Caster kit

[Jens Munk]

It has been mentioned several times that Rover released a "caster kit" in the early 70'ies to improve the steering self-centering. I am curious and wonder if anybody has the Rover documents on this? Or just some pictures of the kit?

Thanks,

Jens.

[enigmas]

Here's a re-post of the original Rover Factory method of increasing caster.


Jun 3, 2014 at 10:46pm

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Post by enigmas on Jun 3, 2014 at 10:46pm

It's actually very easy Steve. Think about this. If you can move the top wishbone ball joint to the rear a bit you'll add some castor.

View it this way. Look down at the DS top wishbone (like you were superman and had xray vision!)

Place a 1/4" spacer between the right hand (RH) wishbone outer end at the ball joint.

Then fit a similar sized spacer at the rear (where the bush is) of the LH top wishbone. Yes, the nut won't go on as far.

This mod moved the swivel (ball-joint) back 5.38mm or .212" which gave an increase in caster of approx. 1 degree 2 minutes


This information was made available by Rover in May 1972 under Service Information Vol. No3.

With a bit of fettling (grinding) you could probably fit thicker spacers for more caster.


Read more: roverp5.proboards.com/thread/8300/front-suspension-geometry?page=1#ixzz37GUzVrNi

Read more: roverp5.proboards.com/thread/5450/modified-steering?#ixzz6BlBwzXLF

[Jens Munk]

Thanks!

You don't happen to have the May 1972 under Service Information Vol. No3?

[Jens Munk]

That should be doable. Seems like the bushings are due for a replacement anyway:

[enigmas]

It does look like it could do with some TLC Jens!

Why do you need reference to the document, the quarter inch spacer mod is about as straight forward as it gets.

[Sam Bee]

Having read all that, including the references, I need clarification. The instructions refer to 'DS top wishbone' - should that be O/S, i.e right hand side of the car?  Then we have '... right hand (RH) wishbone' - so given that we are talking about the right hand side would this be the front wishbone. If so that would be much clearer and not lead to error. 

[Jens Munk]

Jan 22, 2020 13:17:30 GMT enigmas said:

It does look like it could do with some TLC Jens!

Why do you need reference to the document, the quarter inch spacer mod is about as straight forward as it gets.

I am mainly just curious to see the original caster document. And then, it may be a little more complicated than some simple spacers. What about the shoulder on the stud fitting into the link arm?

Took the top links off to inspect that bushing, and it was just in time. No wonder it was rattling on speed bumps.

[enigmas]

Sam...perhaps it's easier if the reference was made to the front and rear of the car as the forum has an international audience...and also that the cars are RHD and LHD.

Using the above to clarify, the rear wishbone is the one to modify.
Fit the spacer on the rear inboard pin.
See diagram below.

[Sam Bee]

Thanks Enigmas. Much more clarity with a diagram.

[enigmas]

Jan 22, 2020 22:38:28 GMT Jens Munk said:

Jan 22, 2020 13:17:30 GMT enigmas said:

It does look like it could do with some TLC Jens!

Why do you need reference to the document, the quarter inch spacer mod is about as straight forward as it gets.

I am mainly just curious to see the original caster document. And then, it may be a little more complicated than some simple spacers. What about the shoulder on the stud fitting into the link arm?

Took the top links off to inspect that bushing, and it was just in time. No wonder it was rattling on speed bumps.

Obviously Jens you'll going to need a modicum of engineering intiative otherwise just leave as is and live with the original design.

Here's what you could do...a lathe and drill press would be handy.
* Make a 2 suitable spacers (from a mild steel bar)
* Machine the outer spacer with a registration hole that fits over the locating shoulder on the outer ball joint.
* On the other side of the outer spacer machine another locating hole to fit the shoulder on the wishbone or simply grind off the shoulder on the wishbone.

[johnwp5bcoupe]

I like that idea of making a washer Vince

I can make a set for one member if they give me dimensions "no charge" for members PM me

[enigmas]

Here's a little tech drawing with dimensions for the adventurous amongst you...for those who'd like to make their own positive caster spacers.

The appropriate made spacer (3/8") should add between 2° - 3° Positive Caster. Anything is better than the current 0° caster.
This will vastly improve the straight line directional stability of P5Bs at speed.

[johnwp5bcoupe]

I have concerns at 3/8" there will not be enough thread Vince I have a solution but I need to verify it with the components in my hand! if it works you could increase the castor further or at least have a choice!

[enigmas]

No issues with that John.

If they're slightly too thick it's not that onerous to turn them down fractionally more and arrive at a viable thickness. Unfortunately the thinner they are the less positive caster is added.

* AFAIKS there's a couple of option available.

1. I have some 50mm diameter alloy bar that I can turn down to a make suitably sized 'loose' spacers at a 1/4", or

2. Turn down a mild steel spacer oversize (3/8"), weld it to the wishbone at the ball joint end and then recess the area where the nut bolts on to the wishbone or make a recessed stepped nut from some hex bar.

Do something similar at the pivot end of the wishbone as the metalastic bush sits proud (approx 1/8") either side when pressed into its housing.

[johnwp5bcoupe]

Jan 29, 2020 9:46:00 GMT enigmas said:

No issues with that John. If they're slightly too thick it's not that onerous to turn them down fractionally more and arrive at a viable thickness. Unfortunately the thinner they are the less positive caster is added.

I have a idea in the old grey cells Vince once I get the top ball joint and a wishbone

[Sam Bee]

Thanks for additional discussion and diagrams. I can now say that mine was already converted but do not know if the 'official' kit was fitted. The spacers are 1/4 inch. Don't think I would want to exceed this as then more thread would be covered. I suppose that a reduced height nylock nut could be used but would that be sufficiently strong?

[enigmas]

It depends on how you design the spacers and the material used Sam. Refer to my comment above. There are 2 each side (front top ball joint & rear wishbone swivel pin) and they're not the same due to their position and method of fitting.

[Sam Bee]

I am very clear about what is needed. Am happy with the large diameter spacer that I found on the top link. But concerned about the existing arrangement at the top ball join,t so shall machine something up, as suggested on the diagram. Many thanks for the advice.

[Sam Bee]

I have now gotten around to cleaning up my top swivels and discovered one spacer on each. The outside diameter is the same size as the boss and thus locates in the detent in the wishbone. The inner bolt had packing to make up the gap. Thus the wishbone sat 1/4 inch out to match the extra large washer behind the other wishbone at the top link. This all looks to be of some age so is it the original Rover provided kit, or not? 

[Sam Bee]

Attachment DeletedAttachment Deleted

A couple of photos.

[johnwp5bcoupe]

Feb 10, 2020 19:16:11 GMT Sam Bee said:

View AttachmentView Attachment

A couple of photos.

That doesn't look right Sam there should be a 1/4" plate in-between the small spacer should be there for the Wishbone registration, I am looking into 3/8" to 1/2" for a bit more Castor!

[Sam Bee]

The car behaved well with 1/4" but if you try more I would be interested to know the effect on steering, John. Shall leave making up new spacer plates to await your experimentation.