Badger90 Posted December 3, 2008 Share Posted December 3, 2008 hi there.. i'v just finshed fitting a disovery transfer box in my defender, what a different it has hade.. much more nippyer. anyway as there is a differnt ratio and the speedo is calibrated to 1.410 ratio and i ahgve put 1.222 ratio.. i need to get the speedo re-calibrated? cheers Quote Link to comment Share on other sites More sharing options...
JST Posted December 3, 2008 Share Posted December 3, 2008 no need it takes the feed off the output shaft, your shaft is spinning quicker per RPM per gear so speedo reads higher. edited to add: is it not slower accelerating but faster top end, or do you hold the gears longer so accelerating is (or seems to be) quicker? Quote Link to comment Share on other sites More sharing options...
bango690 Posted December 3, 2008 Share Posted December 3, 2008 have just put a disco transfer box out of a 300 auto into a c rag 90 and the speedo does not fit, do i thatke off the brake drum. and the out put shaf and swap over for the 1 on the lt77 set up? Quote Link to comment Share on other sites More sharing options...
Badger90 Posted December 3, 2008 Author Share Posted December 3, 2008 no need it takes the feed off the output shaft, your shaft is spinning quicker per RPM per gear so speedo reads higher.edited to add: is it not slower accelerating but faster top end, or do you hold the gears longer so accelerating is (or seems to be) quicker? oh right. so i dont really need to touch the speedo then? cheers well i have a uprated intercooler and tweaked fuel pump but all the gear pull fine apart from 5th seems to take a little longer, not sure the affects on standerd engine, it is if not quicker then the 1.410 box becuase it holds in gear longer and your not spending half your time changing gear. yeah its a better top end, so it not reving the nuts off it at 70 and now it cruses which i great (hills and head winds should be interssting).. Quote Link to comment Share on other sites More sharing options...
JST Posted December 3, 2008 Share Posted December 3, 2008 have just put a disco transfer box out of a 300 auto into a c rag 90 and the speedo does not fit, do i thatke off the brake drum. and the out put shaf and swap over for the 1 on the lt77 set up? arent they both LT230s, i believe they are so speedo should fit unless the disco had a different female connector on the gear and you need to change it for a defender gear. Quote Link to comment Share on other sites More sharing options...
Badger90 Posted December 3, 2008 Author Share Posted December 3, 2008 have just put a disco transfer box out of a 300 auto into a c rag 90 and the speedo does not fit, do i thatke off the brake drum. and the out put shaf and swap over for the 1 on the lt77 set up? is it a v8 engine? v8's have a santana gear box which is differnt to lt77 and r380 as far as i know, if you take the hand break drum off, and thewre is 4x 15mm bolts.. undo them and take the pin out if the hand break mechinisam, where the speedo plugs in, that unit will come out with a little screwdriver leavering.. its saves changing the hole rear out put shaft unit.. here are some picture (go down the bottom few pictures to see about speedo drive) http://forums.lr4x4.com/index.php?showtopic=14601 Quote Link to comment Share on other sites More sharing options...
western Posted December 3, 2008 Share Posted December 3, 2008 speedo calibration is done by the speedo cable drive gear in the transfer box, just swap the Discovery one for your vehicles original, which will be more suitable for the tyre sizes of 7.50x16,235/85x16 & 255/85x16. Quote Link to comment Share on other sites More sharing options...
Badger90 Posted December 3, 2008 Author Share Posted December 3, 2008 speedo calibration is done by the speedo cable drive gear in the transfer box, just swap the Discovery one for your vehicles original, which will be more suitable for the tyre sizes of 7.50x16,235/85x16 & 255/85x16. oh great thanks, cheers Quote Link to comment Share on other sites More sharing options...
q-rover Posted December 3, 2008 Share Posted December 3, 2008 speedo calibration is done by the speedo cable drive gear in the transfer box, just swap the Discovery one for your vehicles original, which will be more suitable for the tyre sizes of 7.50x16,235/85x16 & 255/85x16. Should take all of 7 mins with a coffee break. Follow wire to transferbox, undo bolt, remove gear, replace with new. Have coffee Refitting is the reversal of removal. Stand back and feel chuffed. Quote Link to comment Share on other sites More sharing options...
western Posted December 3, 2008 Share Posted December 3, 2008 oh great thanks, cheers if it's on 7.50 or bigger tyres, the drive gear needs to be blue & 20 teeth. more info here Quote Link to comment Share on other sites More sharing options...
cabell Posted December 4, 2008 Share Posted December 4, 2008 Does anyone know which tranducer will give the most accurate reading for 33" tires (255/85) with the 1.2 tcase on an electronic td5 speedo? My gearbox is an lt77. Quote Link to comment Share on other sites More sharing options...
JST Posted December 4, 2008 Share Posted December 4, 2008 if it's on 7.50 or bigger tyres, the drive gear needs to be blue & 20 teeth.more info here Does anyone know which tranducer will give the most accurate reading for 33" tires (255/85) with the 1.2 tcase on an electronic td5 speedo? My gearbox is an lt77. the blue 20tooth one its designed for the 7.50/235/53 tyres but over reads and when fitted with 255/85s you get a bang on reading (well mine is with that setup (1.4 case which makes no odds) against GPS) Quote Link to comment Share on other sites More sharing options...
q-rover Posted December 4, 2008 Share Posted December 4, 2008 the blue 20tooth oneits designed for the 7.50/235/53 tyres but over reads and when fitted with 255/85s Speedo's are supposed to overread. What's the problem? Better to think your driving at 70, but actually 66, rather than 76. Quote Link to comment Share on other sites More sharing options...
western Posted December 4, 2008 Share Posted December 4, 2008 Does anyone know which tranducer will give the most accurate reading for 33" tires (255/85) with the 1.2 tcase on an electronic td5 speedo? My gearbox is an lt77. the blue 20 tooth gear does all the sizes I've detailed above. my own 110 runs a R380/LT230 1.41 transfer box on 255/85 tyres & my Td5 type speedo is bang on. Quote Link to comment Share on other sites More sharing options...
Badger90 Posted December 4, 2008 Author Share Posted December 4, 2008 i comperd it with the sat nav.. and it reading about 2-3mph under.. Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted December 4, 2008 Share Posted December 4, 2008 Bear in mind that it also affects the odometer. So if you put 100,000 miles on it with a spedo over-reading by 5% then you'll only have actually put 95,000 miles on it Quote Link to comment Share on other sites More sharing options...
Badger90 Posted December 4, 2008 Author Share Posted December 4, 2008 Bear in mind that it also affects the odometer. So if you put 100,000 miles on it with a spedo over-reading by 5% then you'll only have actually put 95,000 miles on it good point.. Quote Link to comment Share on other sites More sharing options...
JST Posted December 5, 2008 Share Posted December 5, 2008 Speedo's are supposed to overread. What's the problem?Better to think your driving at 70, but actually 66, rather than 76. never said there was a problem, i was explaining what would work with his set up of 33" tyres with which pinion and why it would work in my experience. Quote Link to comment Share on other sites More sharing options...
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