Fitting the Crankshaft rear rope seal

[44DHR]

I am helping out on a couple of winter projects, one on a 3.8 XK150 and the other on a 4.2 Series II E type.

We are working on the re-building the 3.8 engine first and then will tackle the 4.2 engine. We are presently starting the re-assemble the 3.8 engine and assessing the fitting of the rear crankshaft rope seal. Some articles mention soaking the seal in oil overnight before installation, but others appear to show the seal being worked into position "dry". Our supplied seals are white in colour and "dry", but am I confusing dark coloured seals in some articles as perhaps a different form of supply - such as pre-impregnated with an additive such as graphite ?

I understand the requirement to tap the seal on the sides to narrow the section and then slowly roll it into the groove using a round bar, but I am confused as at what point is it then soaked overnight in oil. Is it then removed after pepping and trimming to be soaked as I would be concerned that any fitment would be changed once it was oil soaked ? What is the purposes of the holes at each end of the seal sections ? Do pins need to be inserted into these holes ?

One interesting web article by "Vintage Vehicles" shows a photo at the end of the installation process once the two halves are clamped around the crank where seal shows an imprint of crank spiral groove to confirm full contact all around the journal. I then read another article which states that when using the Jaguar sizing tool, (JD-17) that there should be a 1 to 2 thousands clearance between the seal and the crank.

So plenty of well meaning advice out there, but I would prefer to hear from our group of their experiences of how they installed the seal to work effectively.

regards,

Dave

[MarekH]

Soak the seal before you attempt to work it.

Keep sizing it using the tool until you are blue in the face.

The tool ought to be the same size as the crank so that the oil groove ought not to be a factor in contact with the seal. The example you gave has a seal which hasn't been sized enough as it has the imprint of the groove on it - logic says that this will get cut off as soon as the engine spins up.

When measured via another website, various sizing tools turned out to be 1-2 thou smaller than the crank which implies that there may be some production tolerance coming into play.

There has been plenty of discussion on the topic on the jag-lovers.org site if you look for it regarding the v12.

kind regards
Marek

[christopher storey]

Absolutely essential to soak the seal beforehand. I put them in a jiffy bag filled with oil for a week! As far as rolling it in is concerned, the purist would use the sizing tool ( can be hired from the JEC) , but the man who does my machining has always sworn by using the crank itself , ( that way ensuring that you have it done to the working as opposed to theoretical size ) and the last time I did this it worked perfectly, even though the process was tedious and long winded, taking me the best part of an afternoon .

PS although I have been guilty of trimming the ends , the best practitioners insist that you must NEVER trim an end, but must keep rolling and rolling until there is no end left to trim . I have a nasty feeling that they are right, but I think I have got away with it in the past

PPS No idea about the holes in the ends - I am certain there are no pins to be inserted

[Alty Ian]

Chris. Barry did that on mine but it leaks a bit at present, however its only a seep and hasnt got any worse,.. yet.

[abowie]

I was of the understanding that the new seals don't require soaking.

You need the correct sizing tool. The ends do seem to need trimming; a flat razor blade is a good tool.

You can temper my advice by my experience that they all leak anyway to a greater or lesser extent.

[mooney1el]

This past summer,I went through the same quest for the "proper" procedure for the spare engine I was building. Some said soak the seal, others said install it dry, but most credible sources said in any case, you have to use the seal sizing tool.

Being the spend thrift and having the awesome opportunity to correspond with an Australian builder, I was able to make my own tool using the dimensions provided. It was a fairly simple lathe operation; but I guess everyone doesn't have that equipment available. I turned the tool from DOM tube that I had already in my stash. Here in the States, the proper Churchill tool is available for loan from JCNA for a very reasonable sum, but since I have two engines to do and am dong them at a leisurely pace, I made my own.

Since there was no consensus on soaking or no soaking, I had to choose. I decided that soaking couldn't hurt, but I went one step further. I placed the seals in a cup with motor oil, then placed the cup in a vacuum desiccator and pulled a vacuum in order to "push" the oil into any pores or voids in the seal. I will say that there was some bubbles as the vacuum was applied so there are some cavities in the seal. BTW, these were the not the white seals,, but rather the darker ones that come in the standard gasket kits.

Even with the oiling of the seal halves and rolling the seals into the carriers, I found that i was too difficult to push the tool into the assembled carrier. So, what I ended up doing was to put the seal into the lower carrier, place the tool into the rear bearing cap then assemble the upper carrier in place. This allowed me to turn the tool and set the seal. At first, the seal was not properly seated but I didn't realize it and trimmed the end to be flat with the carrier surface. I ruined the seal by not taking my time and making sure everything was seated. I had to turn the tool through quite a few rotations to actually set the seal. In the end, with new seals, I found that I did not need to trim the ends at all, they were perfect. Once realizing this, the lower seal went without complication and no trimming.


Richard Gray

[mgcjag]

Hi Richard...would be great if you could post drawing /dimensions of the tool you made here for future use....