The 'E' Type Forum

Is it necessary to remove the head on a 4.2 when having to remove the crank in order to repair a rear crank seal that is leaking excessively?

I am very familiar with the V12, but the 4.2 is new to me.

From what I've seen it seems one has to remove the head to remove the front timing cover before you can remove the crank.

If you need to remove the crank then you would need to remove the head to dismantle the timing gear and chains. The bottom chain would stop the crank removal not the timing cover. It maybe that just fitting a new lower half seal would cure your oil leak but not worth the risk, better to do the job properly and just once.

I've fitted lots of rear seals but only ever on full rebuilds so I've never tried to do what you propose.

You can get the front timing cover off without removing the head; I have done this once albeit on a newly rebuilt engine to fix the a problem with the front seal.

I'm not sure whether if you disconnect the top chains from the cams there's going to be enough slack in them to get them off the intermediate sprocket so you can get the bottom chain off.

If you can get the top chain off you should be able to get the lower chain off and therefore take the crank out. Of course If you have link chains that would make it a lot easier.

My concern would be ensuring a proper seal at the top of the timing cover on reassembly, especially the front section of the head gasket. On an engine that has some miles on it that gasket might well be well stuck and get damaged when you try to remove the timing cover. You might end up swapping one set of leaks for another.

As you have the engine out and on a stand, why not give it a go and see how it looks? At worst you do end up removing the head and you have lost nothing.

Thank you chaps! Its clear to me that a proper job on repairing that rear crank seal will require almost a full rebuild. Need to advise the owner accordingly.

To be honest, if it was my car, I'd pull the whole thing completely to bits, measure everything and refurbish accordingly. Money well spent and then you have a reliable drive train for the rest of your life.

Hi Philip...are you really sure its the rear crank seal.....check the camshaft banjo oil connections to the rear of the head...leaks here are common and run down the back.....also the rear sump gasket as mentioned above.....Steve

mgcjag wrote: ↑

Fri Oct 09, 2020 7:43 am

Hi Philip...are you really sure its the rear crank seal.....check the camshaft banjo oil connections to the rear of the head...leaks here are common and run down the back.....also the rear sump gasket as mentioned above.....Steve

Ah, the sump gasket.....

Have not considered that possibility. Would it somehow be possible to confirm that the leak is coming from the sump gasket and not the rear crank seal?

Also, can a sump gasket repair be done without removing that "cross brace" that also anchors the torsion bars?

No you don't have to remove the reaction plate to get the sump off - you do have to turn the crankshaft to get the webs into the right position to give you enough room to drop the sump though.
Check what is leaking first though - (best done with a lift) -

Barrie

Hi Philip.....what facilities do you have......removeing the sump is quite straight forward if you have a 2/4 post lift..quite difficult to tell if its a rear sump gasket or crank seal an inspection through the bellhouseing with a flexi camera is the only real way .....however considering a rear crank is a full strip down that will snowball into other work i would gamble on doing the sump..........far easier to disconnect the front hubs at the top wishbones and get the tension out of the torsion bars......then the reaction plate your refering to can come off easily.....this makes the off/on of the sump a simpler job.....but check those rear cam banjos first they can leak enough oil to make you think its a rear seal.....Steve

mgcjag wrote: ↑

Fri Oct 09, 2020 12:46 pm

..but check those rear cam banjos first they can leak enough oil to make you think its a rear seal.....Steve

Yep, I had loads coming from there at one time and thought it was coming from lower down.

I have a pit in my garage, so working under the car is no hassle.

I cleaned around all three banjo bolts and then tightened them a smidge just for good measure, but they were rather tight already. There were signs of oiliness back against the head, but that could have come out the tach generator long ago. So let's see...

There have obviously been a lot of new ideas & ingenuity put into solving the problems with the XKE rear crankshaft seals. Some are effective & others not so & it is easy to understand that there are reasons why.

However, there are more effective & more positive sealing results being achieved by the unique F-Type Seal designs being used by GST Racing Seals in similar applications in older US engines, such as Chevy, Ford, Buick Chrysler, etc.

All of the seals which have been introduced over the last 10-12 years have been totally effective at eliminating customer oil leakage problems. Rather interestingly, many of the seal groove housings in these old US engine blocks are similar to the old Jaguar rope seal grooves, so the same concept should be equally effective if applied to the XKE engines.

After such a long period of time & with such a success record we can reasonably claim to have gained expertise in these difficult seal applications.

If you would like help or advice on any seal applications please feel welcome to contact us direct on info@gstracing.co.uk

Hi

I did mention GST in a recent thread regarding seals in particular a stretch rear crank seal offered by Rob Beere: http://forum.etypeuk.com/viewtopic.php? ... fbb59db186

is this one of your seals sold by others.....
are you the actual manufacturer or reseller...
do your seals require machining of the crank.....
what experience do you have with your seals in E Type's.......

Thanks...Steve

Hi Steve,
The seals which we supply are custom-designed by us to suit each application.
We need someone to provide us with details of the seal groove dimensions in the engine block & rear bearing carrier following which we will complete details for manufacturing the new seals.
In the past we did supply seals to JD Classics to suit their seal carrier.
It would be useful if we could work with an Engine Builder for this project.

Ah ok.....i thought that you had rear seals ready to go for a standar E type crank as opposed to intending to develope something.....so the stretch seal is not yours?...Steve

Hi

Add the two sump bolts nearest to the rear crank seal housing to the list of possible oil leaks.
I also have a problem with the cam banjo bolts leaking as has already been mentioned. I've tried everything to stop them leaking, all to no avail.
Does anyone know if the braided hoses are more liable to leaks than the original rigid pipe?

Cheers

If you were working with JD Classics, you can forget it . No one trusts anything or anyone who had anything to do with JD Classics

Check this Recent post for discussion on rear Sump Seal replacement. Not that big a job.

Which seal to use on sump gasket

I thought my crank seal gave up and it was the Sump seal that had opened up for some reason.

GST # 11220 fits the rope seal groove & requires the crank to be ground down to Diameter 3.140" (79.75 mm).
It is the same seal used in USA to successfully solve the historic oil leakage problems in the Ford 460 engines.