I know, these are as rare as hen’s teeth!
It’s been a real struggle to find a Stevenson Jack XK type A with bolted lifting arm, 1/2" hex drive.
Is there anyone on the forum that might have any idea where one of these might be hidden and possibly available.
I have posted on the JL Classified without result.
Good luck - they are certainly not easy to find, but persevere, they are around.
I have recently (January and March) sold TWO of these I had spare to my needs.
This photo may help.
I may have an extra jack that looks similar to the one pictured here. I’m not sure if there are significant variations, are there distinguishing features or dimensions I should check when I pull the jack out of the parts bin? My parts bin is aimed at late Mark V cars but occasionally an XK part gets under the tent and mixes with the stock (and the Mark V has many shared parts with XKs)
The correct Jack for an early XK120 (1949 > c Oct 1950) is as pictured, and is Jaguar Part No C.2953, albeit this C.2953 is retained for all the later variants of this Jack as used on XKs up to 1960 that all have a welded-on square-tube lifting arm (and other differences)
But yes, late Mark V also used this same identical C.2953 Jack as per the pictured one, indeed I have no way at all of knowing whether pictured Jack is originally ex-XK120 or ex-late Mark V.
Earlier Mark V Jacks, part number C.2654 vary in a number of areas, and are NOT correct for any XK120.
The characteristics to look for, is the overall-length of the main tube.
The swaging-arrangement (indented groove) at the top-end of the tube.
The Hexagon-Size of the Driving-Nut at top of Jack.
The lettering on the top of the cast foot, and indeed often there is a mm/yy date stamped underneath.
The very-characteristic CLAMP on the tube, to hold the lifting arm - and its adjustable position on the tube.
And most importantly the correct ‘H’ section lifting arm, its length, and the angle of both ends - that allow for the angle the arm sits at, with a couple degrees movement only possible on its pivot-bolt.
But if you do have a correct late Mark V Jack, all the above detail will be correct.
If you have a similar STEVENSON or SMITHS STEVENSON Jack as supplied to other than Jaguar (all manner of other British cars received STEVENSON Jacks), then all the above characteristics will determine exactly what make/model of car it was supplied to, bearing in mind STEVENSON Jacks were first introduced in 1936 (thus evolving manufacturing characteristics), but offered in a variety of lengths, and a variety of Lifting Arm arrangements
I have one meeting the exact specifications in Roger’s post. It is perfectly functional and I am presently using it as the jack in my newly restored 1959 XK150S FHC. It is date stamped 1/49 on the base. I acquired it while I owned XK120 Alloy 670005 which had been constructed in June 1949. It is now surplus to my needs.
That’s good news Tom,
Any chance of a photo of both Jack and one of under-the-foot showing 1/49 date.
Roger
Tom, Roger and Roger,
It’s been great that my post generated so much enthusiasm to find the period correct Jack. There were two correct Jacks available, one from a UK dealer and another from a dealer in the US, both for what I considered very high prices.
Roger McWilliams, seeing my post took a look in his garage and found a jack marked under the base 9/49 and fitting the description of the jack Roget Payne described. He made it available at a very reasonable price and I now gratefully have that part of my search sorted out.
Thanks for all of the input and consideration.
Hi Tom,
I have a June 1950 made 120. Do you still have the jack? Pics?
Thanks,
Dennis
Per one of their recent email flyers and though you’d pay $$$, Welsh Enterprises may still have two of these:
Thanks so much for your reply. I saw this one, but the black foot threw me as being a true early 120 type.
Yes, the clamp is correct, but the black square bar side arm is Mark IV, the hex drive is too big (Mark IV), the swaged top end of the post and the black dimpled foot are later, mid to late '50s I believe.
So, I am not such a stickler for perfection. What I have laying around are two incorrect jacks from some other LBC (maybe Sunbeam Alpine). The square stub-out on these jacks is the wrong size and angle for a XK120. I’m going cut that stub-out off and weld a new, larger, stub-out to the shaft. I do not expect this to be passable as a concours correct original, I’m purely going for functionality. My question is, what is the length of the XK120 stub-out, and how far from the bottom of the shaft should it be? For reference, this jack is 19" long from the bottom of the foot to the top of the tube.
Mike,
As ever, Roger has the answer. See the pdf in his post. XK jack: same as any other make or model? - #2 by Roger_Payne
I would also like to convert a non-Jaguar SJS jack, but so far have not found a source for 30mm x 3mm square tube in US. Are you folding your own tube?
Regards,
Clive.
Not sure where to start here - as there is two competing agendas.
Those who want a Jack that will reasonably work functionally and dimensionally for any XK120 regardless of its exact 1949-54 age, thus opens up the opportunity of finding/obtaining a non-Jaguar SJS (style) of Jack, and modifying it to suit…, or…
Those who want the correct/original Jack for their particular age XK120, given that these are ALL Jaguar Part No C.2953, but came in five major detail/cosmetic variants over the XK120 1949 to 1954 period that I identify as C.2953/a, C.2953/b, C.2953/c, C.2953/d and C.2953/e noting that variant /e extends into XK140 use up until Dec 1956 with further variants /f, /g and /h used by XK150 until superseded by the revised functionality C.16392/a and /b Jacks used up until the last XK150. These C.2953 Jacks are unique to Jaguar XK only, apart from the C.2953/a, /b and /c variant Jacks were also used for Sept 1949 to July 1951 Mark V saloons, superseding the C.2654 Jack as used for earlier Mark V Saloons.
So its complicated if you want the exact correct Jack for your XK120…
Simplistically for any XK120 the following is there approximate date range…
C.2953/a and /b. (both, bolted arm type) For XK120s 1949 to cOct 1950
C.2953/c. (welded square tube type) For XK120s cOct 1950 onwards
C.2953/d For XK120s late 1952 onwards
C.2953/e For XK120s Jan 1954 onwards, and all XK140 to Dec 1956…
The /a and /b Jacks are particularly complex, as during 1949 the original STEVENSON Jacks (Made by Britool) were taken over/slightly modified by SMITHs INDUSTRIES who now branded these Jacks as SMITHS STEVENSON .
Its to complex to go into here, so if anyone has SPECIFIC questions, I will try and respond.
Similarly if anyone wants to pursue the alternative of modifying a non -Jaguar Jack to suit an XK120, I can advise the critical detail that makes for a reasonably suitable functioning Jack, that can be easier or harder, depending on the exact donor Jack used…
HI Roger,
Ref early XK120 Jacks, I am ordering your April 2008 article for XK Gazette, but pending that, which jack is correct for the early steel bodied 120’s…one with “Smith Jacking Systems” imprinted on the top of foot, or one with Stevenson Smith Jacking Systems" on the foot. Many thanks,
What you see in the photo is a piece of 1-1/4" x 1-1/4" square tube that is ever so slightly too large. I’ll either shrink it by scoring the center of the length of all 4 sides with a hammer and chisel, or take 1/32" off each side with a grinder.
Some more, but needs some relevant background…
For simplicity - lets refer this distinctive style of XK Jack a STEVENSON Telescopic Jack. These STEVENSON Jacks were first introduced in about 1935/6 and were indeed first used/purchased by William Lyons for use in his new 1936MY SS Jaguar, and were continued to be used in all 1936-40MY SS Jaguar (including SS100) then postwar in the Mark IV and Mark V saloons, and also in all XK120, XK140 and XK150 up until 1960. So 1936 to 1960, excluding of course the close down of production during WW2, there was 24 years of Jaguar usage of these STEVENSON telescopic Jacks, but as expected a considerable amount of evolution/change in detail over these 24 years.
The initial STEVENSON Jacks were actually made by Jenks Brothers Limited, but given the concept was covered by a number of STEVENSON Patents, all the pre-war Jacks, and post-war Mark IV era to early 1949 Jacks are unbranded, apart from having cast on top of the round foot … STEVENSON JACKING SYSTEM / WORLD PATENTS. In 1949 Jenks Bros. sold up their rights to these STEVENSON telescopic Jacks to Smiths Jacking Systems Ltd, with 1949 being a transitional year of outgoing Jenks made Jacks and incoming Smiths made Jacks being used/deployed by Jaguar by Jaguar for three different overlapping models - the Mark V Saloon, the Mark V DHC and later on the new model XK120. So 1949 was a really complicated /messy year for Jacks, but still no branding as such, but three or four variations in the cast in lettering found on top of the foot but not 100% aligned with being Jenks or Smiths made…, albeit if Smiths made, then SMITHS would feature now in the cast in lettering, but in at least three different wording combinations. After the messy 1949 transitional year, Smiths made Jacks now settled down to a consistent design and lettering, still initially no branding, but the cast in lettering on the round foot was now SMITHS / STEVENSON JACKING SYSTEMSmith. Now this is I am sure based on legal advice, as although these Jacks were now made by Smiths, and indeed incorporated a new Smith’s patented design aspect, they still incorporated Stevenson’s patented design detail, but with some complications, these Jacks remained consistent over full XK140 period until January 1957, when things got somewhat complicated again, with Smiths selling out to new manufacturer B.T.C., being relatively short lived, then selling out to Prima Industries Limited in mid-1958 who continued to make these similar design telescopic Jacks up until their last supply to 1960 XK150. The BTC and Prima made Jacks do not have a cast foot, thus no lettering cast on top, but instead had a pressed steel cup shaped round foot with 3x 3 pressed in dimples.
So the 1957 to 1960 XK150 period is complicated/messy. The 1949 Mark V/ XK120 period is messy, but the 1950 to Dec 1956 XK120 and XK140 period is, with complications, relatively straight forward.
Thats a quick overview 
Part 2…
These STEVENSON Telescopic Jacks (1936-1960) were covered by Patents around a basic concept of the telescopic Jacking mechanism, which could be customised to suit a large range of different makes and models of cars and trucks…, with three main customising variables…
)Now in SS and Jaguars case - these three customising variations were specified to suit exactly the requirements of SS Jaguar, SS100, Mark IV, Mark V, XK120, XK140 and XK150, and it should be noted, the combination of Jaguars requirements were unique, and not shared by any other make/model of car that also used these STEVENSON telescopic Jacks.
With SS cars and Jaguars cars, Jaguar produced Engineering Drawings that for each combination of these 3 customising variations, they allocated a unique Jaguar Part Number. Jenks, then Smiths, then BTC, then Prima supplied new Jacks to Jaguar, in accordance with Jaguars Engineering Drawings for each unique Part Number. I call these Contract Drawings as they only specify critical dimensions and features - but they are not fully detailed manufacturing drawings, as they merely a means to ensure accuracy to a top level Part Number interchangeability/functional accuracy. In SS Cars and Jaguars case all Jacks supplied over the 1936MY to 1960 period came in only some five different Part Numbers as follows…
Now as above, these five Part Numbers only represent differences in functional/dimensional/interchangeability aspects - including the three customizing variations that are required from the then manufacturer (Jenks, Smiths, BTC, Prima) and does not cover/mention branding, cosmetic, patent feature, manufacturing etc evolving characteristics as they changed over the 1936 to 1960 period.
But of specific interest is the C.2953 Jack as supplied from 1949 to 1959, to late Mark V, all XK120, all XK140 and earlier XK150 to Dec 1959.
Those who just want a Jack that will function/work as per a C.2953, but are looking to modify a similar/but different Stevenson Telescopic Jack as supplied to some other manufacture/model other than Jaguar, are mostly concerned about the three customising variations. Those who want a C2953 that is authentically the same as originally supplied to their particular age 1949 to 1959 XK120/140/earlier 150 need to know also all the relevant branding, cosmetic, and manufacturing variations that evolved over the 1949 to 1959 period of part number C2953 Jacks… AS a heads up, my research and conclusions, identify some eight major variations to the C2953 Jack, that I identify (my system) as VARIANTS C.2953**/a**, C.2953**/b**, C.2953**/c** etc up to C.2953**/h**, noting that during the 1949 to 1954 XK120 period you will find C2953**/a**, /b and /c variant Jacks only.
Next Part 3 - I will detail the three customizing variations that matter to those wanting to modify a non Jaguar Stevenson telescopic Jack into one that functions/works as per an XK120 C2953 Jack, but doesn’t otherwise care about cosmetic/branding/manufacturing authenticity…
PART 3.
For those wanting to modify a non-Jaguar Stevenson telescopic Jack into something that functions/works as per an XK120 C.2953 Jack, the three major considerations are as follows…
LENGTH. As noted earlier, these Stevenson telescopic Jacks were made/offered in four or five standard overall lengths, with this length determining the range of lift available, from fully retracted to fully extended. This is critical for the correctly positioned lifting arm in a cars Jacking point, being able to lift the car to sufficient height for the tyre(s) to be lifted clear of the ground. In Jaguars case the overall length of the Jack is also critical for it to physically fit in its provided stowage location…
For a C.2953 Jack the overall length of the main outer tube is 15-1/4in (+/- 1/4in)
I quote this dimension as this allows accurate comparison, with some minor tolerance for the different manufacturers) for similar Jacks made by Jenks, Smiths, BTC and Prima, that can have a variety of round feet, and a variety if top Drive arrangements and indeed some can have an extended inner tube. In Jaguars Contract Drawing for C2953 they actually specify an overall height of 17in, from the bottom surface of the cast foot to the top surface of the hexagon drive nut. This is most important, as at a rough estimate, of all these Stevenson telescopic Jacks I come across, the majority (3/4) are significantly longer or shorter than 15-1/4in, and maybe only about a quarter are correct length.
It is not feasible to shorten an overlength main telescopic outer and inner tube and internal screw, and impossible or to extend an under length Jack.
The LIFTING ARM. C.2953/a Jacks have an ‘H’ section solid lifting arm, that is bolted into a Clamp, that is clamped onto the outer main tube, with its actual position on the tube adjustable by releasing then resecuring the clamp.
The C.2953/b and C.2953/c Jacks have a hollow square section steel tube welded onto exact correct position on the main outer tube, thus is fixed and not adjustable.
First step is after acquiring a correct 15-1/4in Length outer tube Jack, to simply remove any existing non-Jaguar Lifting Arms. If its an earlier Jack its a simple matter of releasing the cast clamp, and sliding the clamp/arm assembly off the tube. If its a later Jack then its still a reasonably straight forward case of cutting off any welded on lifting arm, and dressing the residual weld to be a smooth/true outer tube. Note, the date of change from clamped on arms to welded on arms varied for Jacks supplied to different makes/models of cars, but usually very early 1950s.
You then need to source a suitably dimensioned square tube and weld it onto the smooth/dressed main tube in its correct position, as per a C.2953. How accurately you do this is based on needing to be functionally correct, or if you are so inclined to be exactly authentically correct.
An original C.2953/b and C.2953/c Lifting arm is made of square tube 1.20" x 1.20" x 0.10" wall thickness, with the outer tube corners having an 1/8in radius. Expect the usual tolerances with these dimensions, with the outer dimensions more 1.195" and the wall thickness +/- .005" . Note, I quote imperial inches as that was how the steel was made/supplied in UK in the 1950s, and not in metric dimensions not used in UK until the 1970s/80s, but in metric its close to a 30mm x 30mm tube (actually 30.5mm) and 2.5 to 3mm wall thickness.
(Depends where you are, and what’s available, but some years ago I was able to acquire a new length of square tube from local steel supplier that measuring now in hand is 1.195 x 1.197 and 0.095 wall thickness, with outer corner radius visually the same as original, but only about enough left to make three more repro lifting arms)
Now the welded on/finished dimensions of the Lifting arm are that the centre line of the 1.20inch tube sits at 4.5in from the lower end of the outer tube to where the centre-line of the lifting arm projects to the mid-side of the main tube. The Lifting Arm is fitted with a deliberate 4-degree drop down to its outer end, with the outer end cut at same 4-degrees so the end is vertical. From the end of the lifting arm, when welded on at a 4-degree angle, the dimension from the end of the arm to the back-side of the main tube is 6.50 inches. When I made a few replica lifting arms I cut my square tube lengths into 6in lengths, then cut one end to 4-degrees. I put 6 in length in a jig to hold at 4 degrees, and then using a half-round file of about 1in radius, proceeded to file top and bottom edges of the tube into a semi-circular shape that allowed the filed tube to sit accurately on the tube at 4-degrees drop down angle, and with a 6.50 inch end of arm length. (It was actually easier to do than it might sound). I then position reproduction cut/shaped arm at 4.5inch centre-line height on the prepared main tube Jack, using an electric welder (as original) did a tack weld top and bottom, then both sides to ensure no movement from correct 4 degree and height position. Then did a full perimeter electric weld around all four sides of square tube, with an original Jack alongside so I could reasonably replicate original weld appearance, given hand welding would have been variable to some degree originally…
The DRIVE. First up, its not a Nut as such, as there is no thread, but given original C.2953 have a Hexagon Drive, they are often called a Drive Nut. Depending on your donor Stevenson Telescopic Jack you may be lucky, as the exact same DRIVE as on a C.2953 is also used by some other makes and model for their Drive.
An original C.2953 DRIVE is a 5/16"BSF Hexagon (0.518-0.525" AF) x 0.640" long with an open-topped round hole (no thread) drilled through, that sits over the 5/16in diameter round shaft extension to the internal main screw. The hexagon drive is secured to the round shaft extension with a solid pin fitted into a hole drilled through the Drive and shaft at 1/2 height of the hexagon. The top of the shaft is visible at the end of the hole, and sits flush or less than flush, depending on assembly idiosyncrasies.
If your donor Jack has a different DRIVE - a hexagon of larger dimensions being common, or a fixed or folding crank arm - they are all affixed using the same solid pin arrangement, so can be removed by drifting out the pin, or at times drilling out the solid pin. This will reveal the same round screw extension as with an original C.2953 Jack, but unfortunately also the hole. If you machine up a 5/16"BSF Hexagon Drive from scratch, best to drill a new hole through drive and shaft, at right angles, to ensure hole lines up to easily fit a new solid pin. If you remove an old larger Hexagon Drive (as I have before), machine the Hexagon down to 5/16" BSF and top down to .640" length (if needed) then you retain the original hole, and can realign with existing hole in shaft, and refit old or new solid pin.
Then all you need to do is refinish/repaint modified Jack as accurately or otherwise as you see fit…
So with the above advice, depending on how accurately you acquire/select a donor Stevenson telescopic Jack, and how accurately you follow my three advised customizing variables, you could end up with a 100% authentic C.2953/b or C.2953/c Jack indistinguishable from a freshly restored/repainted original - or at least something that would at least be a functionally/suitable C.2953 substitute…
See following picture of an original C.2953/c Jack - unrestored, original paint, with dimensions of Lifting Arm and Drive as advised above…
XK120 SPECIFIC.
My last ‘published’ research/conclusions on XK120 Tool Kits, including Jacks - in any detail was in the fully REVISED 3RD EDITION of ORIGINAL JAGUAR XK (by Philip Porter). Other publications subsequently are either relatively simplistic (as required) or not accurate (as I did not have final editorial control - XK120 EXPLORED).
But it should be appreciated, my chapter on Tool Kits in ORIGINAL JAGUAR XK was done back in 2011/12 (Published June 2012), so 12 years ago, and although no significant errors, my research/ refinement has moved on considerably, including I now use a different numbering system allowing continuity and consistency for all my different SS and Jaguar model Tool Kit writings 1936-1940, and 1945 to 1979 (the end of my period of interest). Having said that, back in Sept 2021 I self published a 56 page booklet fully detailing/picturing JAGUAR MARK V TOOL KITS (January 1949 - July 1951) which although as title advises is Mark V specific, the included detail on the TOOLS themselves are as applicable, identical to XK120s of the same age - so correct for all aluminium XK120s, and steel bodied cars to July 1951, with some relevant but not detailed carry on to subsequent July 1951 to Aug 1954 XK120s. I do intend self-publishing a similar detailed booklet on XK120 TOOL KITS (1949-1954) but given other priorities that will not happen in the immediate future, albeit 99% of the research work has been done.
Re XK120 Jacks…
In ORIGINAL JAGUAR XK, I have identified/described that there are three main Jack variations applicable to XK120 (Aluminium, and steel bodied 1950 to 1954), that then I called TYPE A, TYPE B and TYPE C, noting that the TYPE C was also used for all XK140s 1954 to end of Dec 1956, with the next TYPE D Jack being confirmed in one of the very rare January 1957 built XK140s, but otherwise introduced from the first XK150s…
For the XK120 Jacks Type A, Type B and Type C, under my new numbering system I now call these C.2953/a (Type A), C.2953/b (Type B) and now both C.2953/c and C.2953/d (TYPE C). C.2953 being of course the top level Jaguar Part Number (that is only concerned about functionality/ interchangeability) with my added Variant Suffixes /a, /b and /c denoting much more detailed originality/authenticity detail such as branding, manufacturing variations, other visual differences, and indeed paint colour/ finishing detail.
So in my Mark V Tool Kits booklet, in this case re Jacks, I detail the earlier Mark V only C.2654 Jack, the ‘messy’ 1949 parallel (for Mark V) and introduction of the superseding C.2953/a Jack as now relevant to the first 1949 XK120s, and also the next C.2953/b and C.2953/c but also reference the next C.2953/d Jack being introduced from ‘late 1951 onwards’ - so not fully detailed in this Mark V booklet, but of course will be fully detailed in my next XK120 Tool Kits booklet, thus a significant development after my 2012 ORIGINAL JAGUAR XK efforts…
