Spare wheel

[Den]

Having had 2 blowouts on my minibus in 3 weeks, first for many years.

Both costing me an absolute fortune in lost revenue.

 

I’m now looking to purchase a spare for our motorhome.

16 inch wheels with 225 75R 16CP tyres. Steel wheel.

In adverts I’m looking at it mentions

5 X 130 PCD

AND

5 X 118 PCD

 

Both 16 inch wheels and both by the look of it for my 2019 MH.

Any ideas please

 

Den

[Tracker]

To find out the correct PCD in mm (pitch circle diameter) measure between two opposing wheel studs, or if it is easier, between the stud hole centres of a wheel.

The handbook may well tell you what yours is, 4 being 4 stud and 5 being 5 stud.

[Robinhood]

One is for the 16" wheels fitted to the "light" chassis (with hubs initially designed for the previously standard 15" wheels), and the other is for the "heavy" (maxi) chassis with hubs always designed for the 16" wheel.

 

I think the130 pcd is for the "heavy" chassis, but I'd check before buying.

 

Edited to add - my quick check seems to confirm this.

[Tracker]

Unless you can be certain that the wheel comes from a verifiable source, be aware of 'offset' which is how deep the bolting face is from the internal rim, and just beacuse the right size tyre is fitted does not guarantee the wheel itself being the right size.

It is also worth just checking the wheel's centre bore size is identical.

The rim size should be stamped on the wheel somewhere, usually in inches, eg 15x5.5, check your own and seek out one the same size to avoid any problems with steering or handling - or potential insurance complications if you veer away from originality.

Getting it right is straightforward if a bit complex, getting it wrong is a pain!

[Keithl]

Den,

 

Cut two circles out of paper, one 130 mm diameter and the other 118 mm diameter. Hold them over the centre of the wheel and see which one lines up with the centres of the studs. It should then be fairly obvious which PCD you have. It's not quite as easy as measuring opposing studs when you have five stud wheels!

 

Keith.

[Den]

Brilliant idea. Thank you Keith.

[Tracker]

Two pointed end lengths of narrow wood or metal bolted tightly together make pretty good calipers - and can be used for other jobs too!

[Robinhood]

..if it's built on the "light" chassis with f/r axle weights no greater than 1850/2000 respectively, it will be the 118. (and similar with the Alko lights chassis with those axle weights). The 16" wheels are an option but retain the hubs designed for 15" wheels.

 

..if it's on the "heavy" chassis with f/r axle weights higher than that (prob 2100/2400) then it will have the standard 16" wheels fitted to the 130 hubs.

 

 

[Derek Uzzell]

16" diameter 'factory-fitted' steel wheels for Fiat Ducato, Peugeot Boxer or Citroen Relay/Jumper X290 vehicles (built mid-2014 onwards) have the following specifications

 

Standard ('light') Ducato chassis

– Centre Bore Diameter: 71.1 mm

– PCD: 5x118

– Wheel bolts:: M14 x 1.5

 

Maxi ('heavy') Ducato chassis

– Centre Bore Diameter: 78.1 mm

– PCD: 5x130

– Wheel bolts: M16 x 1.5

 

Both wheels have the same rim specification - 6Jx16 ET68.

 

("ET" stands for einpresstiefe (German for "insertion depth" or "offset") and is the measurement in millimetres of how far the wheel’s centre line is from its mounting face.)

 

So - instead of using the PCD for identification - just measure the diameter of the wheel's centre bore (ie, the round hole in the centre of the wheel) that will be either 71.1mm (standard/light chassis) or 78.1mm (Maxi/heavy chassis).

 

A 15" diameter steel wheel will only be suitable for a Ducato standard/light chassis, as it won't fit over the larger front brakes of a Maxi/heavy chassis. The two variants of the 16" diameter are significantly unlike (different centre bore diameter, PCD and wheel-bolt dimensions for each variant): consequently they are not interchangeable.

 

Where the above data become really important is when 'aftermarket' alloy wheels are to be retrofitted to a vehicle that has steel wheels, or where larger diameter and/or wider alloy wheels are to be fitted to replace original alloy wheels. Even if the replacement wheels have the appropriate centre bore, PCD and wheel bolt/nut dimensions, if the ET and/or rim width are ignored there's the potential for the replacement wheel to contact suspension/brake components or the vehicle's bodywork.

 

This 2016 forum thread related to incorrect alloy wheels having been fitted to a motorhome.

 

https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/PJB-Baccs/45547/

 

 

[Den]

Thank you for the posts, I’ll remove the hub caps and do a little measuring

Den

[colin]

As your 143 is on the heavy chassis it should be the larger size, if you find it has the smaller size wheels you need to investigate why.

[Derek Uzzell]

As Colin has said, any Ducato X290-based motorhome built on a 'heavy' (Maxi) chassis will have wheels with a 5 x 130 PCD.

 

(Rather than try to remove the centre cap from a wheel still in situ on the motorhome, it might well be easier just to remove a wheel-bolt and measure it's diameter - 16mm for a wheel with a 5 x 130 PCD)

[John52]

Derek Uzzell - 2022-04-03 12:37 PM

 

As Colin has said, any Ducato X290-based motorhome built on a 'heavy' (Maxi) chassis will have wheels with a 5 x 130 PCD.

 

(Rather than try to remove the centre cap from a wheel still in situ on the motorhome, it might well be easier just to remove a wheel-bolt and measure it's diameter - 16mm for a wheel with a 5 x 130 PCD)

 

My heavy chassis wheelbolts require a 21mm socket

Maybe someone with the light chassis could check what size socket their wheelbolts have?

[Derek Uzzell]

If only it were that simple...

 

The M14 x 1.5 wheel-bolt used for X250/X290 'light' chassis with factory-fitted wheels and the M16 x 1.5 wheel-bolt used for X250/X290 'heavy' chassis with factory-fitted wheels BOTH require a 21mm socket-spanner.

 

https://www.autodoc.co.uk/febi-bilstein/1888426

 

https://www.autodoc.co.uk/febi-bilstein/1888427

 

Regarding wheel-bolt tightening torque settings

 

For the M14 x 1.5 wheel-bolts use 160Nm/118 ft-lb

 

For the M16 x 1.5 wheel-bolts use 180Nm/133 ft-lb

[John52]

Derek Uzzell - 2022-04-03 8:36 PM

BOTH require a 21mm socket-spanner.

 

I didn't know that - but I suppose it makes sense. So they all get the same wheelbrace, jack & spare wheel carrier winder - which are turned by the wheelbrace.

[Dduallt]

The head on the end of the wire of the spare wheel carrier are different, because of the different PCDs.

[Derek Uzzell]

That true, though Den has a Carthago A-class model and that's most unlikely to have the 'windlass type' under-chassis spare wheel carrier that's usually found on Ducato panel vans (and on a few profile coachbuilt motorhomes).

 

(I assume Den will carry the spare wheel in his Carthago's rear garage and (if that's so) the wheel will need to be safely secured.)

[Tracker]

Derek Uzzell - 2022-04-04 1:08 PM

(I assume Den will carry the spare wheel in his Carthago's rear garage and (if that's so) the wheel will need to be safely secured.)

 

Maybe easier to secure if it is laid flat on the floor, with jack and wheelbrace alongside, or in the wheel well if they will fit?

[John52]

Dduallt - 2022-04-04 11:53 AM

 

The head on the end of the wire of the spare wheel carrier are different, because of the different PCDs.

 

Yes - I discovered that when I took mine back to the main dealer for a recall (new carrier) and discovered they had fitted the wrong one. - 15" instead of 16". It was such a bad fit I had to take it back again for them to get the right carrier - 4 trips in all. By the time I had finished I wished I had never started - because I always secured the spare wheel with a fencing bolt through the floor anyway to stop it getting nicked.

- but the spare wheel carrier winders are all the same. So keeping the same size tops on the different size wheelbolts means they can all have the same wheelbrace, same jack, and same spare wheel winder,

[Den]

When I finally decide to purchase a wheel, I have a bracket I manufactured some years ago to suit the tie down rails and luckily this MH has the same as the previous MH.

[colin]

If I remember tonight I'll get some sort of 'easy' measurement for you to differentiate between the two, as 'we' have a light and heavy van parked together.

[Den]

Thank you Colin.

That would be very kind of you and I have to say kind of everyone with their ideas.

Den

[Derek Uzzell]

There are several online PCD calculators that work on the the distance between two adjacent wheel studs or holes and the number of studs or holes (5 holes in the case of a Ducato X250/X290).

 

This is an example

 

https://www.westerntowing.co.uk/pcd-calculation/

 

I don't know if one can take the hole-to-hole measurement with the Ducato wheel still on the vehicle, but it's 99% certain that Den's Carthago motorhome's wheels have the 5 x 130 PCD and M16 x 1.5 wheels bolts used on Maxi/'heavy' Ducato models and (as I said above) to be 100% sure, take a wheel-bolt out and measure its diameter.

[colin]

Well I looked to see what was the easiest way to measure a distance on the wheels to quickly find if they where 130 PCD or 118 PCD, anyone technical look away because you'll hate this. :D

With steel tape measure to hand, hook the end over one bolt, measure to bolt furthest away, either of the two bolts will do. For 130 PCD it will be around 122 to 125mm, for 118 PCD it will be around 115 to 118mm, bare in mind I did this in less than ideal conditions so might be a mm to two out.

 

[Derek Uzzell]

This webpage provides simple guidance

 

https://tyremen.co.uk/article/fiat-ducato-motorhome-wheel-fitment/

 

If using an online PCD calculator, the critical measurement is between the centres of two ADJACENT wheel-studs or wheel-holes.

 

Using a pocket calculator, for the 5-hole wheels used on a Ducato X250/X290, having measured the distance between the centres of two ADJACENT holes, dividing that measured distance by 0.5878 will give the PCD. (For 4-hole/stud wheels divide by 0.7071 and for 6-hole/stud wheels divide by 0.5)