Hybrid_From_Hell Posted October 25, 2009 Share Posted October 25, 2009 Hi All, Now have new Clutch, new Primary box (Ta Dave at Ashcrofts ) and rebuilt T Box, ...so nearly there When I picked up the front prop to fit the slider dropped out oh deep joy.. so I picked it up and popped it back together "In Phase" - (no, there were NO Marking at all - how helpfull) and fitted it. 1st Test run shows a rumble felt at all speeds up through the Gear Lever - me wondering..... Is a 90s front prop supposed to be in phase or out of phase ? If out of phase how do you set it without any Guide markings, I seem to have in my mind that out of phase is something like rear yoke being / must lead the front yoke by 2 splines ? HELP Please ! Nige Quote Link to comment Share on other sites More sharing options...
Les Henson Posted October 25, 2009 Share Posted October 25, 2009 V8_Freak put his front prop out of phase to cure a rumble. Les. Quote Link to comment Share on other sites More sharing options...
Guest noggy Posted October 25, 2009 Share Posted October 25, 2009 HFH there is loads on this forum about prop shaft phasing! But what i remember front prop should be in phase and rear prop out of phase. Quote Link to comment Share on other sites More sharing options...
western Posted October 25, 2009 Share Posted October 25, 2009 Nope front should be about 30 degee out of phase, rear prop in phase Defender workshop manual says --- the univesal joints on the front porp shaft are, by design NOT assembled in line with one another, nevertheless the alignment marks on the sliding member & prop shaft must coincide when assembling. Quote Link to comment Share on other sites More sharing options...
BogMonster Posted October 25, 2009 Share Posted October 25, 2009 Technically I should imagine to smooth out the lumps it should be about 45 degrees out of phase that way you get eight little lumps instead of four big ones. Quote Link to comment Share on other sites More sharing options...
jameslwt Posted October 25, 2009 Share Posted October 25, 2009 Fitted a new front prop yesterday on the 110 - imaqgine it's the same as a 90, and as Western says, the front was about 30 degrees out. (mine stayed in one piece) Quote Link to comment Share on other sites More sharing options...
Guest noggy Posted October 25, 2009 Share Posted October 25, 2009 Nope front should be about 30 degee out of phase, rear prop in phase Defender workshop manual says --- Well i knew it was one way or the other! ill blame the hangover Quote Link to comment Share on other sites More sharing options...
gruntus Posted October 25, 2009 Share Posted October 25, 2009 Bugger, when cleaning up my prop shafts on my project I actually pop marked the splines on the rear but forgot to do it on the front and only noticed when I went to reasemble. I used the rear for comparison and fitted it the same (in line). Not being lazy I just tried searching for previous threads but find the new search pretty cr*p compared to the last version (or is it just me?). It may be just operator error Can Ralph (or anyone else) confirm exactly how the UJ's should be offset/aligned and is the positioning/alignment/offset of the grease nipples important? Lucky for me I read this thread as I had never heard of this before Cheers G Quote Link to comment Share on other sites More sharing options...
western Posted October 25, 2009 Share Posted October 25, 2009 on the propshaft & the sliding part after careful cleaning you should find a lightly stamped or engraved in arrow like these ---> <--- on both parts of the shaft body, align these & that will set the phase of the propshaft. Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted October 25, 2009 Author Share Posted October 25, 2009 OK I can advise from today the results : The rear propshafts on 90s and RRs etc is absolutely 100% IN PHASE - ie yokes in line and the front prop, RR And 90s is 100% OUT OF PHASE So for mine I set "In Phase" then pulled apart and set the lead UJ / Yoke (TBox end 1 spline is advance and went for a drive - no difference removed and added 1 more = 2 spines in advance - drive = no difference 3 splines = Gone 4 spines = back and different So, front prop set at 3 splines in advance on lead Yoke. as to if this is 100% as it should be "Out" of phase I don't know but seems fine. Maybe a grown up will be along with the conversion of 3 splines in terms of degrees which seems to be around 30 Degrees ? Anyway, With new (sh good ) flywheel, New ashcroft LT85, reselaed re bearinged re shimmed T Box and new 3x Prop UJs and out of phase prop........ its like a new truck Nige Quote Link to comment Share on other sites More sharing options...
western Posted October 25, 2009 Share Posted October 25, 2009 glad you fixed it & without splashing out more cash too, got to be a bonus, I'd reckon about 30degrees too. Quote Link to comment Share on other sites More sharing options...
bluespanner Posted October 25, 2009 Share Posted October 25, 2009 Technically I should imagine to smooth out the lumps it should be about 45 degrees out of phase that way you get eight little lumps instead of four big ones. That makes it worse! Quote Link to comment Share on other sites More sharing options...
ashtrans Posted October 26, 2009 Share Posted October 26, 2009 Hi Technically it should be 45deg out of phase, when a single U.J. is working (at an angle) it produces a 'torsional oscillation' at 4 times rotation speed. If the drive flanges are parallel then '0' phase difference as the oscillation at one end cancels the other. If you now introduce a different angle between the two ends the 'torsional oscillation' will not cancel out. You can 'phase' one joint in relation to the other but this only masks the inherent problem. As the prop angle at the diff end (front only) is approx zero (unless a lift kit has been added) the other (gearbox) end is constantly fighting it. Fitting a 'double cardan' at the gearbox end reduces the oscillation to that produced at the diff which is usually minimal. I thought LR front props had a 'King' spline to ensure correct alignment??. If your still reading this Nige has the practical approach which does work, kind of, double cardans are a pain particularly on a comp motor. Regards Ian Ashcroft Quote Link to comment Share on other sites More sharing options...
V8 Freak Posted October 26, 2009 Share Posted October 26, 2009 I did mine one or two splines only and it's quietened down totally... It's definitely not 45 degrees out of phase and I've never found any arrows on the prop when cleaned up and on the bench. As I've manageed to re-aling several times I can only assume there is no king spline as you suggested Ian... I'll have a look at the spare in the garage tonight! Neil Quote Link to comment Share on other sites More sharing options...
bow Posted October 26, 2009 Share Posted October 26, 2009 On my front prop i have an arrow on the prop tube as described above and a dot punch on the uj, both my props are genuine lr replacements, may be of some help, atb BOW.. Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted October 26, 2009 Share Posted October 26, 2009 I most certainly haven't got a king spline on my discovery propshaft. I took it apart and re-phased it for a series motor for the reasons Dave outlined above - the series diff and gearbox flanges are parallel. Quote Link to comment Share on other sites More sharing options...
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