Thread: Caster Corrected Front Swivels, How to do it...

Originally Posted by 350RRC

On a RRC every 1/2" of lift causes a loss of 1 degree of caster. They have 3 degrees to start with. I put up with the shopping trolley effect from a 2" lift for years before rotating the swivels.

It makes a huge improvement to driveability and it is not hard to do yourself.

DL

Hi, I've long been aware of this issue but until recently my Disco hasn't been too bad. Why is it suddenly an issue after all these years. Is it castor or is something else making it more obvious (rear a arm ball joint, for instance).

I had a period a couple of years ago when it was tram-lining badly etc and changing the steering box seemed to correct it. Now it is the worst it has ever been.

Any views most welcome.

Thanks

Cheers

Jim

Sclarke .... Brilliant post ... Trouble is that it gives me more Q's than I wanted
In the picture of drivers side ... you rotated Anti clockwise?

Bush65 .... I get what your saying ... Can you clarify

... // Hence .. For a front RRC diff ....

IF the front diff is turned to give the uni joints on the Diff & the T/C the same degrees .... so the propshaft must be set "out of phase"

IF the front diff uni joint is straight & the T/C is bent .... the propshaft is set "in phase"

Mcrover .... The problem with moving the spline to "out of phase" is that if it was balanced in phase .... you could upset the balancing // so you fix 1 problem ... but score a different one /// but give it a go

Rovercare .... Hardi Spicer set up my front "out of phase" propshaft 29degrees or 2 splines off (Sort of 1/4 turn) // Is this gonna be a contributing problem to funny vibrations
I have tried different positions with varying affects


350RRC .... Thank you for that info ... gives me a formula to work with


I appreciate your info ... and trying to make it apply to my RRC setup .. so I can get it right as you know it's a hard area to sort out as not even LR could sort out properly ... that big steel dampening weight might give the hint

Mike

Check all the steering links, wheel bearings and the like and then the radius rod bushings and if all looks good then I would consider that you may have bent something.

The thing is, from what I have heard, you need to go more than 2.5" to 3" to be effected in most cases from lack of CASTER (I recon ive got it right htis time Matt) so I would think that if it is something that has slowly become a problem then it is more than likely a wearing item that needs looking at.

Originally Posted by sclarke

Slotted....
and extra holes drilled as locking bolts so they wont rotate back

sounds good,as long as theyll fit a late series 1 disco,im interested,as i can fit them when i fit lockers.cheers,Ramon.

Originally Posted by discologist

sounds good,as long as theyll fit a late series 1 disco,im interested,as i can fit them when i fit lockers.cheers,Ramon.

No they will not, as clarkie would know, thats why he's selling them, yours will also be 7 bolt

Originally Posted by rovercare

No they will not, as clarkie would know, thats why he's selling them, yours will also be 7 bolt

Exactly, unless you replace the diff housing as well you need a set of 7 bolt.

So the 6 bolt i have suit pre 85 RR

Originally Posted by pug303

Hi, I've long been aware of this issue but until recently my Disco hasn't been too bad. Why is it suddenly an issue after all these years. Is it castor or is something else making it more obvious (rear a arm ball joint, for instance).

I had a period a couple of years ago when it was tram-lining badly etc and changing the steering box seemed to correct it. Now it is the worst it has ever been.

Any views most welcome.

Thanks

Cheers

Jim

Can be a number of issues, including:
Swivel bearing preload (lack of correct preload).
Pan hard bushes
Radius arm bushes
Tie rod ends
Tyres
Wheel alignment

Originally Posted by mike 90 RR

...
Bush65 .... I get what your saying ... Can you clarify

... // Hence .. For a front RRC diff ....
...

Sorry not sure what you want here.

Originally Posted by mike 90 RR

... IF the front diff is turned to give the uni joints on the Diff & the T/C the same degrees .... so the propshaft must be set "out of phase" ...

Sorry I can't make too much sense of this.

In the 1st part are you asking about rotating the front diff so that it will be at the same angle as the t/case?

Stock castor is 3 degrees.
Stock angle of front diff pinion is approximately 12 degrees (from memory) up towards the rear.
Stock angle of t/c, I haven't measured - my guess is 5 to 7 degrees down toward the rear.

Now, to make the front diff pinion parallel with the transfer case, you would have to rotate the front diff assembly 12 + 5 to 7 degrees (approx 18 degrees.

Then you would need to make the u-joints in the front tailshaft in phase so they don't vibrate.

You would also have to rotate the swivel balls forward approx 18 degrees to correct the castor angle.

Lastly but not leastly, you would have to find some u-joints that can operate at high angles (the stock ones won't come close) - remember when the diff pinion is rotated down it make the angle of the tailshaft much steeper.

The other problem you would find is that the tie/track rod would be much lower than the axle housing and would be damaged easier.

Originally Posted by mike 90 RR

... IF the front diff uni joint is straight & the T/C is bent .... the propshaft is set "in phase" ...

Sorry, again I find it difficult to understand what you are asking.

I probably had a glass of wine before I made my previous post that you are questioning, but I thought it was reasonably straight forward.

If you disagree with, or can't follow something I said in that post, please quote the part/parts in question - don't put your words in among mine and hope that I can decipher them (it only confuses me as to what you are inferring).