Hi & thanks for all the help in the forum

[vib6er]

Hi all
would like to say thanks to all the forum contributers, used the forums to rectify a bad vib on my def 90 300tdi after fitting a 2inch lift.
In short I had a new rear wide angle prop prior to the lift, which was working fine, post lift had bad vibs through body and steering wheel. found the front prop had zip clearance so put a wide angle in, vibs better but still there.
Next stop corrected the rear diff nose up angle to nose level(in three stages), vibs better again but still annoying.
Next step- panic!- should I have bought double cardens! Lets try- after more test runs/props in&out- a phase shift on the front prop, Yes! vibs gone.
next stop rear prop back in -vibs back! Sh!te.
Next stop more searching, check front axle position, its 7mm out- only did a 2inch lift but the actual hieght gain was 4inch.
Adjustable panhard rod set up and steering damper cx and my ordeal is over, well I think it is, what front axle alignment has got to do with rear vibs I don`t know. Still got a little between 35-40 mph, but i`m happy with her again!
Had an oil cooler pipe split on me in between all that aswell, still learnt alot.:beer2:

 

[lorri789]

Top first post! :cool2:

 

[aaronmorris]

:welcome:

 

[vib6er]

Update:
been running without rear prop- all was good- took the plunge and went for a double carden on the rear, she vibrates again!. Took out the rear trailer arm spacers and its got a lot better, trans box to rear diff flanges not in parallel but i,m getting close to smooth 4 wheel drive. have read and been advised that they need to be parallel?
Does the cardan end need to be at the trans box?
Would a phase shift be worth ago?
Taking her out for anouther diag run with a fresh head tommorow,any tips would be apriciated.

 

[BenKenobi]

Prop UJ's aren't supposed to work beyond certain angles generally no more than 4 degrees and a cardan will double that to around 8 (although I have heard of joints running at 10 degrees but I wouldn't do that).

Two things you need to know are the angles transfer case to prop and prop to dif then verify those.

You can also check the joint alignments the 'yoke' joints should be the same at both ends as in they shouldn't be 90 degrees opposed - if the bearing cup on the prop at the transfer case is pointing at the road then the diff end should do the same or the joints are out of synch.

Make sure that the prop isn't 'over compressed' with the weight on the vehicle too there should be some movement left on the splines.

 

[vib6er]

thanks Benkenobi
prop isn't overcompressed,prop is in alignment-yokes and arrows,prop angle is around 25 degrees from horizontal- 190mm drop from trans box flange. Pls explain line one of your post- are you refering to flange out of parallel tolerances?

 

[BenKenobi]

Yes in a word the angles at both ends must cancel each other out or you get vibration and you can't go beyond the maximum drive angle specified by the joint manufacturer.

Looking for a decent site with images - this is the closest so far Angles

 

[vib6er]

Thanks again
Good site, will digest info and have a think. I,ll chase up max angle from maker, Prop flanges were almost parallel to each other when giving bad vibs, i've pulled the diff nose back up making the flanges more out of parallel and vibs reduced!but i can see where your coming from and i can see more experimentation ahead!

 

[vib6er]

Fookin ell, is there an app for that!

 

[BenKenobi]

No app, not as far as I know.

I haven't posted the complex stuff post your angles and joint specs if you struggle.

 

[vib6er]

Had a few hours to spare today- found app which seems to help if you have'nt got an inclinometer, swaterlevel www.QOOAPPS.com- gives a decimal readout of flange angles, not mega accurate I imagine but it appears to be in the ball park.
Anyhow front flanges about 5 degrees out & rear slightly less, phoned prop company & they suggest I ask Gwn Lewis who very kindly gave some advise, turns out my spring lenghs are 3 inches higher than standard and front prop would be a possible cause- even though she drives smooth with just the front fitted.
So removed front (wide angle) prop and vibs gone again, seems the front & rear are incompatable, swapped the thick end to the trans box when refitting to try & change dynamics and it does seem slightly better- more of a background noise than vibs with a speed range reduction to 45-50. Haven't tried anymore prop phasing cos I've had enough for now!
I recken I'll live with it while saving up for a front carden
PS lateral prop alignment seems slightly out, this will be a player but is it normal on a defender? can't remember what they looked like before I started!Thanks again.

 

[vib6er]

Sorted
bit the bullet and got a carden front prop from gwyn lewis- nice already phased and balanced in that position, grease point on slider aswell- vibs all gone, should have done it straight away!

Got a couple of nearly new wide angle props if anybodys intrested.