I need advice re a replacement oil filter for my XK120. The vehicle was recently restored & fitted with an after-market spin on adaptor and an Asakashi C-409J filter (Outer 102mm, Thread 1-12UNF, Height 135mm). I assume this was attached to the motor before it was lowered into the car. This oil filter is too tall, had terrible trouble removing it at oil change, had to clamp the torsion bar that sits immediately below the filter out of the way and hard against the chassis rail to remove the filter. The engine rebuilder has not responded to request for assistance re brand, part numbers, etc.
I recently bought a Donaldson P502458 (Outer 102mm, Thread 1-12UN, Height 101mm) with the assistance of a filter specialist. Height is great but looks like the thread is the wrong pitch (UN) – I’d never heard of differences in thread pitch so never thought to ask when ordering. I force screwed it on and it seems to have sealed okay but I would like to order the right one for next oil change (thread pitch UNF). Can anyone suggest a suitable spin-on filter to match the following specs please?
Outer 102mm
Thread 1-12UNF (ie not UN)
Height 101mm or close to this.
For those with a spin-on oil filter what filter do you use? It obviously depends on the thread on the post the filter is screwed onto but if you give me the brand & part number you use, I can research the specs.
Cheers,
Hi David,
That sounds like ominous words. Since you are quoting millimeters I presume you are in a metric country and not familiar with the English or SAE thread system. Thread size 1-12 UNF means 1 inch outside diameter and 12 threads per inch, and UNF means Unified National Fine thread series. There is no 1-12 UN without the F thread, so there is some misinformation somewhere.
FWIW there is a 12 pitch thread series used for special designs such as optical instrument threads, but there would be no logical reason to use such a thread on an ordinary thing like an oil filter.
Thanks for replying, Rob. Really appreciate it – there is a dearth of local mechanical expertise when it comes to these cars – must be the age or something
I’m in Canberra, Australia and must confess my total ignorance of the English or SAE thread system. So if I’m reading you correctly, 1-12UN is exactly the same as 1-12UNF? That is, the shorter oil filter I bought Donaldson (P502458, specs on the box: Outer 102mm, Thread 1-12UN, Height 101mm) should replace the Asakashi C409-J (specs on box: Outer 102mm, Thread 1-12UNF, Height 135mm)?
If that is the case, then I suspect the tightness of fit is probably due to some damaged threads from the difficulty removing the original longer Asakashi.
Wix cross references the Donaldson number to their 57106 which is 3.828" tall and 4.234" dia. and has a gasket 3.967" OD and 3.587" ID. It has a bypass relief valve set at 13-19 psi with an anti-drainback valve and 32 micron rating. A short fat one. http://www.wixfilters.com/Lookup/PartDetails.aspx?Part=72544
The principle application is Caterpillar Towmotor fork lifts and loaders.
It looks like the Donaldson is pretty similar. https://shop.donaldson.com/store/cartridges/ProductAttributes-DCI/?_DARGS=/store/cartridges/ProductAttributes-DCI/ProductAttributes-DCI.jsp.1#
Yes, 1-12 UN = 1-12 UNF.
I see both Donaldson and Wix leave off the F, perhaps to save computer space, figuring since they know there’s no difference, they assume everybody else must know there’s no difference?
Asakashi does not come up for a cross reference, so apparently Wix never heard of them.
If your threads are damaged, threading dies are readily available here, and probably somebody in Canberra will have one.
You definitely don’t want to bend your torsion bar at all, ever.
Kind of strange though, as the original filter was quite tall.
You could always get in touch, as I am also in Canberra, and I understand Gavin K. gave you my contact details!
Indeed I am sure I do have a spare original XK120 Oil Cleaner Assembly among my many XK spares, and can put you in touch with a lot of local expertise.
Re threads etc - on your XK120 being a British made car, all the threads/fasteners are a mix of WHITWORTH, that has three variants - BSW (British Standard Whitworth) for coarse threads, BSF (British Standard Fine) for fine threads, and BA (British Association) for extra-fine/small threads, and a mix of UNIFIED threads, that Jaguar progressively introduced superseding the Whitworth threaded fasteners progressively over the XK120 period, albeit not completely. With Unified threads, UNF (Unified National Fine) dominated, with a lesser amount of UNC (Unified National Coarse) but never any extra-fine Unified threads, with all British Industry (including Jaguar and suppliers to Jaguar) preferring to stay with BA.
On this forum, where you get many Americans, they refer to SAE and UN in a different way to British/Australian usage of UNF and UNC, but spanner sizes and threads are interchangeable (with the differences being in tolerances and other minor aspects that don’t affect interchangeability).
And as Rob said - there is no standard 1 inch thread with 12 tpi - certainly not 1"UNF which has 14 tpi, but I do note 1"ANF does have 12 tpi which never had any America SAE or UN equivalent.
(ANF was a short lived British thread used in many XK120 applications, before the progressive adoption of UNF, and is interchangeable with UNF in all sizes except the 1" size with 1"ANF having 12tpi instead of 1"UNF having 14tpi - but there are other physical differences that do not affect interchangeability)
But don’t feel bad, most Americans (regardless of age) and most younger Australians still have trouble understanding BSW, BSF and BA spanners and threads, let alone the 1" ANF versus 1" UNF anomaly.
Thanks Roger,
If you have time would really appreciate if you could send your contact details to dmckay5@internode.on.net. I’m floundering, last two filter changes have been ridiculous, and reading of the potential pitfalls has me worried – wrong bypass valves/seized engines etc. The concept of a spin-on filter seemed good. I may be able to get away with restoring the thread on the adaptor but also not afraid of the reported mess of changing an original element.
Thanks Bob, maybe the tallness of the original isn’t a problem as the housing is released by undoing and raising that big top bolt shown in your photo, rather than unscrewing a contemporary filter which needs to come down the full length of the central thread before being released.
Kind regards,
David McKay
1"-14 tpi is the odd one. I forget where we found that one, was it on the Salisbury axle shaft ends? My Machinery’s Handbook had all that stuff but I can’t find it, hope I didn’t leave it at the office when I retired.
For completeness, here is the UNC thread schedule.
Everybody download those two and keep them for reference.
As we said, UNF or the earlier version ANF is found on the XK engine, chassis suspension components, and driveshaft u-joint bolts. UNC or the earlier ANC is found on threaded holes tapped into aluminum castings such as the XK head.
So when you want to know about SAE threads (1906) or USS threads (1870s) or Sellers threads (1864), ask an American.
You are 100% right Rob, and maybe your comment ‘old friend’ is the clue - my memory is failing
I should have checked…
The new UNF standard indeed introduced 1" size UNF having 12 tpi, which in UK superseded the temporary ANF series of 1"ANF having 14 tpi, and indeed in USA, the old 1" SAE also having 14tpi.
This in the XK world is important as the rear-axle shafts on a Salisbury rear-axle, indeed uses 1"ANF - 14 tpi threads, which can be a challenge if you need replacement 1" ANF slotted-nuts.
