Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing King pins - acceptable wear?

I am installing the front Suplex suspension, so I could measure the wear of king pins (KP).

The car (2009 +4) has 15000 km now.

There is a noticeable clearance on the bottom bushing (disassembled, dry without grease). However, much less to feel (but you can notice) when moving the wheels at the top/bottom, assembled, jacked front.

The KP/bushing max. ovality at the bottom end is approx. 0,1/0,2 mm.
KP: 25,28min/25,38max mm bushing: 25,68max/25,48min mm 2 measures with 180 deg difference in the most worn area of KP, the first measure is left/right (most friction and wear) and the second front/back orientation. Hence, the largest clearance KP to bushing is also around 0,4/0,1 mm (dry, without grease). Turning the KP for 180 degrees, the clearance on the critical friction places (bottom end, inner/outer side of the KP/bushing) would be then slightly reduced to around 0,3 ( left/right of the KP), however increased 0,2 mm front/back).

Is this still acceptable? I have no experience so far what are "worn" KP.

As I understood (GoMog), the standard factory KP clearance is 0,005" (=0,127mm).

Many thanks for advice/comments!

Peter

I have installed The front Suplex suspension last year in july on a 2005 PLUS 4 originaly with Devol bushes and changed them with bronze bushes.

The new chromed king pins had a diameter of 25.50 mm and the Librand reamer has a 25.63 diameter leading to a clearance of 0.13mm which is consistent with the clearance of Gomog.
In term of mechanical engineering it is a big clearance, but seems to be necessary to avoid sizing. By exemple H7g6 which is the most common in precision engineering provides 0.007 to 0.04 mm clearance for the same diameter.

Have a look to my old worn KP:

http://www.talkmorgan.com/ubbthreads.php/topics/476047/Re:_Calming_the_front_suspensi#Post476047

On this photo the initial diameter of the KP was 25.50 and the wornest part is 24.50 mm after 50 000km (-1mm). There was no problem with the driving, but I am not a pilot.

The only problem is the new run-in. Your KP and bushes had a relative position. If you do now the re-assemby, the KP and bushes will not have exactly the same position leading to a new run-in and surely of an accelerated increased clearance.

The best would be to change the KP and bushes, but you can try to re-use your old parts. With the SSL (SUPLEX) suspension there is less compression for the assembly and it is easier to do it again.

Great post...

It's so subjective but if it were mine I would want to replace them.

Whilst on the subject of sizing has anybody taken there own fairly  precise meausment of the tube I/D on a post 2007 car please? 

If you have to use a reamer, with bronze don't lubricate, but exceptionally you can use water.

I did mine last year with the Suplex (SSL) Suspension and used new chrome king pins and bronze bushes.

I also used the Librands reamer and the clearance was just about perfect, perhaps very slightly on the tight side but this allowed the pins and bushes to bed in nicely over the first few hundred miles.

In my view, if you are changing the front suspension to Suplex you should change the pins and bushes at the same time.

The hard chrome pins also have slightly less friction than either mild steel or stainless steel so the suspension works better after they have bedded in a bit.

I'd draw the line at using water to lubricate a kingpin reamer. Not unless you want to ruin your reamer.

I've always used a light oil on phosphor bronze as it both lubricates the cutting flutes and also washes away the swarf.

I also keep my reamers protected in my tool chest by using a piece of 22 mm foam pipe lagging as a sleeve.

Arwyn

I use paraffin sometimes.

Arwyn[/quote]

I use paraffin sometimes. [/quote]

"Esso Blue" I hope

Had a workmate who always washed his car ln paraffine, looked remarkabley good for a period afterwards.