Anyone who has removed or replaced a rear bumper bar on a MK1, MK 2 , Daimler 250, Jaguar 240 and 340 series cars would be well aware of the problems of the 5/16 inch caged nut system used to secure the bumper bar to the mounting brackets. It is nearly a sheer impossibility to carry out this operation without the special caged nut which is a spring loaded boxed nut which sits in a slot in the bumper bar and to which the mounting brackets are bolted.
A club member in the country was in dire straits needing caged nuts to mount three rear bumper bars. He had tried every outlet to get these caged nuts but had been totally unsuccessful. It requires 8 of these nuts to mount a rear bumper
Back in 2001 I did some serious research into local sources and came up with a metric equivalent. It is an 8 mm caged nut and uses an 8X20 mm bolt to hold the bracket to the bumper. These nuts are readily available from Coventry Fasteners at 172 Lavarack Avenue, Eagle Farm [ph 3868 3655] for the grand price of 37 cents each and the 20 mm long by 8mm diameter bolts cost about 20 cents each. The Coventry part number is for the caged nuts is 26 8MCAGEN and the bolts are 26 8X20MZPBN
I contacted Coventry Fasteners and was advised that their computer showed negative stock. I have run across this problem before with this company and asked that they check the actual stock bins, Surprise! Surprise! They had over 100 in stock! A quick 10 minute trip from my workplace at Brisbane airport secured 30 for our country member and I grabbed an extra 10 for myself as every time you touch a rear bumper you can expect to write off some of the caged nuts due to corrosion.
Club members unable to get to a Coventry Fasteners branch can phone [07] 3868 3655 ask for sales, pay by credit card and arrange delivery by whatever method desired such as by post or courier etc.
For many years I drove on drum brakes particularly in MK7s and I did not have any major problems in pulling up. I am of the opinion that a well maintained set of drum brakes is nearly as good as disc brakes however they do have a problem with fade when hot and are darn near useless after being immersed in water while crossing a flooded causeway.
I was happily driving the metallic grey MK 1 which is equipped with drum brakes and knocking up a few Ks when I noticed an appreciable decay in braking effect and the pedal was getting closer to the floor. I almost ignored it as I am getting close to completion of the MK2 disc brake front end which is going to be fitted in the near future. However it is not in my nature to leave a vehicle in a "suspect" state and I also heard a couple of clacks from the front end while pulling up in the shed.
Getting my dearly beloved Honor to actuate the brake pedal while I roamed around outside revealed that there was obviously a fair bit of movement going on in the brake system in the front end. Jacking up the car, removing the front wheels and brake drums revealed brake shoes that were in very good order and brake drums that were smooth and shiny without any scoring. The previous owner had advised me that he had the brakes "done up" only a short time before I acquired the vehicle. When I was preparing it for a "roadworthy" (safety certificate) I had checked the brakes and the shoes and drums were in apparently first class order and they were also checked and passed by the person carrying out the safety certificate inspection.
On close inspection I noted that the automatic adjuster bar was at the limit of its travel. Hold on – what is going on here thought I!. I checked the lining thickness which was the correct ¼ inch and also noted that the trailing shoe on the right hand front brake did not show any sign of contact with the drum. In fact with the brake drums removed you could put your foot on the pedal and get brake pressure even though there was theoretically nothing to push against or to stop the slave cylinder pistons flying out of the slave cylinder.. It turned out that the brake slave cylinders were at the extremity of movement and locked up against the travel limit of the automatic adjuster bar.
The correct internal diameter of a MK 1 Brake drum is 11 1/8 inches. I checked the internal diameter of the drums on this car and found out that one was 11 5/16 inches and the other was very close to 11 3/8 inches. I.e. one was oversize by 3/16 inch and the other was nearly ¼ inch.
The person responsible for turning out these drums to such an amount and refitting them is guilty of criminal negligence. While I have been unable to find out any recommended limits by Jaguar, general automotive industry consensus is that on a drum of this size around 1/8 inch or about 125 thousandths of an inch (.125 inch) oversize would be the limit and after that the drum should be discarded. The problem is that a very hot thin drum under severe braking has the potential to separate the drum brake contact area from the brake drum face assembly leading to a total loss of brakes. What made matters worse is that they had not bothered to consider putting in thicker linings which are readily available by specific order.
I have all sort of good Jaguar things hidden away in the shed at the end of the stables which I have christened "Possum Palace" as a family of possums lives there as well. They have claimed their own paw paw tree which is regularly raided and I can't use the top shelf of the Dexion shelving as they use it for their daytime sleeping site. Anything stowed on the top shelf is promptly kicked off to the detriment of the car parked in the shed! Anyway back on to the brake problem. I found that I had four MK 1 drums which varied from .040 to ,080 inches. oversize and I selected the best two which got a quick hit from the angle grinder cup brush to clean up the light surface rust in the drum contact surface areas followed by a clean up with some 280 grit wet and dry paper.
Resetting the brake shoes and wheel cylinder pistons to the inboard limits of the automatic adjusters and fitting these "new" drums resulted in only a small movement outward in the automatic adjuster bar and the brake pedal returned to a maximum height. The differences in a road test were quite dramatic as I was able to lock up the front wheels on bitumen in a panic stop from 60ks/hr.
My advice to anyone overhauling early model drum brakes [which ceased in Jaguar production in 1959] is to speak to a brake specialist and ensure the drums are properly measured and reasonably legal and that appropriate thickness lining are used to re-line the brake shoes to account for any oversize drums. By the way the correct composition linings for a MK 1 drum brake system are quite soft and the experts at Action Brakes in Nudgee Road, Hendra suggest a maximum life of only 20,000 miles in normal use.
A club member got in touch with me and raised the subject of fitting an electric fan onto a MK2. Some people think they are rather exotic devices however the majority of modern cars use them and particularly anything fitted with an east – west engine except the original Mini is almost guaranteed to be equipped with one. In addition have a look under the bonnet of your modern Commodore, Falcon and Magna and you will find an electric fan doing all of the cooling work.
It appears that one stumbling block for many people is the problem of fitting a sensor to turn the fan on when the engine is starting to overheat. There are several ways of handling this. One is to fit a sensor which plugs directly into the upper radiator hose. I consider this as rather crude and am more inclined to get a new thermostat outlet pipe and have a modern sensor fitted by machining an appropriate hole in the metal.
You might also investigate fitting a genuine Jaguar thermostatic fan switch as fitted to the E types and Series 1, 2&3 XJ among others. These were originally fitted in the cross flow radiator tank. Another access point is the original thermostat switch hole for the starting carbie which is generally redundant as most MK1/2 owners have modified their cars to use a dash mounted switch for the starting carbie function. You would have to do a bit of fettling to make a plate to carry a thermostatic switch
Another method is to fit a manual switch somewhere around the instrument panel. Anyone used to old Jaguars in hot weather will be monitoring the water temperature and it would be a simple thing to turn the fan on when it is starting to get hot. This is done in many competition saloon and sports cars which have had the mechanical fan blades removed. I am told that the only time the fan gets turned on is after the race and when returning slowly to the pits. Note that this switch needs to control a heavy current relay which will do the actual switching. Many modern electric radiator fans could be pulling upwards of about 50 amps while running and you would need an almighty big switch to handle that sort of load.
An electric radiator fan will consume about twice the output of the old Lucas generator. It may be worthwhile to consider fitting a modern alternator to carry the load particularly if you intend to drive the car frequently in traffic. The old Lucas generator has the further disadvantage of being “off line” while idling in traffic while the modern alternator will be on line and supplying power even when idling. I have alternators on two of my historic registered cars [a Mk1 and Mk2] and they are a boon in getting the battery charged quickly and giving better lights in traffic at night
Some of you may have noticed my wanted ad in last month’s issue of the JDCQ magazine. I was chasing a 12 blade MK 2 radiator fan and a club member has responded with a couple of fans available. The story behind that ad is that the early MK1 2.4 cars only had a simple 4 blade fan which is adequate for normal use on the open road and general use but it is absolutely hopeless when caught in heavy city type traffic.
I attended Geoff and Gerry Underhill’s Australia day BBQ at Tingalpa on Sunday 23 January and it was a typical Queensland summer day with the temperature around the 30 degree C mark. I was travelling from Pine Rivers on the Gateway Arterial and sitting on the 100k speed limit with the water temperature gauge steady on 75 degrees. However I got caught in a surprising amount of traffic and a number of red lights around the Capalaba area and by the time I reached the Underhill estate the temperature was around the 100 mark.
Expecting the worst I let the car cool down and borrowed a bucket for water off Geoff [queries he - not another breakdown?] however it had not lost any coolant. The return trip home was uneventful with the temperature gauge sitting as before on 75 degrees.
I have had this problem before in my first MK1 2.4 in 1986 and the fix of putting a late model radiator fan on the car solved most of the traffic overheating woes. I expect it will make a major difference in this case.
While doing all the right things on the MK2 front end I stripped it out completely and had the major components sandblasted. I was contemplating what sort of paint finish I would apply when an acquaintance of mine suggested a paint I had not heard of before. It is Ronstin’s Rapid Dry Industrial Black Enamel. He said he had been using it for years for chassis and sub frame painting and it stood up very well to the abuse and knocks that come with the under vehicle territory.
I purchased some at our local automotive paint outlet in Brendale and was pleasantly surprised at the price that was a tad over $13 per litre. It did require some thinning to spray but covered very well with a really deep black gloss. The quick drying part lived up to its name, as I was able to handle parts within half an hour of painting. As an experiment I really loaded up some areas with paint, which would have produced runs in a standard enamel, but it did not display any propensity to run.
The Blue Mk2 gearbox was very stiff to change. Consultations with Ben Stafford the previous owner revealed that it had always been very stiff. He reminded me that he had actually broken a gear stick in my driveway some years ago and that I actually already owned the gear stick in the car when I bought it from him. I had lent him a replacement we had fitted on the spot so he could get home and had forgotten about it.
Ben suggested it might have bent selector shafts, which I had not heard of before, but he assured me it does happen. He had a few gearboxes in parts that he had acquired over the years. He donated a couple of gearbox top cover plates complete with selector shafts for me to try.
It took a short time one afternoon to remove the centre console, gearbox hump cover plate and remove the top of the gearbox. Note that BSF bolts hold down the top of the moss gearbox and not SAE/NF bolts as I expected. The already cleaned up and prepared replacement gearbox top cover plate was fitted and a trial run was made minus the tunnel cover and centre console.
The difference was immediately apparent and the gear gates could be felt and the gear stick easily manipulated. The “proof of the pudding” was when Ben dropped in one afternoon and I asked him to take the car on a trial drive. He agreed that it was a great improvement over the previous stiff system. I have not had time to dissect the previous selector system to find out what was the actual cause of the problem.
A club member was having trouble with his XK series engine as it refused to fire up after having the carbies overhauled, new points, plug leads etc. put into the system along with a distributor overhaul. The engine refused to run and wouldn't even do the courtesy of giving the occasional backfire or cough. Club member was getting a bit frustrated with the whole thing
Enter yours truly and a few basic points were looked at. Spark plug removed from the front [number 6 cylinder in Jaguars] and a crank over to the compression stroke showed that the distributor rotor arm was pointing at the lead going to number 1 cylinder i.e. all of the leads out of the distributor cap were 180 degrees out. The spark plug leads were reattached in the correct order but still no signs of life when cranked. Careful checking of the float levels in the SU HD8 carbies showed no major discrepancies. There were lashings of sparks as yours truly got inadvertently zapped while holding onto a plug lead and noting that the spark would jump a ½ inch or 12 mm gap. A rough check on the timing showed it to be within the general running range of a few degrees before top dead centre. The fuel strainer bowl was checked for water and it came up clean so basically we had fuel, ignition and compression but still not a running engine.
When all else fails suspect any thing so I pulled the plugs out which were decidedly wet. I can only presume this occurred as petrol evaporated causing water condensation on the plug insulation. After washing them in petrol and drying with an air gun they were reinstalled. A dash of ether start assistance had the engine firing but refusing to idle. Keeping a fairly wide open throttle setting helped keep it running and eventually it stabilised at 1500 RPM, - still not right.
By now it was obvious there had to be a major air leakage in the inlet system as no amount of fiddling with the main jet enrichment system was having much effect on the idle. By sheer luck while suspiciously looking at the engine running from all angles I spotted a joining hose on the starting carbie pipe inlet system that had become disconnected and had left a significant opening for air to bypass the carbies. Apparently the hose had been installed but the hose clip wasn't tight and a backfire in the inlet system had most likely caused it to come off.
Reconnection of this pipe brought some order into the system and after this final mechanical skirmish we had the car idling. There was still a little leak somewhere in the inlet system as the engine was happily idling with both carbie idle air bleeds completely shut off! The best way to chase these leaks is by using a piece of thin hose held to the ear while the other end is moved around the inlet manifold and carbies. However time was running out and I had to leave this up to the owner to pursue.
The grey MK1 2.4 speedo was bouncing a little up to 30 miles per hour but beyond that it really got bad with swings of large variations which meant that at 40 MPH it would flick up to 60 MPH and back again. It looked like a crook speedo cable but as it had a brand new cable I suspected the instrument.
I removed the speedo and on the work bench connected up a drill set to run in reverse with a bit of old speedo cable in the chuck of the drill. I found that the problem was in the instrument as with the drill full on I got 45 MPH with bouncing up to 70 MPH.. I attempted to remove the speedo case and to repair it but was unsuccessful as the trip odometer connection was jammed.
Luckily I have accumulated a number of spare MK1 speedos and I had one which matched the diff ratio for a 2.4. I checked it on the bench and it worked OK but I noticed some serious lag in the indications as it took 5 seconds to catch up to correct speed and a similar time to come back to zero after the drill was stopped. I removed the case and delicately applied with the smallest artists brush a dab of WD 40 on both jewels [pivots] of the speedo needle. That fixed the problem and the replacement speedo was installed and is working as Jaguar advertised.
Sometimes it is the simplest things that get you going (or stopped). One of my MK1s was doing odd things in that the generator and regulator seemed to be all over the place and sometimes not charging. One quiet afternoon I grabbed the digital multimeter and tools and attacked it.
The generator proved quite capable of putting out more than adequate volts and amps. This is a very simple test. Simply attach a piece of wire between the D [dynamo] and F [field] terminals on the generator and start the car. Don't over rev the engine, as 1500 to 2000 RPM should be adequate. Measure the voltage being generated at the generator D terminal. This will be typically in excess of 14 volts and possibly up to 16 or more volts. This is because you have bypassed the regulator. If the ammeter in the car shows a large output that also proves that the cutout is working. It pulls in when the generator volts are typically above 12 to 13.
All this was OK and I now suspected the regulator. I cleaned the regulator points but there was no change and I decided to replace it with a spare that I had. While undoing the terminals on the regulator I found that the screw for the wire running to the generator field was quite loose. Tightening this up was the answer and the generator now performed as Lucas and Jaguar advertised. Moral – look for the simple things first
A club member recently acquired a large British car of the better class [but it was not a Jaguar]. Driving it home some considerable distance, like from Victoria he had an electrical problem in that the Lucas generator stopped working. Parts were hard to get but he soldiered on by buying a spare battery and charger and only driving by day and charging batteries overnight.
The upshot was that there was nothing really wrong with the generator except the brushes were totally worn out and he found that by applying light pressure to the brush springs he could get the generator "on line".
A trip to see Kevin Baker the Lucas guru who lives at Maleny [ph 5494 4221] netted a set of brushes for one of the largest generators you will ever see in a car and the problem is fixed.
However I wonder how many of us are driving around with worn generator brushes. Unscrewing the clamp on the generator cover and simply looking at the top of the brush holder and spring easily inspect them. If the brush is well down in the holder its time to get in touch with Kevin.