Mk IV 1 1/2 litre wheel spinner/hub thread size

(David) #1

Does anyone know the specific size and thread type of the wheel hub/spinner on the 1948 Mk IV 1 1/2 litre (which I believe is smaller size than the 2 1/2 and 3 1/2 litre cars. Looks like 8 threads per inch and perhaps 2 1/4” diameter but I need confirmation.

I cannot find a wheel hub puller to fit, so it looks like I will have to make something to fit and make up a tool to get a problem hub off.

(Robert Wilkinson) #2

I’ve no specific answer but Jaguar was among the first to use standardized Rudge-Whitworth splined hubs. These are specified in terms the OD of the largest bearing that can fit inside. This in turn determines the number of splines, diameter of splines, and diameter of the outboard threaded portion.

If yours is smaller than the common Jaguar size (52 mm) it is probably 42 mm, which is used on most centrelock cars other than Jaguar. These hubs have 75 splines, a 62.5 mm spline diameter, and 59 mm (2.32 in) diameter across the threaded portion. The most ubiquitous thread pitch is 8 TPI but I’ve seen 12 TPI as well. If you estimate 8 then that’s what it is.

Again, I’ve no knowledge of your car (except that it is beautiful) but you might see if the above specs look reasonable.

(Ed Nantes) #3

42mm splines were very comon on what one might call ’ light sports cars’ MG come to mind but there were lots of others
MG Used coarse threads right up till the change to fine threads was made I think sometime in the MGB era.
I don’t know about pullers on MGBs as at least the MG TC had splines on the hub , not a taper.
For my new car with 42mm hubs, I bought a set of new MGB knock ons, partially because they were cheap. and partially because second hand ones can be dubious. If someone has used the knock on to try and remove a hub in the past by hitting the inside of the ears, it’s pretty likely the taper has been distorted. And instead of holding the wheel by the taper, it’s only held at 2 points at 90 degrees to the ears.

(David) #4

It’s really the outer thread size of the hub shaft end (or inner thread size of the Spinner itself). I think I will need to either find a big engineering nut or have a machine shop make me one from which I can make up a hub puller. I can’t find the right sized Jaguar tool in the UK for my smaller 1 1/2 litre hub, and as you say Ed MG had tools for similar hubs (Churchill 18G363 for the 12tpi thread and 18G1032 for 8tpi) - again they are like hens teeth to find in the uk at the 8tpi and I just cant get hold of one.

I was going to use a Spinner to convert into a puller but I thought that one sharp hit on it to try and release the hub if I had drilled out the centre to fit a tightening bolt would probably shatter what seems to be a metal casting rather than engineered steel. I can buy MG spinners rather than use my belovered MK IV originals if needed to chop up!!

(Ed Nantes) #5

I doubt the MG knock on would shatter as they are hi tensile brass, could bend of course. But there should be cheap tired ones around to convert.

(Peter Scott) #6

The face of a spinner would probably be too thin for a thread but you could braze a big nut onto it or simply mount a nut on the inside along with some big washers to spread the load.


(Ed Nantes) #7

Sounds good Peter- and add extra characters forthe computer

(Rob Reilly) #8

Doesn’t this kind of hub puller work?

(David) #9

I will try some MG spinners and put some strengthening on them first - perhaps the lowest cost option.

Unfortunately Rob I’ve the same puller type - but the shape of my wire wheel hub fouls on the back of the legs and you can’t connect to the studs.

And with my other hydraulic puller (which fits) I cannot get the hub off and cant use a hammer to shock the axle.

I think my only option now (and not to damage the hub) is to attach to the wire wheel hub shaft like the Churchill tools.
(Jaguar puller)

(MG puller)

But as I can’t find these tools to fit the 8tpi smaller hub of my 1 1/2 litre MK IV then it looks like I will need to make a bespoke one myself.

(Rob Reilly) #10

Ok I understand now.

The hubs on my '38 2-1/2 Litre measure 2-3/4" OD x 8 tpi. Which converts to 70mm.

According to this chart at Motor Wheel Service,
that would make them the 73mm OD or 52mm wheel type.

If your hubs measure about 2-1/4" OD they are probably the 62.5mm OD or 42mm wheel type.
MWS has hub pullers for these sizes like your captured pictures.
I believe they are in Berkshire.

Here’s another.

(David) #11

Thanks Rob for the links - my endeavours to get the hub off continues!!