Land Rover Discovery Suspensions: Caster

[david despain]

Moderator edit: We are breaking the locker vs. open and Discovery suspension threads up a bit here. I think it is worth doing, as the discussion is a good one.

What's the advantage of an LSD over a selectable full locker, other than price?

In fact, what's the advantage of any other Traction Adding Device over a selectable full locker? (Other than, again, price, and perhaps kindness to the drivetrain. Oh... and the fact they might not require driver decisions, I suppose).

in keeping with the idea of a rover specific train of thought, one of the more common reasons for going with a LSD, specifically the truetrac, is to help regain a return to center feel when used in the front of a lifted coil sprung rover. since castor is adversly affected when this type of truck is lifted, a cheap solution is to put a truetrac up front. this does not solve the problem of a bad castor angle but it does mask its instability and make everyday driveability better.
a selectable locker would do nothing to help the steering as it would be open on the street at high speeds where the bad castor angles are most notable.

 

[michaelgroves]

in keeping with the idea of a rover specific train of thought, one of the more common reasons for going with a LSD, specifically the truetrac, is to help regain a return to center feel when used in the front of a lifted coil sprung rover. since castor is adversly affected when this type of truck is lifted, a cheap solution is to put a truetrac up front. this does not solve the problem of a bad castor angle but it does mask its instability and make everyday driveability better.
a selectable locker would do nothing to help the steering as it would be open on the street at high speeds where the bad castor angles are most notable.

Interesting reason! I don't like the "solution" at all, but I can see the logic of the argument.

 

[david despain]

Interesting reason! I don't like the "solution" at all, but I can see the logic of the argument.

until realitivly recently in the lifespan of coilers there wasn't really any other solution at all. now you can have your swivel balls redrilled by RTE. (thats rovertym engineering http://www.rovertym.com/ for you teriann )
I don't know if there is some one that does this in eruope or not. i don't know of anyone else in the US that does this although it is possible.

 

[teotwaki]

Hmm? Did anyone imply you weren't welcome to comment?

Please read post #132

"Personally, I think that for the thread to work it should either be cleansed of postings covering non Land Rover vehicles......." or moved

 

[gjackson]

now you can have your swivel balls redrilled by RTE.

Or install castor corrected radius arms and a new DC front prop shaft. I'm pretty sure that Scorpion offers those in the UK.

cheers

 

[Hank]

I'd much rather have the re-drilled swivels.

 

[Mike_rupp]

Or install castor corrected radius arms and a new DC front prop shaft. I'm pretty sure that Scorpion offers those in the UK.

cheers

This solution to the caster problem is probably worse than using a Trutrac to mask the problem. When RTE first started offering caster corrected radius arms, they rotated the axle back so that the caster was back to spec. The problem with this is that when used with a DC shaft, the pinion angle would be too low and the ujoint at the pinion would vibrate.

On a lifted Discovery 1, the best solution to correcting caster is to get radius arms that correct the pinion angle and then redrill the swivels to bring the caster back to spec.

 

[gjackson]

The problem with this is that when used with a DC shaft, the pinion angle would be too low and the ujoint at the pinion would vibrate.

Guess I don't understand that. The whole point of a DC shaft is to allow more angle to get rid of the vibration. And honestly, a bit of vibration with no load (with the standard prop shaft) is much better than the associated steering issues with a non-castor corrected vehicle. I've been running a standard prop shaft with castor corrected radius arms for years with little effect apart from a bad pinion seal.

chears

 

[Mike_rupp]

Guess I don't understand that. The whole point of a DC shaft is to allow more angle to get rid of the vibration. And honestly, a bit of vibration with no load (with the standard prop shaft) is much better than the associated steering issues with a non-castor corrected vehicle. I've been running a standard prop shaft with castor corrected radius arms for years with little effect apart from a bad pinion seal.

chears

A DC shaft has a double cardan joint at one end and a standard u-joint on the other end. The double cardan joint in designed to be able to compensate for an angle at that joint only. The ujoint end has to be inline with the drive shaft. In other words, the pinion angle has to be the same as the driveshaft. If not, the ujoint will vibrate.

Right now I'm running RTE radius arms that were corrected for the pinion angle. This brought the axle back down about 3-4 degrees which improved the caster. I'm still a few degrees off on caster, but its much better than before. I'd rather deal with the caster being slightly off than deal with a blown u-joint on the trail or killing a pinion bearing.

 

[Scott Brady]

 

[michaelgroves]

That good looking piece of kit presumably doesn't require the opposite flanges to be parallel with each other, nor in line with each other?

 

[TeriAnn]

Lovely, but what kind of a vehicle is it for? It is something you pretty much never encounter with a Series rig unless it is jacked up a few feet. LR coiler? Jeep?

 

[Scott Brady]

yes, and zero vibes...

 

[Mike_rupp]

Scott, while I don't have a double double and therefore don't have any direct experience with them, I'd avoid using one if there is another solution present. The double doubles are quite heavy and will stress the pinion bearing more than a standard double cardan driveshaft.

IMHO, the best front end setup on a 3"+ lifted D1 is having radius arms that correct the pinion angle, drilled swivels, and a double cardan driveshaft.

 

[michaelgroves]

The double doubles are quite heavy and will stress the pinion bearing more than a standard double cardan driveshaft.

Hmm, no heavier than the rear prop on a LWB, I'd have thought? Out of balance, the greater mass will stress the bearing, of course, but I can't see the weight doing it.