ChrisC

Yep. It works well if you don't have a roll bar fitted. The roll bar is in the way otherwise. But if you are single handed and worried the diff may slip off the jack, you can use a ratchet strap on the roll bar to provide security. This will only work with the BMW diff where the cage provides the mount point.

So had very recently first hand experience, my diff has only just been refitted ready for the Fish and Chip run. A couple of things to note, my 2 year old, only 2000 mile (2 track days) diff had NO significant wear. In fact the only wear was the new plate high spots had been taken off, there was no need for any service work to be carried out on the clutches. The reason for my diff removal was to solve a reoccurring noise/vibration problem which had been present from new. This was eventually traced to a bad UJ, so hence the diff was already removed. One recommended is not to separate your wheel bearings from the driveshafts, if you do you will almost certainly end up replacing both. If you are assembled new driveshafts and wheel bearings try using bearing anti fretting paste, but even then there is no guarantee fretting won't occur.

I went for the titanium one from the states, it's exactly the same form as the original BMW design. Time will tell it's worth having (next year when I change the oil again).

Oil plays a part in whine, the historic posts in blatchat proves that. The latest Caterham oil partners diff oil offering maybe isn't the quietest, so I am confident a quieter oil could be found, but what would be the question. There are plenty of posts about Ford diffs and oil choice, not sure about BMW units. Just don't get confused with LSD oil, which isn't needed for an open diff.

An alternative I use is LED fuses, a simple idea but a brilliant one for the seven. If a fuse blows it will light up, that way if your horn isn't working the fuse lit up is your horn fuse.

If I was faced with the same situation, I wouldn't grind the classic bracket, I would enlarge the hole in the replaceable drop bracket, lifting the bobbin, therefore lifting the rad. A guess you would also need to enlarge the bottom bobbin hole. That would be reversible when you get a radiator replacement, with a cheap drop bracket.

From Caterham Parts website, about £742 Radiator, Oil cooler, oil cooler brackets x2 , oil cooler lines x 2, cooling fan, cooling fan brackets x2, bobbins x 4

If you choose this route, don't forget to also factory a smaller cooling fan, mounting brackets for the cooling fan and different length oil lines for the oil cooler.

My only wish would be for CC to not treat road going 420 owners as second class citizens. Race spec 420 owners get the significantly cheaper option to replace just the coolant radiator, but road spec requires oil and coolant radiator to be replaced at the same time. The oil cooler is only held onto the coolant radiator with two bolts.

I have a photo form the factory of a 420 SV, poor quality, I will try and post later. The hose end (connected to the sump) looks a little flat to me, it should be pointing up a bit. Also is your alternator fitted, can't tell from the photos. If not it will dictate that hoses position, especially near the pulley.

My hanger is 25mm wide

My chassis mounting bracket touches the top hose. Only just, but it does touch. I can lift the rad to gain clearance, but it settles touching. I am sure there would be a witness mark on the top hose. Don't forget this top hose had a slimmer side wall to my original so that would have been even tighter (and less flexible)

Sorry I don't, i Ironically at the moment I am also struggling with a problem and have the whole backend of the car disassembled, so have no space in the garage to remove the nose and bonnet. I am killing rear wheel bearings and driveshafts every 1000 miles.

Also the weld on your outlet doesn't look that convincing to me. Sorry this picture is rotated, but your see the weld, and the fact the hose can be fully pushed home and have a hose clamp fitted.

The replacement hose was Caterham parts, just ordered off the website.

I can't understand why your chassis mounting bracket is touching the radiator inlet. I had no issues with that mounting. The original top hose was to inflexible and put a lot of strain on the radiator inlet, thankfully I found that out when I cut it to short, ordered a replacement which was much more flexible and removed strain on the rad.

Hi Mark It is on the site, but you may want to sit down before clicking the link https://caterhamparts.co.uk/radiators/7114-radiator-and-oil-cooler-seven-420-road-model.html?search_query=300C0004A&results=1 Clearance was ok, but only with my second, slightly softer top hose, which was 2mm small in diameter, without that it would have been a problem.

Given this evidence, and assuming you didn't run it up to temp and then let it cool, I would be looking to replace. I think I would also investigate a repair to have a spare. PS mine has a 300C0004A

Mark, not 100% sure it's not spray coming from the hose joint. Mighty be worth cleaning and testing. I know it's clutching at straws but it looks like the hose joint has the most staining.

Have you checked Fuse R, "Keyless Immobiliser" 5A ?

Mine moved back with a simple plastic trim leaver. I removed the wheel and cleaned the rust from the area, then cleaned it again it's rubbing alcohol to promote good adhesion from the Loctite. Applied strong Loctite and pushed it back. I didn't remove the driveshaft from the hub, but I did remove the ARB bracket for better access (if you have one fitted). New driveshaft arrived today, which is about a month since reporting the problem, the delay was mainly due to part lead times.

I understand why the spacers have been added, the bolt supplied bottoms out in the small bobbin, but a shorter bolt is far more appropriate solution. The other problem experienced with S3 installations is the fan (front mounted now) touching the 7 grill, adding spacers would only make this worse. It seems S3 420 are getting new nose cones (as of kits supplied 2021), I am not sure it this is for fit, or increased oil cooler air flow, either way it doesn't address the expansion tank clearance issues experienced by some.

It seems to have started sometime in 2017 (ironically when the new sensor was released). I know of one fellow builder with a 2020 delivered kit that had the issue. So sometime between 2020 and 2021 the fix has been applied by GKN.

Yep, this is a picture of my 420R. It happened at the first proper dry track day, where I assume the driveshaft got hot from the disc. It's a 2020 registered car, but the kit was supplied October 2019. Apparently GKN now apply some form of green substance to secure the trigger wheel to the tripod joint, I wonder what that could be :-). Took as week to confirm the course of action (replacement driveshaft), but I am still waiting for parts. That said I am not in a rush, I pushed the trigger wheel back into position to get a working speedo.

The trigger wheel is known to move on the tripod joint. Caterham replace the driveshaft if this happens under warranty, after all its a part suppliers problem (GKN). If your car is under warranty contact Caterham, if not then consider cleaning the rust, applying some strong Loctite and pushing it back into position. As how I know