4AD Singer Kingpins

[Stephen]

Happy & Safe New Year everyone...Kingpins on my 4AD are showing signs of wear, and I would like to replace them before they get worse .. is there a replacement from another model Singer or make of car that can be used ..has someone an old set they have removed that they can measure and supply me with the dimensions, as we have a supplier down here who is willing to check his warehouse of NOS to try and match them ..

Regards
Stephen

[kabu]

Hi Stephen,

I think the kingpin on the 4AD is specific to Singer as it has the lower wishbone fork integrated to the part. It is not a simple straight axle as in some other cars. I should have a worn out set separate and can take measurements from that for you.

Regards,
Pekka

[Stephen]

Hi Pekka,.. Thank you for the response .. I have been looking at a 4AB front end diagram in the manual and it looks like the bottom is attached to the kingpin although it is not very clear,.. they call it a swivel Pin ?? here is a quote from the manual page 6(G) 7... " Remove the nut and washer from the cotter pin which secures each swivel pin through the axle beam, knock out the cotter pin and withdraw the swivel pin, thereby releasing the axle " unquote.
Just wondering if I take the cotter pin out of the top nut and tighten the "swivel pin" a bit more if it will help ? and I thought I read somewhere that there is an adjustment for the pins?.
If any one has had experience with the "swivel / king pins", please let me know, any help would be appreciated..

And Pekka, We have a company over here that tends to go out of there way to help supply hard to get parts, and they have a warehouse full of old stock. They have offered to look for a compatible set of kingpins if I can supply him with a photo, drawing and measurements..
if you can help out it would be appreciated, a photo with measurements would help if you have the time.

Regards
Stephen

[kabu]

Hi Stephen,

Here is an exploded view of the 4AD front suspension - http://www.singercars.com/4ax/pnine.html

And here are some pictures and dimensional information about the 4AD kingpin.

4AD Front Hub

4AD Kingpin

4AD Kingpin 2

Kingpin Dimensions

The kingpin shaft is 3/4" in diameter and it seems that it usually wears out on the lower bush area and that causes excessive play on the lower part of the front hub. I actually had this problem also and by investigating the construction I found out that the lower 7/8" diameter area for the kingpin bush is actually so long that it enables moving the 1 1/4" long bush upwards about 20mm so that the upper part of the bush is on the unworn part of the kingpin, see the illustration below. This seems to cure the excessive play quite nicely.

Moving Kingpin Lower Bush

If you need new kingpin bushes, they are 3/4" ID, 7/8" OD and 1 1/4" long.
http://simplybearings.co.uk/shop/p12010 ... _info.html

Hope this information helps,
Pekka

[kabu]

Hi,

One more comment about the crown nut on top of the hub. That nut controls the axial play of the kingpin and tightening that does not help with the radial play that is usually the problem. Over tightening the crown nut just makes your steering stiff.

Regards,
Pekka

[Stephen]

Hi Pekka .. Thanks for the detailed information, and the info about tightening the castle nut on top, because that was the first thing I was about to try ..

It seems that the best way to go about it, is to start by moving the 1 1/4" long bush upwards by 20 mm to see if it helps with the problem ..
I have forwarded the diagrams and photos of the kingpins to the interstate vintage & classic car part supplier, and if he comes back positive with a match, then I will post details on the forum,... but looking at the photos, I doubt very much if they will be able to help ..

Thank you for going to all the trouble of posting this information on this site, I am sure this information will help other Singer owners with this problem and those further down the track, that will experience this problem with their kingpins..

Regards
Stephen

[kabu]

Hi Stephen,

There are couple of things to consider here:
- What is the condition of the kingpin bushes, If the excessive play is due to worn out (lower) bushes, moving the lower bush upwards does not help, you need to have the bushes in good condition.
- If you know the bushes are new or checked to be in good condition, you can compensate the worn out kingpin by moving the lower bushes upwards so that top part of them is away from the worn area on the kingpin.
- The bush length is 1 1/4" but the 7/8" diameter area for the lower bush is significantly longer than 1 1/4 (at least it was on my car) after that the ID gets larger in the middle of the hub carrier, as I tried to show on the illustration. If you do move the lower bushes, check how long is the 7/8" diameter on the hub carrier and move the lower bush up only so much that the top end of the bush is where the 7/8" diameter ends. This is to give the bush the required radial support all its length.

If you don't know the condition of the bushes, I sugggest you replace them just to make sure.

Regards,
Pekka

[Stephen]

Hi Pekka .. Thanks again for the info,.. have ordered the bushes, and when they arrive will proceed with your suggestion ..

One other front end query.. I have replaced the front wheel bearings ..Between the the inner and outer bearings there is a spacer with a tapered end, the tapered end goes to the outside of the hub, but my question is ... does this spacer lock up between the bearings and have no movement ?..... ie, inner and outer bearings place pressure on the spacer to prevent movement..
My spacers are loose inside the hub, and I have a scraping noise when I turn hard right, .. checked backing plate, brake pads, brake springs adjusters and everything there is OK and just wondering I have to try and press the bearings in a little more, although they seemed to press right up to the shoulders in the hub ..
Styephen

[kabu]

Hi Stephen,

I have not experienced similar problem on the front wheel bearings but I guess it might be possible that the noise comes from the bearing spacer being loose between the bearings. If that is the case, it may be because of the bearing specification or dimensions are not exactly correct. Here is one article about that subject on MG front hubs http://www.mg-cars.org.uk/mgcc/midgetre ... ings.shtml

Just out of curiosity, did you get the kingpin play corrected?

Regards,
Pekka

[Stephen]

Hi Pekka .. thank you for the information .. I sent the detailed drawings off to an interstate car parts supplier, who has a warehouse full of new Old Stock, of hundreds of models of cars, and he says it will take them years to identify and label all the parts .. so he will be sometime before he gets back to me on whether they have any NOS kingpins in stock ..
To answer your question whether I have done anything about the kingpin adjustment .. the answer is no..Reason being is that the last few weeks have not been Garage working weather ..

We are having a heatwave with temperature's consistently in the mid 30's and often into the low to mid 40's, and I do not mean Fahrenheit ..
The paint tins are popping their lids it's that hot.

At the start of the heatwave I did manage to sort out the wheel bearing problem .. very much in line with the MG link you sent .. the new wheel bearings are a smidgen under size, from the originals, so a mate of mine turned up a couple of washers 2 mm thick and we placed them between the inner bearing and the seal, which allowed us to tighten up the wheel bearing tight without it binding.
No matter how tight the bearings were pressed in, they will only go to the lip that is manufactured in the wheel hub, and the spacer inside will always have a little movement... I located a set of 4AB front hubs, and pulled them apart to find that the spacer also had some movement in it.

I will probably drive the car as it is, as the movement in the kingpins is very little, and when the winter weather gets here, I will can lay the car up and work on it in cooler temperatures .. usually our winters have daytime temperatures in the mid to high teens ..

Thanks for your help, and when the kingpins are done I will put a post in to let you know the results ..

Regards
Stephen

[tnandy1]

Hello. Have you resolved your king pin issues yet? I have a 1954 4AD I am parting out. The odometer shows less than 6000 Miles. I believe this to be accurate mileage. In talking with a guy about this car he remembers seeing the car sitting not running in 1960. So 6000 Miles in less than 6 years is probably correct. Anyway I will look into them today and let you know what I learn. They should be no problem to remove since I already had them off. I had sleeves machined for the Singer spindles to accommodate a set of wire wheel hubs off another car. Andy

[Stephen]

Hi Andy .. I have sent you a PM .. Regards Stephen