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MG TD TF 1500 - 51 TD Rear oil seal info & pix?

I've been digging through the archives for information on doing the gaskets and front and rear seals when putting the engine back together. There's a great page on installing the sump & timing cover gaskets, and I found a good page (with photos from a Jag engine) showing how to install a good rope seal (I don't want to use the new type, would prefer to just do it right with the old style seal) but haven't found any info on the rear seal that was a good "how-to"... plenty on the new Moss speedisleeve seals, but I won't be installing that. Can anyone point me to a good thread on the subject of installing the rear seal correctly with pix?
Much appreciated...
I won't get to this for a couple of weeks yet, but it's time to do the 'due diligence' now :)

FYI for anyone also looking:
http://www.chicagolandmgclub.com/techtips/mgt/oil_leak.html
is good but has no pix :(
and this looks very good, for the rope seal:
http://www.vintagevehicle.co.uk/fitting_rope_seals_is_a_bit_of_a.htm
Geoffrey M Baker

The rear seal is that cork one that goes on the pan with the slinger on top if I am not mistaken. I have has the cork seal in for years, not a problem. some folks seem to be fanatical on trying to stop all leaks. easy install on the cork seal just make sure the tabs on it fit right. If it ain't leaking oil, it's out of oil....
TRM Maine

Even with the Moss rear seal you still use the cork lower. When you seal the pan, put extra around the cork tabs. If air can get through a hole, then so can an alarming amount of oil!
Steve Simmons

The block must be line bored to get the main bearing clearance down to .001" or less. This will result in an interference fit between the crankshaft & the oil thrower, as the crankshaft is now higher in the block. The thrower is now hand fitted by scraping, until it no longer contacts the crankshaft.
Once this is done there will be NO oil leaks from the rear of the crankshaft, if the oil pan & cork seal are properly installed. ( it took me a few times to get the oil pan or sump with the cork seal to seal with no leaks)
No lip seal needed.
Len Fanelli



Len is correct, the perfect fit can be achieved by the line bore process, however, one must find a machine shop that knows what they are doing, and has experience with the XPAG engine. Not that easy around rural Kentucky--- believe me I tried.

Geoffrey, I found this web site interesting, and ended up using a similar made tool to check and correct my rear seal surface fit.

http://ttypes.org/ttt2/crankshaft-rear-oil-seal


Please give me a call, I have some information you may need. Phone 270-384 0344
Richard Cameron

Stupid additional question... seis there a rope seal of some kind fitted into the opening around the crank as show in the picture below?
I ask because I don't have the engine in front of me to look at so I am probably overlooking the obvious....

Geoffrey M Baker

No, there's originally a gasket that goes between the upper oil seal plate and the engine block. The fit around the crankshaft scroll and this oil thrower plate (as MOSS Calls it) is partially what determines how mush oil leaks out. The other lower half of the sealing area is a machined surface on the rear main cap.
Richard Cameron

I have a few diapers under mine held in place by bailing wire. Oh my, how I love bailing wire... so useful.
MAndrus

Len Fanelli wrote:

The block must be line bored to get the main bearing clearance down to .001" or less. This will result in an interference fit between the crankshaft & the oil thrower, as the crankshaft is now higher in the block. The thrower is now hand fitted by scraping, until it no longer contacts the crankshaft.
Once this is done there will be NO oil leaks from the rear of the crankshaft, if the oil pan & cork seal are properly installed. ( it took me a few times to get the oil pan or sump with the cork seal to seal with no leaks)
No lip seal needed.


I want follow Len's advice but i do not understand the process of "line boring". Does it mean that material is removed? Where is it removed and how is it compensated? What shall I tell the machine shop?
W_Mueller

Line boring (align boring) is a fairly expensive machine-shop procedure where the crankshaft saddles and caps are either re-cut or honed so that all are perfectly straight. In an MG engine that means that three crankshaft journals and caps are cut with a boring bar to align in the same plane with the upper oil slinger, which minimizes oil leakage. The bearing retaining pins must be removed. If material must be removed from the bearing caps, the process moves the crankshaft centerline upwards, which alters piston height above the block, etc.

Tom Lange
MGT Repair
t lange

Thank you Tom - now I got it.
W_Mueller

I've been thinking about the facts.

So it is the upper oil slinger which is the only thing responsibel for leaking if clearance is too much?

An oversized slinger which must be scraped would be a proper solution without line boring?


W_Mueller

Line boring the main bearing housings should cost about $ 300 -$ 500. The caps are machined, or milled perhaps .002" to .004" on the parting face, then the bores are like bored to the PROPER size. When this is done the main bearing clearance is reduced to .001" & consequently the upper slinger will need to be hand scraped to fit without an interference fit to the crankshaft. Before doing this measure the main bearing clearance with new bearings and confirming that the crankshaft journals are also the proper size. If it measures at the top limit of .003" line boring is needed, .001" is desired to keep oil leaking to a minimum or zero.
Len Fanelli

Resetting the slingers requires real skill. They are dowelled to the engine and these need to be moved to give zero clearance before being scraped to give the correct running fit. The ends will also need kissing up to compensate for any wear on the bore before the dowels are relocated. All this work can be in vain if the scroll on the crank is worn. If the rear leak isn't so bad a catcher tank will provide a total solution and take ten minutes to fit. Use an old baked beans can and the cost will be zero, something a little better engineered will be a couple of pounds.


Jan T
J Targosz

Has anyone had any success with the JB Weld fix for the rear oil leak?

https://www.mg-cars.org.uk/imgytr/oilleaks.shtml#Rear_Engine_Oil_Seal

Look for this paragraph:

Rear Engine Oil Seal (Otherwise known as "If it works, leave it alone")
by John Seim

Tim
Timothy Burchfield

Geoff.,

All useful info. for you above re the rear oil engine sealing.

I have had great success with the cork seal which is impregnated with rubber. The original cork only seal was not so good.

Also, I use Toyota Gasket Sealant which seems to be a great product.
I have used it on Two(2) TF engines now with no leaks resulting. Care is needed of course particularly where the cork/neoprene seal ends meet the sump gasket.

Cheers
Rob Grantham
TF3719("Aramis"),TF9177("Athos").
Rob Grantham

Hi Geoff:
I tried to email and phone you offline and both kicked back. Have your details changed?
You should google “XPAG oil leaks - and cures” . Dave Dubois put this compendium together and it is a great treatise for using the original style seals.
Please contact me! My details unchanged.
Best regards
Rod Murray
Rod Murray 54TF 3006

Hi Geoffrey,
Yes, the original system works very well if everything is perfect. My dad's Y-Tourer didn't leak a drop and had the standard system.

However, some people seem to have problems whatever they do, so I am guessing there can be another cause for leaks. My guess is that sometimes the rear main cap does not seal perfectly against the block because of machine marks or other imperfections. In fact there are relieved "channels" along the outer edges of the cap recesses. The diagram in the image shows possible routes for oil to leak. The shaded areas should be sealed during assembly with a small amount of silicon or similar.


Note that the diagram is from my old instructions. Ignore the extra bit on the back if applying to the standard system. I once saw a copy of the Moss instructions and as far as I can remember, they did not point out this possible issue.

Bob Schapel


R L Schapel

This thread was discussed between 02/06/2015 and 13/11/2018

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