propshaft vibration and pulsing

[evang]

I have a recently pruchased a 1995 300 TDI disco which has the following mods 265 tyres (mud), scorpion 2 inch lift kit, a winch c/w bumper, split batteries and steering protection. All at the front.

The disco pulse/vibratates at around 40mph to 45mph worse in fifth gear than forth. It does not happen with the front prop removed. I have had the standard prop checked and its ok.

The out put shaft of the transfere box feels ok as does the diff end.

It now really does my head in.

Having borrowered a front Double Carden disco 2 prop and flange the problem has dissappeared by 50%. But still doing my head in.

I have been told that this would solve the problem. But other people have said all you need is caster correction arms. These apparantlly will make angles for the standard prop U/J's correct. Other peolpe say with caster arms you may require a Double Carden disco 2 prop???

At the moment the diff u/j angle on the Double Carden disco 2 prop is not  say with in 3 degrees as some say is required for the prop to work correctly. Will the castor arms sort this. But what if the castor is 1.5 degrees out and i fit 3 degree arms any only ideas???

The other thing the disco sits higher at the back than the front by a bout 2.5 inches along the body line. Is this normal with a lift and a winch fitted.

Therefore not having another disco to compare suspension heights with for caster angles etc. Do I buy caster arms or new springs

Cheers Lads any help would be most gratefull.

[Budgie]

I need to have a good think about this one..... :-k

The fact that the vibration goes when the front prop is removed doesn't necessarily mean that it's the prop that's at fault, this is backed up by replacing the prop with the Carden prop and the vibration is still there, although reduced.

Do you get any wobble through the steering as well as the vibration?
If so, then check the wheel bearings, swivle housing bearings and C/V joins for ware.

The caster correction radius arms will require the Carden propshaft as these arms increase the angle of the U/J on the transfer box end of the standard prop, causing it to vibrate and pulse. (Are you sure you don't already have these fitted!!   ) This is turn can wreck the transfer box output bearing if not resulved.
The main reason for putting the caster correction arms on is beacuse the vehicle is wandering all over the road, "tramlinning" and generally difficult to control as a result of lifting the suspension. The arms bring the steering back into it's standard spec.
A 2" lift will not normally create these problems, only +3" and above.  

The fact that the vehicle sits higher at the back could be because the previous owner didn't componsate for the weight of the winch when ordering the springs. You can get uprate +2" spring that allow for the extra weight of the winch & bumper, if this hasn't been done then it will sit down on the front end.  

I'm sure other will be along to assist, try also doing a search for caster correction radius arms and carden props, there are a few good threads on here about these subjects.  :D

[chuggaman]

castor corrected radius arms are generally the only reason why you have to fit a double cardon prop.

if you have the standard radius arms and a 2 inch lift you should not get severe vibration through the front prop unless there is another problem(transfer box out put shaft)

are you sure it is only a 2 inch lift

check the radius arm bushes to make sure they are not offset(as you can buy these to correct the degree of castor correction)

also dont rely on the fact that your "borrowed disco 2 prop" is balanced and rhe flanges are corectly set

mike

[Range Rover Blues]

I dissagree.  The pulsing will be there, I'll put money on it.  It depends on many factors as to how/if the results can be fealt, backlash, bush stiffness can all play a part in transmitting or absorbing the rumble that results.

The Cardan jointed TD5 prop is a clever peice of kit, but you need to be able to understand what is happening fully and it's difficult to explain.  ANY UJ will cause pulsing, the effect increases proportional to the sine of the angle (I think) so small angles do little, say up to 3 deg, but 6 deg causes big problems.  The trick is usually to have a pair of UJs, both at the same angle and in phase, so that one absorbs the pulses caused by the other, the propshaft tube pulses but the output and input do not, problem solved. :)

This is true for the front end of a LR, even though the diff pinion is not parallel to the gearbox output shaft, the UJ angles match and all is in phase.  Clever, as the UJ angles are reduced compared to say a series front prop.

Lift the front by 2" and the top UJ only increases by 3 deg and the steering catsor becomes zero (the axle rolls on the ends of the arms), but as the ujs are both at similar angle the pulsing is almost "cancelled out" or absorbed, not entirely but almost.  Depending on that condition of your car, you may decide to live with it.

Fit castor correction and you straighten the axle UJ out, so it can't abosrb the pulsing, plus you increase the gearbox UJ by about 1/2 degree making the pulsing worse, double whammy, you loose both ways making the car hard to live with.

This situation is ideal for the TD5 prop, the axle UJ has nothing to do and the CARDAN or double UJ joint forms a CV joint, a pair of UJs are matched, in phase, thus absorbing any pulsing internally.  The large cast ring in the middle of the joint is the only bit that pulses.  In addition the joint angle is shared between the joints so reducing the pulsing effect (6 degrees now =2 lots of 3degrees).  As a bonus a Cardan joint can drive at almost twice the angle of a UJ.

Now, if you fit a TD5/Cardan/double UJ prop to a car without castor correction, then you have the CV joint at the top end, great, but the axle UJ is still driving through about 3degrees and so puts in a whole new load of pulsing (remember it was absorbing the pulsing on a standard prop) which expalins why the Cardan prop only works with castor correction.  The 2 mods should be seen as a whole package, like the springs/dampers should.


Please say you understand now, I can't think of how to explain this any easier without visual aids.

[evang]

Cheers Lads who have replied I have ordered castor arms and hopefully fit them before xmas or on xmas day if the wife will let me. Also I will be leaving on the DC prop and and hopefully this will totally cure this vib

The problem is caused by the lift and landrover build tolarances made a nightmere by the methods of repair and who tells you what to buy as in parts shops owners. Solution i thnk is can you live with the vibs?? or are you fussy like me. Then get castor arms first to reinstate the steering angles even if your steering is not vague. then still getting prop vibs or rumbles then the disco 2 DC prop.

After researching the internet some lifts seem to result all sorts of diffferent vibration problems and some lifts have none. Landrovers Hey!!

I will post my findings what ever happens

[evang]

I have now fitted the castor arms and all the vibration / pulsing has all but dissappeared. Iam leaving the DC prop on as this type of prop is design to limit noise, harshness and vibration. The disco is now much more driveable.

To level the disco out  and not knowing if the springs on the front have sagged due to the winch etc or the rear ones are to allow for extra weight.

Does any one know where to get 1 inch spacers for the front springs. Or any other ideas!!!!

Cheers

[Budgie]

Wizard, another Mud-Club member has these on Ebay at the moment and can also supply them from his website: http://www.wizardbilt.com  

[evang]

Cheers

Agreed a price of £25.00 for two 1inch spacers with bolts and packing with Gerarad from wizard.com

Hopefully these will make the disco level. Scropion Racing have said the existing springs are correct and the front will dip with all the extra wieght!!!

Merry Xmas All

[Budgie]

If the front springs droop with the extra weight then they ain't the right springs.

Other firms will supply a +2" spring that will sit the vehicle level without a winch and a different rated +2" spring for those with a winch & bumper fitted.

I'm sure someone will correct me if I'm wrong.  

The 1" spacers should do the job though, glad Wizard got you sorted.  :D

[muddyweb]

If the front springs droop with the extra weight then they ain't the right springs.   <snip>  I'm sure someone will correct me if I'm wrong.  

You aren't wrong at all...  

If the front is too low "due to the extra weight" then the springs are simply not correct for the vehicle.

[evang]

Following futher research on the net and after visiting this web site www.4x4ag.com/html/sr_ome_coil_springs.htm which tell you what application of scorpion springs fit what.

From the recite from the orginal kit from Scorpion I have what looks like non winch front springs (SR32 + SR32.5) and need two other winch type ones (SR12 + SR12.5)!!! .

I quoted the original references numbers from the recite to Scorpion but the chap I spoke too insisted the springs here o.k

I think I will phone Scorpion again on Wednesday

As I want this disco set up right as its my every day car.

Who's Knows if I has susssed out the springs first I might not of had vibs and saved £430.00

For Propshaft Vibs and pulsing and the transfere box and front diff are o.k

First Step Check your springs. Determine your lift. Level your vehicle if required.

Still having Propshaft Vibs and pulsing and/or tram lining /vague steering
2nd step fit castor correction arms

Still not happy after extensive road tests
3rd step Disco 2 DC Prop

Possibly the utlimate set up with a 2 inch lift is castor correction arms + a Disco 2 DC Prop this hopefully give's peace of mind and a empty wallet!!!! but this seems to only be required by us unluckly ones as some disco's and LR's have no problems.

Tonite is Chrimbo Eve the TV is poor and I hope Santa is not in my disco as my kids may CRY!!

Cheers

[evang]

While waiting for a reply from Scorpion Racing, who are consulting there spring makers in the new year.

I have now checked the redundant panard rod axle bracket to the chassis mounting bracket and the chassis bracket was one inch higher suggesting the suspension was 1 inch lifted. Instead of 2 inches. This must be due to the wieght of all the kit on the front and Scorpion springs sagging(not winch rated!!!)

I have installed a Wizard 1inch spacer kit on the front and now the difference is two inches.  Yes indeed!!!

The Disco looks alot better but more importantly the DC Disco two front prop angle looks correct compared to others I have seen in photos. Within 3 degrees.

My only concern is the slider on the front prop now extends to far, which may cause vibrations caused by to much slider slip

To counter act this Wizard is going to make me a Propshaft Spacer as detailed on this site, Home page - workshop- suspension - propshaft spacer.

Cheers lads to all who replied.

[evang]

Scorpion Racing are supplying me with two new front springs too give a 2inch lift, at trade price and have said that the orginal 2 inch lift springs 185 Ib rated where possibly not suitably rated for heavy offroading all the wieght on the front!!!!. And said the original purchaser possibly did not mention winches etc or did not have them fitted when he bought the springs.

Any ideas on how to easily fit them as having gas shocks on which push down. As fitting springs with normal shocks on you push the shock up and it stays there and dropping the axle allows easy removal of the spring. Can not be bothered really unbolting everything if i dont have to.

Cheers

[Budgie]

Easiest way, as you have to disconnect the bottom of the shocker anyway, is to remove the turret & shocker in a oner.
It's only 4 nuts and makes life so much easier, although I would have 2 new securing rings standing by just in case.  

[Range Rover Blues]

:D

Been there, snapped that.  Get the HD ones from Paddocks, rude not to at their price, proper bolts welded to a steel ring, not the cheese ones that OE parts are made from.  I sheared off a brand new one last year, they are poo.

[Tyke]

Yeah -  sheared a couple of bolts off my rings a while back when I installed the lift.

Lucky you lads had warned me . . . had a couple of new ones standing by and that saved me some some heartache