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MG MG Y Type - Oil leak from split pin

I understand it is normal to have oil leak from the split pin underneath the transmission, but I have a lot of oil coming out of there. It's a steady drip, around one drip per second.

Is it also safe to assume that this may be at least partly to blame for my clutch slipping up steep grades? If I let the rpms drop down, the clutch catches again but if I give it gas it will again begine to slip. When the clutch cools off it's fine but when hot, for example driving on the freeway for a while, it will slip going up grades.
Steve Simmons

Been there.The purpose of the split pin is to keep the hole open so that the oil can leak out and not effect the clutch. The original rear oil seal was basic and wears fairly quickly. There are now after market seals.I first went with the Moss seal. It was a disaster,the oil puddle went from the size of a saucer to that of a dinner plate. Moss has since come out with an"improved " version but I wouldn't use it without hearing a lot of ringing endorsements.
Replaced the Moss seal with a Volvo seal developed by Bob Schapple in Australia. It has worked well over about 6-8000 miles. Phone Bruce Smith or another of the Aussie parts suppliers which you can get from the main MG page.
On the TC I used the Andrew Bradley seal which is a Chev or GMC seal. For a description of this seal go to the T-ABC site. It also works though I don't have that many miles on the TC as yet.Both the Schapple and Bradley seals require some machine work to be done to the engine. While there have machine work done to the front so as to fit the Moss lip seal which does work if properly machined.Terry
Terry O'Brien

My YA rear oil seal was replaced in the UK using a Brown and Gammons kit and has been brilliant. Not cheap, as the engine has to come out - therefore hood off, headlamps off, bar out, grille off, radiator out first and then all of that has to go back. The back of the engine had to be machined as well as the crank (it was ovalled). Also, the starter ring had to be replaced ... and so on.

If you want a Stateside seal, I am happy to tell you the route I am going down with the engine rebuild on my YT which I am doing. I am going to use a seal provided by a Washingtonian who has had many XPAG engined cars, including a Y and a YT!!

The guy is actually ex-Californian, and is Ermit Starnes. Ermit can be contacted by email at erstar@comcast.net. FYI I am not on a commission, I have met the guy and he is a very straight man and I am looking forward to working with him on this project.

While I have not yet installed the seal, or had the proof of the pudding, I dont think I am going to need it. I have full confidence that Ermit's seal will be fine and it is a fraction of the cost of Moss orBrown and Gammons ones.

If you email me off line I will give you my phone number and you can talk to me about this more.

Paul
Paul Barrow

Ack! This sounds like a project larger than I had hoped for. I may have to tie a cofee can under the car with an elecric oil pump to spit back in what comes out.

I do know the bottom end was redone about 15K miles ago, but that was also 30 years ago! Oh well, I'll just buy a larger drip pan and a boatload of motor oil for the time being.
Steve Simmons

Steve - The boat load of oil may not be necessary, It doesn't take a very large leak to produce a lot of oil on the ground. The are a couple of other posibilities, other than a bad rear seal. One of them is the core plug at the end of the cam may have come loose and the other is that the sump gaskets may not have been replaced properly. I will send you some information on the latter. If the leak has just started, I would not suspect either the seal or the gasket, but the core plug for the camshaft would certainly be suspect. If the leak has always been there, it could be the seal or the gasket or the core plug. I have not had a problem with the original seal on our TD over the 30+ years that we have had it, so they can be made to work properly. Good luck - Dave
David DuBois

It has been there since we got the car but seems to be worse now. Last time I pulled the car out of the garage the oil pan was full!

I don't mind pulling it apart, but the problem is that I have no idea what I'm doing and I'd hate to screw it up and have to pull it all again!
Steve Simmons

Steve,

Worry not - always look on the bright side - can you make it drop MORE oil? I doubt it.

The thing to do if you are not sure is a)go slowly, and b) be guided by those who have been there before.

Between Ermit, Dave and myself, I think we will look after you. The biggest problem is knowing your own limitations, and that is the first step to success. The second is a willingness to try new things. After that ... it gets easier!

If you wanted to see where it is coming from without taking the engine out then remove the gearbox (take out the front door check strap cotter pin so that you can fold the door right back, remove front seats and carpet, remove gearbox tunnel house, prop up gearbox with trolley jack, remove drive shaft after marking up faces so you can reassemble, then carefully remove the bolts holding the bell house to the engine and the earth strap [dont forget to reconnect this later] and pull the gearbox through the front door.) You can then see the flywheel and remove it to see where the dripping is coming from.

Before you stick it back together a)check the faces of the clutch for wear and oil contamination and replace as necessary, b) check the thrust bearing too while you can and replace if necessary, replace the earth strap and c) dont over tighten the bolts into the engine as the last thing you want to do is strip the threads.

If after removal of the gearbox you need to take the engine out just be very careful removing the nuts on the headlamp bracket studs that you dont shear them off. Not the end of the world if you do you will just have to have new stud extensions heli-arched onto the stumps.

Go easy and keep in touch.

Paul
Paul Barrow

Steve,

I.v mailed you an article about XPAG oil leaks and the author preaches that if the original cork seal is correctly and carefully replaced oil leaks shouldn't be excessive.

There's also a theory about oil being siphoned out by a oil return pipe (I'm writing from memory now, so please excuse me for inaccuracies).

IIRC There's a pipe that returns the oil from the rear crankshaftbearing to the sump. Some people say that the pipe is too long, and hangs into the oilreservoir when the engine is not running.

If the rear seal is leaking, normally it would "run ut of oil" if the engine is not running. But if the oil is replenished by syphonic action by mentioned pipe hanging into the sump, a steady drip could be the result.

So Steve, maybe you should check with a much lower oil level if it still drips. If not, you should shorten the return pipe when you have the sump off for oilseal-replacement. So this is not the cause of the leak, but it causes the leaking to continue when it could stop.
Willem van der Veer

I am curious Willem, who is the author of the article you have? If it is not by Skip Barnes of VMG in california, I would like a copy of it if you would be so kind as to e-mail it to me. Thank you - Dave
David DuBois

Dave-
This was extensively addressed in the TD threads earlier last year. The recomendation was to shorten the offending pipe to prevent the siphon.
Safety Fast
Paul
YB,TDs,etc.
Paul

The article that I was inquiring about is the first one referred to about the original cork seal being correctly and carefully replaced. I was curious because I have been sending out an article by Skip Burns (with his permission) for several years to anyone having a problem with rear seal leaks. The rear main oil leak is an issue that has intrigued me for some time as I have never had a problem with the engines in our TD, both of which operated fine with the original seal, while so many others seem to have nothing but problems with the original seal. I have often wondered if one of the biggest problems is that, with the availability of the Moss seal, Bradley seal, and various and sundry other "modern lip seals" we have forgotten the previous wisdom that was preached to us all the time, about the proper and careful assembly of the gaskets around the sump to keep from having excessive leakage from the rear main seal. I have not heard that discussed at all since the various lip seals have come into use on the engines (all with varying degrees of success from my observation). Cheers - Dave
David DuBois

Dave, it is the article by Skip Burns, which I found somewhere on the Internet.
Willem van der Veer

Willem - Thanks for the reply. From your description, I thought that the article you were talking about might be the one from Skip. That is one of the best "back to basics" article regarding the rear crankshaft seals I have seen recently and it look like my efforts to get it spread around has paid off. Cheers - Dave
David DuBois

"The original rear oil seal was basic and wears fairly quickly."

Not true, there is no oil seal to wear. The sealing is by a reverse-scroll ground into the crank, that runs inside a volute casing with just 3 thou. of an inch clearance. If the crank has been reground, and some fool has ground this scroll as well, ( it happens,) then the seal will not work. Cast into the crank is an oil thrower, and sometimes its drainage area is full of old carbon.

The scroll seal is based on a 2000 year old system of pulling water up out of the river Nile in Egypt, and about as efficient. It only works when little oil escapes from the rear bearing. As the bearing wears, so the oil flow from it increases. Eventually the flor is so great the seal cannot cope, so it leaks. Oil will be seen coming from the 'split-pin' in the bottom of the bell housing.

BUT....the rear end of the camshaft, that is sealed by a simple core-plug is also in the bell housing area. If it leaks, you get the same drip from the split pin.

The cure is, either fit a crank with good bearings, and clean out the drainage area, and accept it will drip a little; or fit an expensive neoprene seal that might not work on the poorly machined surface of the crank boss.

Or check that the camshaft core plug is sealing OK.

Neil.
Neil Cairns

A new page has been added to www.mgytypes.org to try to consolidate the knowledge base on oil leaks and seals. May be of interest to folk.

Paul
Paul Barrow

This thread was discussed between 01/01/2006 and 09/01/2006

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