R

razz007

New Member
hello everyone , well i`ve had my disco 2 for a half a day and i have flushed out the fuel filter to get rid of the dashlight . i`ve ordered some discs and pads from paddock , mine passed an mot wednesday but they look worn to me and i`m fussy :) coming with the discs is a mudflap metal bit ? it goes in the arch above the rubber mudflap ( will learn correct names ) i`ve got a squeaky clutch pedal , soooo trying work out how to grease it , i so wanna try but how do ya bend to see up the inside where the pedals are ? ( me has had too many bike accidents , so i struggle like that ) if it beats me , i`ll try jsf norwich ? what a brill machine :) sorry to run on , but ya know how it is when you get a new toy :)
 
Looks nice.... though your first investment should be on 4 similar tyres which ever they are cos you'll kill the transfer box this way(unless i didnt see right that the front and rear tyres are different), it's not enough to be the same size believe me, they must be the same brand/modell too
 
hello there , the fronts are Michelin and the rears are kumho , the rears should be replaced next weekend :) but i can`t do that bit :(
 
sierrafery said:
Looks nice.... though your first investment should be on 4 similar tyres which ever they are cos you'll kill the transfer box this way(unless i didnt see right that the front and rear tyres are different), it's not enough to be the same size believe me, they must be the same brand/modell too
Click to expand...


Utter Bull****e... It int a fecking Gaylander you know.. :crazy:
 
Pikey said:
Utter Bull****e... It int a fecking Gaylander you know.. :crazy:
Click to expand...

:mad: RTFM...which means the D2 Owner's handbook page 158(RAVE), especially the WARNING...then the description/operation mode of LT230SE transfer box and the EBD and ETC operation of the ABS system... then you can be rude to me:rolleyes:
 
sierrafery said:
Looks nice.... though your first investment should be on 4 similar tyres which ever they are cos you'll kill the transfer box this way(unless i didnt see right that the front and rear tyres are different), it's not enough to be the same size believe me, they must be the same brand/modell too
Click to expand...
Sierrafery, I believe I remember this being discussed for the d2 as well a few years back on this same forum.
Coming from you, do you have any personal experiences with any of the possible problems that could be thrown up with the use of dissimilar tires on the d2?
Currently have a similar setup with different makes front and back and need to know if this won't cause any problems.
Cheers mate.
 
i dont have personal experience as based on all my research and study of the systems i didnt risk to put different tyres on my own car... but i know personally two guys who lost theyr transfer boxes and they both used different tyres ... knowing how the LT230 is built and how it works IMO it's more than a coincidental thing... but i may be wrong though cos mechanics is not my area of expertise so if the transfer box thing is suspect for you send a mail to Dave Aschroft and ask him cos i'm sure he will answer... but this is the smallest problem which can occur IMO

what i am certain about is that the ABS system will be completely mixed up and may become dangerous cos the SLABS will get uneven inputs from the axles while braking cos the action of the wheels is different due to theyr profile so the deceleration rate will be misscalculated and the stopping distance can increase considerably... so you can end up pushing the pedal which will become hard and pulsing while the car will not stop as expected(ABS +EBD)

it's a long and complicated theory but the gist of it is that the whole wabco system was calibrated from factory for the standard tyre dimensions and pressures, any difference will affect the system's behaviour... i dont want to make it too long but i can give any explanations and demonstrate with scientific arguments based on official descriptions and diagrams from wabco documents... beside that i made several bench tests and live tests with my own car and i can tell without any modesty that i know exactly how the D2 ABS system works... and my conclusion is that it's not 100% safe to use other than the recommended tyres at the recommended pressures... the fact that many owners have lifted cars with much bigger tyres and nothing bad happened untill now it's not a proof that it can't happen in the future, though i presume that those who made extreme mods have made them for off road usage and they'll not ride like the wind on motorways with them... at least i give a warning to be very carefull if it comes about braking from high speeds..... enough for now

i presume that Land Rover didnt give all those warnings in vain... see the owner's manual - tyres section cos there are only 3 pages nobody have to read RAVE and WABCO docs entirely like i did:) ... not once

you can believe me or not, i just want to help that's all
 
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dissimilar tyres and pressures wouldnt adversely effect t/box, it would shorten the center diff gear thrust washers and shafts but not so youd necessarily notice unless it was about buggered anyhow, it would be interesting to know what differential in wheel speeds is needed to have an adverse effect on abs system presumably there is some leeway as system has to work whilst cars not travelling in a straight line
 
jamesmartin said:
dissimilar tyres and pressures wouldnt adversely effect t/box, it would shorten the center diff gear thrust washers and shafts but not so youd necessarily notice unless it was about buggered anyhow, it would be interesting to know what differential in wheel speeds is needed to have an adverse effect on abs system presumably there is some leeway as system has to work whilst cars not travelling in a straight line
Click to expand...

good point ... that's why the TC used to kick in when you take of with the steering fully one side... cos it's below 10mph then and the system is still under self check

MY concern with different tyres is the brakeing action not the TC cos the TC is disabled for individual wheel controll above 31.3mph

the ABS action is exptremely complex and it has a special control algorithm named MIC = Modified individual control, for all the vehicles where WABCO system is used the threshold and refference values are calibrated for that specific vehicle based on the builder's data...these figures were not made public by WABCO in any document(and i've seen many)... they explain the operation mode with graphs and if you have engineering knowledge seeing those schemes you can presume that the limits are quite tight...from my tests and readings i can estimate that a signal difference up to 5-10% decreasing with speed is accepted by the system as to not throw sensor signal fault codes... otherwise while braking every input is taken into account by the system that's why you'll not find two D2s to stop EXACTLY on the same distance on the same surface unless ALL the elements are EXACTLY similar(weight, wheel size/profile/pressure/wear, pressure applied on the pedal/in the system...and so on and on)...in the figure attached(from official WABCO document) the difference between -b and +b in the middle scheme is 10%(for D2 based on some of my calculations cos for other cars it might be different), i can't attach the whole file here cos it's too large

ABS action graph.jpg
 
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cor , awesome reading , I`ve always gone the same tyre route , basically cos on a moped all the time , but the disco is booked in for new rear tyres this very Saturday :) new front discs n pads in the post too , next I`ll do some wax oiling , superb :D
 
sierrafery said:
i dont have personal experience as based on all my research and study of the systems i didnt risk to put different tyres on my own car... but i know personally two guys who lost theyr transfer boxes and they both used different tyres ... knowing how the LT230 is built and how it works IMO it's more than a coincidental thing... but i may be wrong though cos mechanics is not my area of expertise so if the transfer box thing is suspect for you send a mail to Dave Aschroft and ask him cos i'm sure he will answer... but this is the smallest problem which can occur IMO

what i am certain about is that the ABS system will be completely mixed up and may become dangerous cos the SLABS will get uneven inputs from the axles while braking cos the action of the wheels is different due to theyr profile so the deceleration rate will be misscalculated and the stopping distance can increase considerably... so you can end up pushing the pedal which will become hard and pulsing while the car will not stop as expected(ABS +EBD)

it's a long and complicated theory but the gist of it is that the whole wabco system was calibrated from factory for the standard tyre dimensions and pressures, any difference will affect the system's behaviour... i dont want to make it too long but i can give any explanations and demonstrate with scientific arguments based on official descriptions and diagrams from wabco documents... beside that i made several bench tests and live tests with my own car and i can tell without any modesty that i know exactly how the D2 ABS system works... and my conclusion is that it's not 100% safe to use other than the recommended tyres at the recommended pressures... the fact that many owners have lifted cars with much bigger tyres and nothing bad happened untill now it's not a proof that it can't happen in the future, though i presume that those who made extreme mods have made them for off road usage and they'll not ride like the wind on motorways with them... at least i give a warning to be very carefull if it comes about braking from high speeds..... enough for now

i presume that Land Rover didnt give all those warnings in vain... see the owner's manual - tyres section cos there are only 3 pages nobody have to read RAVE and WABCO docs entirely like i did:) ... not once

you can believe me or not, i just want to help that's all
Click to expand...
Very informative.... thanks mate.
 
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