I am about to reassemble my 3.8L engine when I discovered that the two halves of the seal covers (upper and lower) are different from what is described in all of the manuals I have. According to the manuals, the seal is inserted into a groove in each cover half. Unfortunately, neither of the seal cover halves on my engine have such a groove. The gasket set I purchased has two rope seal halves that probably fit into such a groove, but there is no other seals in the set. One manual mentions that the later engines had a modified rear seal cover, but makes no mention of the seal for an early engine. I am in a bit of a quandary as I can't even begin to reassemble the engine until I solve this problem. I hope someone else has rebuilt an early engine and can provide some direction to me. I guess this is part of the frustration that comes with a engine that has undergone many changes in its history.

 

Ted, the early cover assemblies were gradually superseded with a couple of changes and the one that's available now from SNG is the conversion type to a modern seal, this requires some machining of the crankshaft to fit the seal.

I do have a set of the older style covers that takes the rope seal, you would be welcome to them, they are no longer required as I have upgraded to a modern oil seal.

 

Jon, Will the rope style still fit my block? I suspect it will. Since I just had my crankshaft done, I'd rather not have it machined for the modern seal. What would you like to get for them, in USD? I will be happy to buy them from you if they are what I need.

 

Based on the fact that the older part numbers have been superseded by the newer part numbers, they should definitely fit your block.

If you PM me your address, I will get them in the post, if you can cover the postage, you can have the part happily.

 

Tedone you have an early scroll seal. Your crank has a scroll machined into it. If you attempt to use a later rope seal the scroll will chew it up in a very short time. If your crank is freshly machined you have two choices. Either use the original or have your crank cut at the seal area to accept the rope seal. You must use the proper sizing tool if you go this route. As far as the "modern" seals they are expensive to do, non reversable, and have provided mixed results. The rope seal properly installed is a proper upgrade and the middle road solution. The scroll seal causes few problems except when parking on a hill with the oil hot.--tends to drip as the reverse action has stopped. Best of luck!

 

Ted, George does have a point, you do probably have a scroll seal if your engine is original to the car, I had overlooked that issue, some engines had a a cover plate with no seal fitted on the newer style crankshaft which was the assumption I made.

Just to make sure, can you let us have the engine number, and if you can look at your crankshaft does it have a scroll machined in the crank on the surface directly behind the last crank ?

 

Jon/George,

Yes, my engine does have the older, scroll machined into the crankshaft. I should have realized that there would be no seal based on the fact that there was no place to install a seal in the upper and lower covers and my experience building old Triumph engines. I plan to stay with the original, archaic seal since the engine will likely get only a few miles added once the car is on the road. I appreciate inputs from both of you. Thanks again.

Ted

 

For my education- the original type seal- I assume there is something in there that can be replaced that helps slow the leaking of oil? The only thing I saw on SNG Barratt was the rope seal.

 

Chuck, Based on a conversation I had with George, there is no material used for a seal on the early scroll style crankshaft. The upper and lower covers as well as the scroll are precisely machined so that the oil is moved forward by the scroll as the engine is running. George said the only negative to this seal arrangement is when you park the car on an incline, front facing up. The oil will then leak to the rear and potentially out. I have opted to keep the original seal system since I don't plan to park the car on any inclines once (or if) the car is on the road again. Also, I don't want to take the crankshaft back to the machine shop to have it machined for the later rope style seal.

 

Makes sense- thanks! I haven't heard anything that would want to make me upgrade to a newer type seal. Only sounds like marginal improvements in reducing oil leakage if that. I'll just have to check the tolerances of the parts closely.

 

The scroll seal works like an Archimedes screw, the scroll can get gummed up with deposits, cleaning the grooves in the scroll can get it working again if the leaking has got worse.

Most of the newer type seals are still in 2 halves, if they are not fitted correctly then they too can still leak. I have opted for a different style than the norm which is a one piece modern oil seal, but it seals on outer flywheel mount area, this seal can be changed without removing the crankshaft and is often used on XK race engines.

It was recommended by the guy who did the machine work on my engine, and he has done a lot of XK engines for racing with no problems.

 

I'm in the throes of trying to stop oil leaks on our early '61 3.4.

Took off the sump and was expecting to be able to access the scroll to clean out the threads, but no ! Unlike the earlier XK120 etc. engines, there are no Allen screws in the sump seal groove, so looks as though I have to take out the engine just to remove the scroll cover from behind.

I am right, am I ? There's no work-around, is there ?

 

As a 1961 your car is in the range that saw a change to the rope seal. Without the car or engine number it is not possible to say for sure.

 

See Crankshaft rear seal mystery - Jaguar Mk2 Restoration for some info, you will see in the pics that the Allen bolts that fix the 2 halves together are accessed from the top rather than the sump side, and I can't think of a way to get to them without the gearbox off !

The XK120 had the bolts in the bottom, as did the XK140, but the XK150 had the same arrangement as the MK2 so I am assuming the change over came around 1957.

 

Thanks, for the replies, guys.

George, the KG engine no. says it should have a rope seal (unless someone's modded it) but, as TilleyJon says, it looks as though it has to be an engine out job regardless.

Which is a bit daft, really, as on the XKs you could remove the lower section from below - why did they make it more difficult deliberately ??

So having gone to the trouble of getting the sump off I now have to pull the engine anyway, however at least 90% of the work is already done - borrowing an engine crane on Monday ! Still, I did find that both front subframe mounts were duff, so not entirely a wasted effort.

Anthony