comment Share on other sites More sharing options...
cackshifter Posted December 9, 2020 Share Posted December 9, 2020 Great to see the development still (and those Cummins motors can make some really big numbers) 👍 Quote Link to comment Share on other sites More sharing options...
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