vibration-shimmy underload

[AndyCook]

todays checking

Today

I have jacked up front of the LC,
chocked back wheels

and run car in gear so that front wheels spin.
I also tried with front wheels off.

The vibration is evident when doing this. cant be wheel balance as wheels were off.

one thing i can see if wobble in both front axle drive-shafts, I guess this is related to the CV cups on both inner sides having up-down movement.
doesnt seem to be inside the CV joint - CV's dont click on lock either
no diff oil leak
i have changed the diff oil anyway, not metal came out

so it seems the vibrations are something to do with front diff or CV joints -

and another problem now - sodding ABS light has come on after doing this..... need to figure out how to reset that?

 

[AndyCook]

how do you edit posts?

read ABS codes - due to decelerator sensor - guess becuase car wasnt moving, but wheels spinning and braking!
reset the codes,
ABS warning light now off, and ABS works when i braked on some gravel - phew!

 

[AndyCook]

Re: vibration-shimmy underload - THINK THIS NOW FIXED!!!

ordered some old man emu 0881 (+50Kg) springs from devon 4x4 recently
fitted them now, using a workshop spring compressor i bought - the clarke workshop one - saved a lot of hassle, still a bit of faff to use, but far easier than the hand ones- its the one Chris has posted a link for before. well worth the £100 and i used it on other car recently too

well the front now sitting at 34cm both sides (between top of rim and arch)

before i fitted any new springs the front was
offside front: 30.5cm
nearside front: 32.5cm

after fitted the previous springs = OME882 (3-0822) 51-110kgs 40mm Lift
i had 39 cm at front both sides

Then installed winch and winch mount = dropped to 37cm
now down another 3cm each side to 34, but still a lift on original springs

BUT main thing is the vibration problem seems to have disappeared or not very noticable, only done a short test drive and didnt notice/feel it this time!!
front doesnt look higher than back anymore either.

shame to loose the extra lift the 882 springs gave, but they were too stiff and high, and somehow caused the bad vibes, that even a front diff drop kit didnt prevent.