Great work, Bob and Terry! I’ll try to go and see mine early tomorrow before it gets too hot. Well, 36°C is pretty hot for England!
Chris
Bob,
From S811693… a Sept 1955 dom XK140MC
Stamped: C5721 3-C-55 44 and C5721 7-C-53 29. (Long-end to Shackle at rear)
Roger
Chris,
Curious for the outcome of the rear spring history. My sympathies regarding your endeavor in the heat! Today will be 37C (100F) here in Holland to be continued for a whole week. Holland was known for its cool and wet weather, competing with the UK in that respect. We lost both due to climate change, I’m afraid
Roger,
Thanks for your input. It seems like one of your springs has been replaced by an earlier 1953 version from exactly the same batch as the one on Tadek’s car!
See the updated table. It’s remarkable what we collectively can do on this Forum! In just 3 days we have a pretty good insight in the date codes of these rear springs.
Bob K.
I suspect a normal stock holding issue with both springs being as fitted by factory from new. Both springs, gaitors, lacing, shackles, bushes, washers, bolts and nuts were identical. No sign anywhere that they were anything other than the original factory fitting. So I to was initially surprised to see different year stamped in but now see it as just another example that Jaguar only controlled stock at a part number level and not overly concerned about stock management in wharehouse
Roger,
That might well be possible Roger but still 2 years is a (very) long time.
Found the page below in a 1935 William E. Cary brochure in which various spring types are shown including one coded C3. I guess “C” might stand for Cantilever and might also be the origine of the C in the first code. We haven’t found any figures over 10 (so far) in the first code, which might indicate (again no proof) that this is a month code. The second code goes up to 53 presently, so we should not excluded that this is a week code but could also be another production code.
Bob K.
Well, here are the pics of my spring stampings. I bought them as just “XK120 or XK140” springs, so quite expected to see they were C3661, but found that they are C5721. I suppose the slight additional stiffness will be a bonus, plus (hopefully!) less of a propensity to break. The numbers are: 9 C 62 33 and 3 C 63 12. BTW, I think the number on the first picture I posted some days ago is 33, not 35, as you listed it.
Thanks Chris,
I will include the new one in the table and make the correction for the other.
BTW C.5721 was used on XK 120’s from December 1952 onwards. Don’t know what year your car is but the C.5721 is therefore quite standard for these XK 120’s. So these springs are typically replacement springs for the (later) XK 120’s and 140’s with their respective year codes 62 and 63.
Is this the same spring as offered presently on eBay UK? If it’s not you (“sylvigeorgio”), than we found an exactly identical code 9-C-62 33.
Bob K.
Hi Bob,
my car is Dec 1950, so would have had the C3661 springs originally. Aftermarket ones are on it at the moment. So the C5721 is an acceptable repalcement. I expect Jaguar themselves stopped supplying the earlier springs after they were superseded anyway. No, that spring on Ebay is not mine - quite a coincidence that the numbers match one of mine! The picture I posted 4 days ago was of that Ebay spring.
Chris