Rear oil seal oil leak

[Tony]

It looks like I have developed the dreaded rear oil seal leak which has gone from an annoying drip to a full scale leak.
I am not in the mood to be pulling out the engine and replacing with another rope seal that will probable leak again after 13k miles.
Can anybody recommend a garage to do it and how much will I expect to pay.
Has anybody ever found a permenent solution to this problem?. I know their are loads of topic on this but I feel a problem shared it a problem shared.

[Heuer]

I went through this and took the car to CMC. They did not recommend fitting the modern lip seal because it is too much of a gamble. Basically the crank needs to be permanently machine altered, the lip seal cut in half and super-glued back together when in place. It is only with the engine back in the car and running you know it has worked as it fails immediately and catastrophically. The only option is to remove the engine and repeat the process hoping it goes right. CMC say the rope seal works well providing it is properly prepared (allowed to steep in oil for a week) and installed (with the correct sizing tool and skill) and indeed mine has been perfect for the last 20k miles of hard driving. Incidentally my seal failed, according to CMC, because the crankcase breather was not big enough and the increased pressure blew the seal. My car had an ITG filter so was venting to the road rather than via the vacuum assisted plenum connection. They replaced it with their double exit breather both venting to the road.

Cost of fitting the rope seal is buttons but there will be 12 hours labour to remove/refit the engine and whilst it is out you may as well have the bottom end checked for wear which may mean new big end bushes and a crank regrind. You won't have much change out of ?1,500 I guess. You really do need to take it to someone who will guarantee their work though - CMC, E Type UK, Paul Brown Classic Jaguar in Ripley, Ken Verity in Rotherham are a few to consider.

[christopher storey]

Tony : first ensure that it is the rope seal . There are a variety of leaks which mimic this , most particularly from the cam feeds and also sometimes from the bolt threads which go through into the camshaft oil gallery and hold the half moon blanking plates on

Also , on your particular car, even if it is the rear seal I should check that it has not been overfilled again, remembering the bent dipstick episode and the fact that you recently lent it out !

PS I could not agree more with David about modern lip seals. It is irreversible, and of the 4 with which I am acquainted, 3 have been catastrophic failures requiring new crankshafts because of course, once machined to accommodate the new seal, the metal on the tail of the crank cannot be put back !

[Tony]

David ,

I hope the bearings are ok as the engine was totally rebuilt by VSE only 13k ago. I did notice my son had checked the oil level And did not put the stick back in properly so it could have come out of there.
I will report back when I clean all the oil off.

[Moeregaard]

All of the above plus the sump gasket and rear seal. Oil can come out of here in a big way, so try bringing up the torque slightly on the sump bolts, before taking anything apart.

[Tony]

I will check the sump gasket as it does leak a little bit along the side. Any thought on the torque I should take it up to?

[christopher storey]

Best to do it by hand feel using a short open ender because from memory they are only 5/16 UNF or even 1/4 i.e. 1/2 AF or 7/16 AF. If you are going to use a torque wrench , I would do it progressively and not go much beyond 10ft-lbs in the case of 1/4, and 15 ft-lbs for 5/16

[Tony]

Thanks everybody, I will start next week. Chris you must call in ,but do not worry it will not be to do work.

[johnney]

I went through this and took the car to CMC. They did not recommend fitting the modern lip seal because it is too much of a gamble. Basically the crank needs to be permanently machine altered, the lip seal cut in half and super-glued back together when in place. It is only with the engine back in the car and running you know it has worked as it fails immediately and catastrophically.

That's true of one type of rear seal conversion, but the preferred conversion involves machining off the flywheel mounting flange and the scroll on the rear of the crank, then using a modified seal housing with a modern one piece lip seal. This also involves drilling and tapping holes in the rear of the crank to take a modified flywheel. All this is normally done on an exchange basis.

[Durango2k]

Hi,

does anyone have a picture how it looks like ?

I will have to find someone locally to do this for me, so a pic would help.

I think it may be a nice idea to use a ready- made hollow sleeve on top of the machined area ?

We had this subject somewhere a few days ago... IIRC it was Wuerth in germany delivering polished hardened sleeves....

Carsten

[johnney]

This is Rob Beere's version, scroll down to crankshafts and you will see a picture of the seal installed.

http://www.rob-beere-racing.co.uk/engine6.html#6lip

[38E]

One way to confirm whether or not the problem is a leaking rear seal is to look at the front side of the flywheel.

If you don't have a pattern of oil marks radiating out from the centre, it's not the seal, so it's something else. As already said, there are many other culprits that appear to indicate a bad seal.

There's nothing wrong with the stock rope seal. The only problem is incompetent installation. I installed my own when I rebuilt my engine maybe 16-17 years ago and it still does not leak.

[christopher storey]

That's true of one type of rear seal conversion, but the preferred conversion involves machining off the flywheel mounting flange and the scroll on the rear of the crank, then using a modified seal housing with a modern one piece lip seal. This also involves drilling and tapping holes in the rear of the crank to take a modified flywheel. All this is normally done on an exchange basis.

Preferred by whom ? And why does the flywheel need any modification ?

[johnney]

Preferred by whom ?

preferred by anyone who has the good sense to realise that a two part lip seal glued together with super glue is never going to be as reliable and therefore preferable to a one piece seal. a two part seal is just a cheaper way of doing it.

And why does the flywheel need any modification ?

For the following reason,

"but the preferred conversion involves machining off the flywheel mounting flange and the scroll on the rear of the crank"

If you machine off the flywheel mounting flange, what will you mount the new flywheel to ? The new flywheel has mounting holes with a smaller PCD to match the new flywheel mounting holes that are drilled and tapped into the end of the crank after machining off the flange and scroll.

[christopher storey]

Ah ! I suppose the one piece seal will not go over the original flange diameter. Even more reason to avoid this appalling piece of butchery !

[JEP41]

For what its worth!

I modified my crank to accept the lip seal conversation and superglued the new lip seal together before mounting into the modified housing. Todate the car has covered 12000 miles over the last 10 years and completed half a dozen track days. The seal is showing no signs of leakage or failure.
We use super glue on a regular basis when assembling seals in Gas Turbines and have encountered no failures over the years, preparation is the key.

[johnney]

O rings are a suitable candidate for gluing and are available in a kit which includes a selection of lengths and diameters of rubber, razor blade, cutting guide and super glue. These kits have been around for years, I have one myself but they are only recommended for static seals. Is this the type of seal your refer to using in turbines? You can buy two piece CV joint gaiters that avoid the need to strip down the drive shaft on FWD cars that require gluing of course but they are just a time saving measure and no matter how good the preparation can never equal the integrity of a one piece item. Yes as David alluded to earlier, you can be lucky and they might last a number of years but not necessarily a high number of miles. Most lip seals have a spring to maintain lip pressure on the shaft, this would have to be stretched to get it over the flywheel mounting flange unless it also has a joint. As Clive pointed out earlier the rope seal is fine if its fitted correctly. As you say preparation is the key, plus skill and knowledge! Personally I prefer to stick with the rope seal.

[JEP41]

You are right Johnny the lip seal has a spring but it is not stretched to clear the flywheel flange it is the hooked type. Just unhook, fit around the crankshaft and rehook. Re usage most of us with David as the exception possibly, do not do excessive mileage in these cars and 12k over a ten year period is not unusual. I have two other classics plus my Ducati which all share in the annual mileage I do. To date I have three XK engines two 3.8 and one 3.4 all running with the modified lip seal conversion and touch wood all appear to be working fine.

[Tony]

Well my rear oil seal was not as bad as I thought. My son had checked the oil level and not put the stick back in properly, so most of the oil came from there. I still have a weep around that area and one around the distributer
area. I have tightened up the sump gasket but I am left with a weep around the rear gasket seal and some where at the front end.
I cannot see much further without removing parts etc so will live with it until I have to do some work around those areas. It just annoying

[frogeater]

Hello Tony,
What a good news!
You must find something (?) for your child because it can't last forever like that: an electrical and a oil problem, that's too much!