Diff numbers, what do they mean

(Morris Barnett) #1

Just did a diff rebuild on my 150,and found these numbers stamped on the diff case, can anyone identify the significance.
F - could this be the body number 150 OTS body number starts with F
58 - could this be the year, my car is a 1958 model
2185 - could this be the manufacture production figure.?

(Rob Reilly) #2

F58 could be June 1958.
2185 was the score of the Manchester/Birmingham match.
The orange paint means “orange ye gonna pay me whatchee owe me fer the match?”

Ok seriously the 2185 is probably the serial number counting from June 1.
I have one stamped C53 559 probably dating from March 1953 and one stamped A0 1786E which I could believe means January 1950.
Please paint it black.

(Morris Barnett) #3

You one funny guy, luv it.
Car was built July 10 so June 1958 sound logical.
As requested . Black.

(Lee140FHC) #4

Hope you cleared out the vent and grease-escape holes…

(Paul Wigton) #5


(Morris Barnett) #6

Lee I know about the grease vents but where is the axle vent ???

(Nick 53 XK120 OTS) #7

still tryin to find out what diff I have on 120,it is a 3,54, I have done the revs test, On the left lower flange facing rear is cast raised US PAT 2018188, and above that on the left upper flange US PAT 1968618 (or similar…hard toread), and on the right lower flange facing rear, is a very small circled A, under it small “44”. And above that on the upper flange is cast 18418. it is a 10 bolt rear cover with the rear cover extended part for internal gear clearance about 3 in wide, the iron fill plug faces rearward on the right side of the bolt on cover.,iron drain plug on bottom, it has a very clear raised “69” on a smooth flat on the top of left side (visible only from above), On the underside of nose is stamped B53 135. No other marks or cast / Leys

foundry marks, No “C part#, and it is likely not on its original axle tubes , no marks at all on either axle tube. It is an “open”…jacked up one wheel turns…other does not. I know it is a 3.54…verified by wheel/drive revs. It is likely from 1960s…mayby 70s…has to be prior to 1983. It is NOT with original axles assembly…so no axle tube numbers.

(Lee140FHC) #8

Really testing my memory here but I seem to remember the small vent hole(maybe only 1/8") is close to and inboard of the brake union mounting bracket, at or near the top surface of the axle tube. Other axle makers use a much larger vent with a suitable cap to prevent ingress…or even a tube running up to a “protected” spot up under the body shell.
Just took a look at my axle assembly…the vent hole on mine is to the right side of pumpkin, just about UNDER the brake line clamp as it sits on your axle. However, my 140 axle has a welded-on brake union bracket on EACH side of pumpkin, presumably to accommodate both LHD(my car) and RHD. Could be they changed locations of vent holes, but I doubt it.

(Rob Reilly) #9

Thar she blows.

About 1/8" diameter (3mm). Only on one side. Presumably placed so it doesn’t get covered by splashed up road dirt and oil from inside won’t come out.

(Paul Wigton) #10

PROOF positive Jaguar designed in factory leak spots…:slight_smile:

(Mike Spoelker) #11

You can blame this one on the Yankee origins of the Salisbury axles. The original Salisbury gear works, where the design originated, was in the USA.

(Morris Barnett) #12

I am assuming the photo is an ENV diff otherwise the hole would be on the bottom for a Salisbury, I shall look on the top in this location later today and report.

(Morris Barnett) #13

Nick The only info I can give is what Rob Reilly told me re the B53, = B manufactured in February ,53 the year of manufacture, the 135 probably items produced in that month maybe.

(Mike Spoelker) #14

The axle tube vent holes in two different 4HA axles, one from a XK120 and the other from a XK150. The vents are in about the same location on both. The drill bit is 3/32".

(Rob Reilly) #15

No, its a Salisbury and the hole is on the top. It does not leak. The oil on the axle shaft at that location does not whirl fast enough to get thrown up and out.
IRS diffs have a kind of stove pipe vent on the rear cover.

(Mike Spoelker) #16

I have never seen one on an axle of XK origin in a location other than the top of the right side axle tube.

(Lee140FHC) #17

Didn’t surprise me to see a mount on either side of axle since I presumed the brake line would run to the rear based on which side the pedal was on…my LHD has brake line running along the left side of chassis. I have not seen other axle housings, aside from the 2HA I have “in the pile”.

(Terry McGrath) #18

this might help date stamps and serial numbers all the diffs in XK140’s sent to Australia

Year Chassis Axle type Number Ratio Speedo
1955 800040 (S/DN) F54 5247 46-13 (3.54)
1955 800059 (-/-) F55 6981 46-13 (3.54)
1955 800065 (-/DN) K55 2249 45-11 (4.09)
1955 800066 (S/DN) A56 8702 46-13 (3.54)
1955 804031 S/DN L54 288 45-11 (4.09)
1955 804164 (-/-) F54 5250 46-13 (3.54)
1955 804259 (-/-) C55 6283 46-13 (3.54)
1955 804271 (-/DN) F55 1235 45-11 (4.09)
1955 804326 (S/-) E55 10 43-13 (3.31)
1955 804327 (-/-) F55 6711 46-13 (3.54)
1955 804328 (-/DN) F55 965 45-11 (4.09)
1956 804465 (-/-) K55 7835 46-13 (3.54)
1956 804719 (-/-) D56 G324 46-13 (3.54)
1956 804751 F56 9545 46-13 (3.54)
1956 804790 (-DN) L55 2621 45-11 (4.09)
1956 804808 (-/-) B56 8943 46-13 (3.54)
1956 804815 (-/DN) L55 2566 45-11 (4.09)

1955 807034 (-/-) A55 817 46-13 (3/54)
1955 807070 (S/-) B55 1044 46-13 (3.54)
1956 807301 (S/-) K55 2363 46-13 (3.54)

(Nick 53 XK120 OTS) #19

interestin, as the car is a roll off the factory, March 19, 1953.,.but this diff has the odd US Pat numbers, and the circled A 44,and no Leys.,.so curious. Is it ori to car,.,maybe the Leys ran out and this came from elsewhere?, is it a total replacement from unknown source, the US Pat, #, if it was replaced,this is a US shipped car, so would have been done in US, Searchin the web I have not found a match, NickUploading: diff circled A 44.JPG…

(Morris Barnett) #20

Lee ,Terry ,Rob
Thank you all for the valuable blow hole information, after a time consuming effort I located the little rascal hiding under the handbrake clamp, completely blocked with crud and my lovely red oxide primer and black paint which I ruined in the process of locating, but no worries I can sleep tonight knowing my rear end wont explode.!!!