1975 Jaguar XJS V12 Manual #27

Help solve the mystery…

One of our cars is a very early manual Jaguar XJS Pre HE and we are trying to solve the mystery of how this car came to be. If you have any information on the history of this car, or have any observations please contact us.

Data:

• Car 2W1027BW
• Body 5W1029
• Engine 8S1033SA
• Gearbox (number on chassis plate & heritage certificate) 28054
• Gearbox (number on hat) KFN12007 - KFN is an XJ overdrive geabox
• Gearbox casting date 13F2 - 13th day, F=June, 2=1972

Car is listed on XJS Data website link here.

Built 11/2/75, 7 months before the XJS release on 11/9/75.

Delivered to Hollingdrake, Liverpool 4/9/75, 7 days before XJS release and one of the first batch of cars sent to distributors (noted on heritage certificate).

There is an 18 year gap in the history of the car from 4/9/75 to 1993. If you have any information on this car during this period, please contact us.

Car registered in NSW Australia as ADS18Q in 1993.

A private owner (name withheld for privacy reasons) from Tamworth NSW Australia bought the car around 2000 in NSW. This owner suggested the car was the Melbourne motor show car or some sort of press/demonstration vehicle.

Car sold to Jagdaim Melbourne, Australia in 2003.

Car sold to a Melbourne boat builder (name withheld for privacy reasons) by Jagdaim in 2003. The car had some cosmetic modifications during this period, all original parts were retained.

Car featured in Jaguar magazine issue 117 ‘XJS Conception & Misconception’ read a copy of the article here.

Car bought by LGM in 2018, the car had been off the road for a period of time.

Car recommissioned 10/20 with RWC and historic registration. Works completed by Mike Roddy.

Gearbox and engine rebuild completed 8/24 by Jagdaim.

Research:

L1076 Radiator Tag:

Jaguar radiator expert confirms L1076 tag decodes as follows:

• L = Leeds, England where the radiator was made by Marstons
• 10 = October
• 76 = 1976

18 months after the car was built it got a new factory V12 manual specification radiator (no oil cooler). This proves the car was a manual at this stage (late 1976). There were no other V12 manual Jaguars in production at this time which precludes it from being a second hand part installed later in the cars life.

JB Inscription on clutch input shaft:

After taking the gearbox out and inspecting there was no evidence of it being taken apart before. We discovered a JB inscription on the clutch input shaft which appears to have been there since the gearbox was built.

A Senior Jaguar Development Engineer from the XJS Experimental department noted ‘JB’ was the junior member of the 2 man team who were in charge of all transmission development in Jaguar Experimental (names withheld for privacy reasons). “For fuel economy or performance testing cars had to be manual, so many were converted in Experimental. When ex test cars were sold, they were usually sold to preferred customers who might specify the car in manual transmission specification and as a favour this would be carried out. This car may have been built for a Jaguar Department not related to Experimental. It’s not on any Experimental fleet list, but there were odd cars in Experimental that were on no lists. It may have been built for the Service Department or an important supplier or customer. The gearbox would have been built up from ‘bits’ around the factory. The ‘JB’ on the input shaft was for internal use only and not expected to last inside a hot gearbox!” The gearbox being made up from ‘bits’ would be why the number on the hat references an XJ overdrive gearbox.

1st gear ratios in the gearboxes of early XJS and E-Type are slightly different. XJS KM manual gearboxes have a 1st gear ratio of 3.238. E-Type KL manual gearboxes were 2.933. This made the XJS have a 10% lower first gear making it pull away with more revs. Although the casting date on the gearbox is 6/72 #27 has XJS ratios and not E-Type which indicates the gearbox was made from ‘bits’.

The manual conversion was done after the car got its data plate in roduction as the number on the chassis plate and heritage certificate do not match what is in the car. Further the car was originally slated to be an automatic hence the BW suffix in the car number.

The gearbox is correct factory V12 manual with 2 pins right hand side for the slave cylinder (6 cylinder cars are on the bell housing). All other parts related to the manual are factory correct, pedals, gear stick, gear knob, boot etc.

Overdrive was being tested as an option between 1972 and 1975 (XJS #27s gearbox is date coded 6/72) by Jaguar Engineering. They experimented with a 2 speed rear axle, it had a large overdrive unit fitted to the front of the final drive unit designated Salisbury M20, this required a modification to the differential area. After inspecting the differential area, there is no modification which means this car was not a development car for the M20 overdrive but the date code on the gearbox falls into that development period.

The speedometer and odometer are both in kilometres, not miles as per a domestic UK car and the tachometer is machined in the same manner.

Les Hughes editor Jaguar Magazine and winner of the Sir William Lyons International Jaguar Award for journalism re. #27. “I had a car from Experimental with looms for V12 and six, and fittings which showed it had both manual and auto boxes. There was a small ring at Jaguar at that exact time made of blokes from that department who were selling off the cars they were supposed to take to the crusher. They got caught, all were sacked and one killed himself. There were some big names amongst them too.”

Car 2W1130 was a press car and is the first ‘official’ manual V12 XJS. Built 21/8/75, 6 months after #27 and dispatched 22/9/75 17 days after #27.

Summary research:

• The car was a manual in late 1976
• The gearbox is correct factory V12 manual
• The gearbox has early XJS V12 gear ratios however the casting date is 6/72, an overdrive option was being developed between 72-75
• JB on the input shaft for the clutch: ‘JB’ was the junior member in charge of all transmission development in Jaguar Experimental
• The radiator is factory correct V12 manual and date coded 10/76
• It was not uncommon to make parts up from ‘bits’ in Experimental
• The pedal box and all associated fittings are correct factory manual
• Jaguar magazine issue 117 notes the car may have been a development vehicle
• Previous owners dating back to the 1990s were told the car was some sort of Australian press or demonstration vehicle
• Car was built 7 months before it was dispatched
• Cars were built in Experimental for different departments, important customers or suppliers
• The speedometer and odometer are both in kilometres and machined the same way as the tachometer

Questions to be answered:

• When did #27 have its manual gearbox installed and by who?
• When did #27 come to Australia?

Can you answer any of these questions? please contact us.

Possible scenarios:

Option 1 - Works completed before the car was dispatched:

The car went from Production to Experimental sometime during the 7 months after it was built and before it was dispatched. The car was converted to full manual specification, the ‘JB’ initials could suggest the gearbox is from that department. This would have been done for either performance testing as cars needed to be manual, built for a Jaguar department not related to Experimental, a development car, an important supplier, customer or a dealer demonstrator.

The car was sent to the distributor 7 days before release and a few weeks before the first ‘official’ manuals were dispatched. When ex test cars were sold, they were usually sold to preferred customers who might specify the car in manual transmission specification. The car went to Holingdrake Liverpool with the first batch of cars as noted on the heritage certificate.

The car for some reason in late 1976 needed a new radiator as the radiator is tagged 10/76. Because the car was already a manual, it got a new manual specification radiator (no oil cooler).

If this is the case, how and when did the car come to Australia?

Option 2 - Australia:

As per above however the car was built for a special customer from Australia and dispatched to Hollingdrake for delivery (a practice not uncommon). There is a suggestion the car was some sort of a press/demonstration vehicle. The car could have had the full manual conversion completed before it was dispatched as cars were built for special customers in Experimental.

Or is it possible that the full manual conversion kit was dispatched to Australia and the works completed here by Jaguar Rover Australia?

Was #27 an Australian manual press/demonstration vehicle? The speedometer and tachometer could point to this. A previous owner believes there were 4 early cars that came over together #2 (McCormack race car), #12 (Press car), #27 and #53 (Australian launch car). The Australian XJS launch was in 6/76 at the Jaguar National Rally in Mildura 9 months after the European launch and 4 months before the date code on #27s radiator. #915 was the first ‘official’ Australian XJS on 21/5/76. Looking at the underside of the car there is no evidence of the car spending much time in the UK on salted roads and in damp conditions. Structurally the car presents as a dry climate car. There is no evidence that supports this claim, however this has been suggested by previous owners.

Option 3 - Works completed after the car was dispatched:

The car was converted to full manual specification in late 1976 as the radiator tag is October 76, this could have happened in Australia or in the UK. The geabox could have been supplied through Experimental and made up from ‘bits’. This could have been installed at the dealer or the car could have been sent back to the factory. Was the car a demonstrator and sent back to the factory to be converted to full manual specification for demonstration purposes? Unlikely as factory manuals had been on sale for 12 months by this point. Did the first owner commission the conversion? Also unlikely as there would be no reason to go as far as to change the radiator when the standard blanked off automatic unit would suffice.

Do you have any information on this car or any observations that can help solve the mystery? please contact us.

What they have said about #27:

Jaguar Magazine issue 117: “#27 is almost purely phallic! It seems to have unlimited torque, and an unlimited ability to accelerate. The gearbox gives you much more driving fun, while the note sounds like a turbine as you are gently, but forcefully, pushed deeper into the upholstery and utter ‘Yesssssss…’”

Mike Roddy: “Gee that goes well! That is awesome, not too many XJS drive like that, I don’t know too many XJS that could keep up with it. Wow, after that I need to get my head out of the clouds! I was told by a fellow who worked at Jaguar that all of those early cars were fitted with special camshafts”

Below Watch: XJS #27 in action...