My 140 was pushing out oil through the front seal and gasket after a decent drive. I changed them but the leaking continued. A 70yr old mechanic friend had the car for a few bits of job and called me to say that the vent hole was covered in black paint.
”What vent hole”, I said…
It is located on top of the right tube, about 5” outside the diff unit. Visible by mirror and light, and can be felt with fingers.
So he cleared the hole, and that solved my leak in the front end of the diff.
Just to safeguard: he drove it for 20 min and can´t see any traces of oil after 24 hrs. I seem to remember that it took several days before I had oil on the floor, but let+s hope that he found and solved the problem.
Perhapsvthis is common knowledge to all of us…Do the late 120 and 150 cars have this small vent holes as well?
My 240 axle had the same hole 1968 , and a earlier LSD had the same , I thought it was poor , so added one from a Land Rover , nice brass job with a one way valve
For those few of us with the ENV differential, the breather appears located in the same area but with the addition of a shield to prevent dirt ingress. Thanks for this timely post as I’m noticing my differential covered in grease/ dirt radiating away from the driveshaft seal area. Need to check for breather blockage after a good cleaning. And I’m envious of those few with older garages that sometimes had an inspection pit underneath. Too bad they’re no longer code compliant.
Code compliant, luckily for me, doesn’t apply to private premises in the UK. my new garage, built 18 months ago, has a long inspection pit on one side of the workshop. LED lighting, several power points, ladders at both ends and a jacking beam on rollers makes it perfect!
I don’t expect you to change it, but I would respectfully note that it is very hazardous to install electrical outlets in a pit that will be exposed to hydrocarbon fumes. Hydrocarbons are heavier than air, so they will collect in the lowest confined space available. In an industrial environment, a pit like this would at a minimum be electrically classified as Class 1, Division 2 and could easily be rated a Class 1 Division 1 hazard. It doesn’t take much evaporating liquid to make a large vapor cloud.
And I’ll give you a fix for the hazard. Ventilation is recognized as a valid mitigation for explosive or combustible fumes. 1 cfm per square foot is generally considered adequate to provide enough dilution air that the fumes cannot reach combustible levels. Engine bays, the bilge, on boats have the same hazard. You can use 12 volt marine bilge blowers, which are rated for hazardous environments, to evacuate any hydrocarbon fumes from the pit. Extend a duct from the suction side of the blower to within 3 or 4 inches from the bottom of your pit. Before you enter the pit, turn on the bilge blower for 2 or 3 minutes before entering. Owners of boats with inboard engines will recognize the routine.
I’ve had this kind of pit since 1982 - this is the third garage I’ve built with one. The ‘traffic’ over the pit is so low as to be almost non-existent, as I drive over it and switch off, there’s never a vehicle running over the pit with the covers up. There’s one of the cars always parked over it, with the covers down. I’ll work on a car over it maybe 3-4 times a year, depending on the project. Nothing with the engine running except to get over the pit.
I restore cars - nothing ever moves anywhere under its own power!
The cars that run live in the main garage next door, no pit, separated by a wall.
I’m happy for your good fortune with pits, but that does not mean the hazard does not exist. It is indeed very real, and it does not require a running vehicle. All it needs is a fuel leak, a stuck float. You are free to do as you please, but there is a good reason why a pit would not pass a building code or electrical inspection. Others should know the hazards before they emulate your choice. Keeping flammable things from going BOOM! and leaving a smoldering crater was my profession.
Mike. The addition of a bilge blower is a good idea but If I am not mistaken you should not be placing the suction side of the blower into the pit. They are designed to blow fresh air INTO potentially contaminate enclosures to evacuate the contents which eliminates the possibility of drawing volatile gas through the blower.
The explosion hazard is not the pit, per se. The hazard arises from the installation and use of common NEMA 5 electrical devices in a subgrade confined space in an area where Class 1 flammable liquids are stored, dispensed or used. They make no mention of the electrical design, but presumably the lighting conforms to the requirements for Electrically Classified areas.
Why would anyone go through installing one of those when you could buy a 4 post lift that is enormously safer, no doubt for less money? A pit is a huge liability.
I think you mean a dust cap. Surely the air has to go in and out as the temperature changes.
I hope you didn’t leave it orange. Black is correct on all diffs. The orange was only important on the inside to seal in microscopic remnants of sand from the casting process at the foundry.
I plan on digging a pit very soon , my garage is only about 10ft tall , no room for a 4 post lift , I can dig a hole and shutter the sides for less then £500 , how much is a 4 post lift ?
Can always have a hose pipe to hand , for a fire , and a cage on the ground for gas
Well, planning restrictions on height, complexity and cost, but above all the fact that in a home workshop a four post lift means one side of your workshop is pretty much useless unless you want to lift a car up. For most of the time, my pit is covered over and just another area of floor workspace. I’ve tried working in shops with both 4 and 2 posters, and there’s always a flippin’ post in the way! The twos take up less space, but then you get the car up in the air, wheels off - just need to release a steering lock to turn the front axles, so I’ll open the driver’s door - DOH!
With the pit, I get the car over the pit and I’ll have the brake fluid all changed in 5-10mins, no need to remove the wheels.
