Colin Heseltine

Tim - Gulf Seven, Interesting to see your breakout torque dropped by 4ft.lb when swapping diff oil. I changed to the Redline LSD oil an mine dropped 4ft.lbs from 43 to 39ft.lbs. 420R just over 2 1/2 years old with 16500 miles on clock. Colin

I was after the RRT diff oil but as you say due to shipping difficulties they are not prepared to send it out. I asked them for a recommendation and they said to use Redline 75W90 GL-5 LSD oil. I used this and noticed that the preload dropped by around 4 ft. lbs to 38.5 FT lbs. This is on diff in 2021 420R which has done almost 16200 miles in last two and half years. Colin

I changed my diff oil two weeks ago and used the standard USA quart container from redline. This is 0.98 litre. Drained around 0.78 litre of old oil. Just been under car after doing over 1700 miles last weeks and no sign of leaks from the oils seals. Colin

Jonathon, No problem. I though it best to try the horses mouth even though the answer was not the one I really wanted. Hope saves someone else from searching needlessly. Colin

As there appears to be some confusion on this issue I decided to drop an email to Simon Lambert at Caterham. I had an initial response from Lee Bristow as follows: Your model will have an additional 12v twin connector located at the rear of the car. If this connector is not visible along the section of wiring loom running down from either side of the differential, then it has likely been secured in the area under the tunnel blacking plate in front of the differential. I investigated further but did not wish to start drilling rivets out without being 100% certain. I had a number for Lee and spoke to him and he went into factory to investigate. He got sidetracked but then emailed my back with updated response: I must apologise for the confusion, as it transpires that the UK spec Duratec loom does not have the additional 12v socket connector, unlike the EU spec Duratec. So no 12V socket on UK Duratec. I did pose the question as to when a 12v socket is fitted to the car why is it put where no-one can get to it. Because very few people use it was the response. If you cannot get to it easily you wont use it I said. He did agree with me and said it did not make any sense. So whilst I had the transmission tunnel cover fully off the car and the boot floor out I have put in my own cable. Colin

I have lowered floors and lift the car on a quicklift hydraulic lift. I have made some 19mm marine ply rubber coated boards with cutouts for seat bolts and crotch harness bolts. These sit on top of quicklift (rubber side to floor) and spread the load over the majority of the area of the lowered floor. At least 2 square foot each side. Works well and is solid, no movement. Colin

Chris Zooming in into your picture there is a rubber sleeve over something. Could that be it? Mine looks a lot like yours rather than the previous picture. I have had the camera up there a few times now, can see brake pipe, main cable run and washer pipe, but not actually above them. Problem is it would mean drilling all the rivets out. I guess the fuel pump feed is the only other always live cable (when ignition on). Colin

David, Did you draw that cable in yourself or was it in the manual. The manual I have seen does not show it marked on the similar schematic. K7VCT. How do you define boot to cockpit area. Thx

Managed to remove the transmission cover without removing seats, no cable under the cover. Did not remove the ally panel. Will have another look with camerascope from underneath. Now looked with camerascope and cannot see a cable tied to chassis rail. Is there anything else at rear of car which has a permanent feed I could piggyback onto, i onl;y need a few miliamps.

Jonathon, Thank you. I had seen that post and used that as initial guide. I do not think it is in boot. The boot is carpeted and had I seen a stray connector at that time it would have been labelled and left available. I do not really want to remove the transmission cover unless someone says yes it is under there. I have tillets and these would need removing first. Looking for a particular colour cable is a no go due to colour blindness. Regards, Colin

I am looking for the mythical 12v rear permanent power feed on my 2021 420R. Has anyone ever found this cable and if so where did they find it. Do you have a photo of where you found it? I have spent some time underneath the car with torch but can see no sign of a spare connector. I have seen comments about looking for cable tied up in transmission tunnel but cannot see one. Or is it underneath the faux leather transmission cover (I hope not). Would have tried the google site search but for some reason this does not appear to be working today. Colin

I would not attempt to connect into the loom behind the dash. I ran two extra cables through the bulkhead. The existing cables are very thin diameter and there is not a lot of length to work with. I certainly could not have got arms and head under the dash to see what I was doing. I did not want to run the cables with the main loom up the centre of the transmission tunnel above the bell housing. For present I have fitted a bulkhead gland (on passenger side of the bulkhead) and run the cables through that. Also have the cables for the 12v DIN plug and USB socket/voltmeter running through same fitting. At a later point I may fit a proper bulkhead connector which can be unplugged. Could put some pictures up tomorrow possibly but currently car is in garage under its cover. Colin

Steve, I was talking to Stuart Cresswell about the intercooler/heat exchanger a couple of days ago.

I was out in my 420R up in the Peaks this morning. Cars and fields white over with frost in many places and puddles at side of road frozen, and slush across the road in odd places. My oil cooler is blanked off completely and I never saw the needle go out of the blue section of the temp gauge. I have a switch to switch between water and oil temp both showing on standard water temp gauge. I ran separate cables rather than mess with the cable loom. The cables in the loom are quite thin with very little spare length. The oil temp sender is in the tapped outlet at the bottom of the DS tank. The water temp is happily at the usual 95 degrees. I have the carbon dash and did not want to drill it. I made a small aluminium bracket with a 90 degree bend in it. The bracket is tyrapped to the large connector plug in middle of the dash. This way the switch is out of sight, is reasonably firmly held and I can just reach it when belted into the tillets. I do wonder at this time of year whether to put an insulating coat around the DS tank. The only time I have removed the cooler blanking plate is when I did a track day. Colin

With my Tillets and the lowered floor in my 420R SV I found could not get the seat to go fully forward, especially when I needed space behind the seat to adjust the crotch straps. Push the seat back as far as can get it and then put a wooden block about 25mm thick underneath the adjustment arm to force it up in the air. Then push down firmly on the bar and bend it downwards, pull up to remove the wooden block and should now be able to move seat forward and the arm will slide below the crossmember. Just be careful of your fingers when move set forwards. Colin

To make it easy to refit the tillet seat I use the following trick. Find three bolts about 40mm long with the same thread as the nut in the base of the runner. Cut the head of the bolt. Screw the cut off bolts into three of the nuts on the base of the seat. Lower the seat into place, the three bolts can easily be aligned with the holes in the floor. When the three bolts are through the holes the fourth hole will be lined up niceley so you can thread the bolt in from underneath. Remove the cut off bolts one at a time and replace with correct bolt. One thing you will find is that without the spacer bars small stones makea horrible noise whgen you move the seat. Colin

I fitted a DIN socket for connecting my CTEK charger and also fitted one of the combined USB-A, USB-C and miniature ammeters. These both fitted on the front of the panel which covers the fuse box area. Also have the original Cigar lighted socket still in place.. The cigar lighter is switched by the master key and the combined unit and the DIN are direct to the battery. The combined unit also has a smll on-off push button. GIves me the best of all worlds. Can have sat nav and phone plugged in and other half can charge her phone/ipad at same time or even charge battery packs. Colin

I drilled the bulkhead on my 420R and used a standard bulkhead gland. Fitted it with the nut on the inside and the cable gland nut which compresses the rubber seal on the engine side of the bulkhead. Had no leaks so far. I am running the leads to the CTEK charger and the leaders from oil temp and water temp sender through it as well. Colin

Just done over 2000 miles spirited driving in last 2 weeks round Scotland. Preload down to 43.5ft lbs from 44ft lbs (manual torque wrench). Electronic torque wrench shows around 1ft.lb drop. Car now up to 10700 miles in 18 months from new. At the moment radiator is bigger issue than the diff. Colin

A great trip which I extended to 2056 miles by the time I had been back up to the Moray Firth. Colin

To be honest, no. To my mind, Oakmere, The dealer, should be checking these things. The car is a factory built one, still within warranty period. The first radiator only leaked by the top hose connection. This one appears to have leaks in several places. Colin

I had a new radiator fitted in my 420R SV car in November last year, the car had done 5715 miles and car was about 8 months old, so still under warranty. The new one started to weep a couple of months ago. Just done a 2056 mile trip round Scotland which included a return journey of 480 miles in 11 hours. Over the two weeks I added around 3 litres of coolant and I cannot pinpoint an exact location for the leak but there appear to be a number of them. So this radiator has lasted just under 4500 miles. I am talking to Oakmere about getting another fitted asap. The car has 10700 miles from new in 18 months. Am I going to need another in 5000 miles time or thereabouts, just as the car has gone out of warranty. After the next one goes belly up do I bite the bullet and get a Radtec, or get Caterham to keep supplying new rads as the problem has not been sorted. Radtec are only a couple of miles from me. The last radiator I had of them lasted for 30,000 miles on my 1600 K series engine. Colin

Geoff, I was planning to get the oil changed. The car will be due its 12000 mile service before the end of the year at which point I will still have 3 months left on the two year warranty. I asked Oakmere about the Caterham recommendation re oil changes. I know someone one here showed the Titan recommendations, but I'm sure someone posted the Caterham recommendation but I cannot find it. If someone can indicate which post has their recommendation I will chase it up with Oakmere. I have got the magnetic sump plug fitted. There appear to be several schools of thought re the oil, Motul 75W/140 or the GLS 90. I assume the car has the Motul in it at present. Is it going to pay to continue with the same oil. I changed from my 24 year old 1600K to get away from having to do jobs on the car. At 73 next time round my back, knees and shoulders are getting past wraunching heavy bits from underneath cars. Colin

Just done another pre-load check on my Titan diff in my 17 month old 420R. The car has now done over 8600 miles and will do another 2200 in the next 5 to 6 weeks. Car has done one afternoon track day at Donington the rest has been road mileage Both wheels turn in the same direction and pre-load was 46ft lbs using a Clarke digital torque adaptor, this was checked 4 or 5 times. Next used a good quality 3/8 drive wrench where I could bring up the torque on a pound by pound basis. This was locked at 44 ft. lbs but moved when set to 45 ft. lbs. Again this was done several times. So far so good, fingers crossed. I will check it as soon as get back from trip. Colin

I have a 420R which was new end of March last year. Currently done around 8050 miles, so approx 500 miles month since then. Checked pre-load last week prior to a Donington trackday (first one for the car). Pre-load was just over 43ft. lbs. The car still has the remainder of its 2 year warranty. Within the next 2 months a further 3000 miles will be on the clock. I guess by the time my two years warranty will be about to finish the car will have around 13000 to 14000 mile on the clock. If Caterham are suggesting a rebuild at 10,000 miles should I ask them to do it FOC, because I don't see why I should pay for something like that within the warranty period. Colin