Installing a new Rear Crankshaft Seal to Minimise Oil Leaks in your Rolls-Royce or Bentley

"Hi there and welcome back. So today, we are going to talk about crankshaft modifications and the seal on the back of the engine.

Originally, when the V8 was introduced with the S2 the seal on the back of the engine was a scroll type seal. So that means that in the back plate (this is a modified back plate) there was a thread on the inside and that was close on the flange of the crankshaft, which meant when the crankshaft starts spinning and the oil is getting thrown out it's hitting the thread and getting thrown back in the engine. That's the basic way it works but correct me if there's anything else to be said on that.

What that meant is that there was no physical seal and if your engine ever was very high or you park on a slope, oil will just leak out of the back and they are prone to oil leaks. So in 1978 / 1979 with the Shadow II B series engine, not the first Shadows II models, but the late Shadows II B series, they modified the crankcase to take a back plate with a seal in it, a rubber seal or a lip seal. Now that meant that a lot less oil was lost, but it does also mean that you can now modify the earlier type engines to take this type of seal. What you need to do is take the gearbox out. Take the ring gear off, which will expose the back of the crank here. The back plate is fitted onto the back of the crankcase like this. Two bolts underneath that hold the sump on and a ring of bolts around here. That will come off, bolts pressed on with the dowels, then you expose the back of the crank.

Now we've taken the extension piece off this one and I think some are fitted with an extension piece and some are not. We have taken it off to show you how the seal is fitted, but the new seal will fit straight over this flinger which is part of the set up on the early type of seal. If there are any issues with this.. if this is bent or damaged or it touches the new back plate than what you can do is you can actually remove this part, this outer ring and replace it with this sleeve, which is the correct size for the seal. These seals are a bit fiddly to fit, because when they're in the back plate and you are putting them on, if you haven't taken the sump off then you'll have taken the back plate off with the sump. You will have to cut away a bit of the sump gasket and try getting it all in this together, the ideal way is to remove the sump and fit a new sump gasket when this is in place, but if you're trying to do it with the sump in place, you might just want to undo the sump around and drop it a bit, but you have got to slide this seal over the back of the crank and that can be quite fiddly to get it all in line together.

The advantage of these seals we have got in now is that they come with this applicator. Basically it is flared at the back. So you fit that on the seal here and then you squeeze it down, so that the flare on the applicator just opens up and seals slightly just to get it over and then the idea is that you can just slide it on like that. That's now on easily and it should aid the fitment. If there are any questions, then feel free to ask and we've got the seals available. They will go straight in the B series onwards back plate or if you wanted to carry out the modification then you need the complete Back Plate Assembly. We've got back plates with the seals in stock, so whatever you want to do with it, we are kitted out for it!"

The full Crankcase Resealing Kit (UE41408KIT) includes the following parts:

• UE41408 Rear mains Cover, Seal and Applicator
• RH10046 Sump Gasket Kit
• UE5214 Rear Mains Cover Gasket
• RH12774 Breather Pipe Gasket
• UE5726 Dowels (x2)
• WHT002844 Setscrews (x7)
• UA1251ZP Washers (x7)