Lower front upright bushes

[erictharg]

On inspection the slight play in my front wheels is not the king pin bushes. They're still nice and tight - which makes sense given the "better than the average Midget" environment they've lived in, and very regular greasing. The problem lies with the pivot arrangement between the bottom of the kingpin and the lower wishbone. Whilst the brass bushes Westfield provide are nominal 9/16" od, the bore in the kingpin is already well oversize (+0.006" on my car) and has a poor surface finish. Result is that they are loose and get looser as they wear.
I think the best option is to machine out the kingpin bore to 21/32", allowing me to fit a 9/16" ID Glacier DX type bush (acetal lined) and make up some new steel wear sleeves to the same dimensions as the Westfield brass items. Should restore the working tolerances to something sensible and give easily replaceable, low cost, bushes. Not sure yet if I'll stick with the Westfield standard acetal / nylon thrust washers or use the DX type.
Anyone had similar problems with this area of the car?
Jan - you must have encountered it with all the miles you've put on yours.

[Westfield 129]

Yes, I have, with my early LHD car.

I have a little play there as well, but the setup for the earily chassis is a little different than the new car.

The old one has the lower trunion bored with some brass bushes, while the new car's kingpins are not bored and use a Westfield provided sleeve and delrin thrust washers. There were no modifications needed when I assembled that car with new uprights and king pins. Evidently, there is some hammering going on there, likely as the fit after amateur drilling was not precise.

I ordered and received the new parts, but I have to replace the king pins to use them. They are for the new car... I didn't specify when I ordered.

You could just clean out the bore of the lower trunion, then have some new brass (or bronze) parts machined to fit. You could also use Delrin, with a sleeve. Keep it lubricated, and it will probably last forever. I probably would not add any additional compliance to this area of the suspension by using a rubber type bushing. You could use brass, bronze or delrin thrust washers. I have considered doing this. This would not be silly expensive to do, and for not much more, you could make a spare set. That should carry the car into the next century.

I am planning to replace the uprights with a new set of 4340 spindles, so I will be using the new parts from Westfield, and new kingpins to go with the new 15" wheels. This is the last piece of the car that I have not replaced in the chassis.

Your idea sounds like a good one. Whichever way you go will fix the problem, permanently.

I have tightened and greased the old parts on my car and the play is not really excessive for the moment. Steering and tire wear is good, and the alignment settings have been stable. I am hoping to order the new uprights, with fitted king pins, in about a month.

[erictharg]

I did consider boring / reaming out the kingpin and making up new brass bushes to suit, but I'd just end up with some wear in the kingpin bore eventually as it is not hardened. I practice a little play is not a big deal - it is always under load from the spring anyway and the tyre is not going to notice a few thou of movement! I'll see how the DX bush solution goes.

[Westfield 129]

Not the king pin, but the lower trunion where the kingpin attaches to the lower arm. Westfield used two setups for this. When I requested the parts to renew this joint, they sent me parts from the new model, which uses a standard kingpin lower trunion, which is different from the old chassis, which required that the trunion be drilled to fit the bushing.

My uprights have pressed in bushings for the kingpins, and are reamed to fit. So far, no wear problems when kept greased.

[erictharg]

Modification done as previously mentioned. My local machine shop drilled and reamed out the bore in the foot of the kingpin to 21/32", being careful to follow the original bore (it is angled relative to the king pin to allow for king pin inclination). They then made up a pair of wear sleeves to the same dimensions as the Westfield brass items. All assembled with 9/16" bore DX bushes and of course I can tell no difference at present! Time will tell how they wear. Even if they last no longer than the original set up the bushes are only 60p each to replace! The new track rod ends I got are as stiff as the old ones. Think I'll opt for the Peter May rose joint track rod end set up when I can afford it.

[Westfield 129]

The stiffness in the rod ends will go away with time, but in any case, should not bind up the steering. My guess is that your binding problem is coming from somewhere else. I would go through a comprehensive front end setup, and check everything from the column to the rack, and the king pins for binding.

I use new, very tight tie rod ends, and have no problems with friction. While the rose jointed setup is good, it is not really any better than the rod ends, and you do have to be careful about the bump steer setup.

The bushing should not be a problem.

[erictharg]

I don't have a problem with the steering binding, Jan. I was just that in such a light vehicle it would be easy to compromise steering feel with something as minor as stiff track rod ends. You don't notice anything untoward when driving. I might look at replacing the stock bronze thrust washers at the top of the kingpin with DX versions. The stock arrangement is difficult to keep well lubricated, and it carries all the suspension load.

[Westfield 129]

I have not had any problems with kin pin wear, as the W11 is quite a bit lighter in front than the MG Midget 1500 that those arms were used on. Mine are original, and are very old, yet work just fine.

The rod ends wont make any difference. as I have tried both spherical bearings and the conventional tie rod ends. Both are tight when they are in good shape.

In addition, good rod ends are extraordinarily expensive. The only ones that last well in the rear suspension arms cost the better part of £60 each. Less expensive ones don't last long, and develop play when they spit out their teflon linings. Good steering acuity is maintained well with the standard units, and they are inexpensive.

Fortunately, the W11 doesn't have much of a bump steer problem when the ride height is set properly. The real advantage in the spherical rod ends is the ability to make changes to the bump steer settings. That may improve the steering, if you feel that it needs improvement.

I have had everything here from a TRex to an early 7 series 1 that weighed a scant 400Kl, with road equipment ,and half a tank of fuel. None had anything that resembled compromise. You could drive over a dime, and tell heads/tails and the date. The cars have had tires ranging to 15" wires on the 7 (standard equipment for the "America") with the racing Dunlops, to the 185/70/13s on my LHD 11 with the 30 year old kingpins and thrust washers.