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MG MGB Technical - Front Timing Cover Seal OD ID Width specs ?

Hi Guys,

Would anyone have a front timing cover seal to hand and could post a photo of the seal with all the numbers visable please?

I'm interested in the ID and Width but not the OD as it's for a different application using the MGB front Harmonic Balancer / Pulley.

Many Thanks in advance
Mark
Mark Hester

I can't put my hand on one just now, but the part number 88G561 is the same as a midget, so you might try posting on the Midget board...there's lots of folks over there.
Dave O'Neill 2

OD 2.312

ID 1.562

W 0.375
Chris at Octarine Services

Mark-
The Original Equipment synthetic rubber front crankshaft oil seal is technologically obsolete and should be replaced with a higher performance National brand oil seal (National Part # 1873) as a long-term solution in order to preclude leakage. This elastomeric oil seal is internally reinforced by a stainless steel band instead of an injection-molded plastic ring, offers complete compatibility with either petroleum-based or synthetic oils and can withstand service temperatures up to 4500 Fahrenheit (232.20 Celsius). The PTFE material’s low coefficient of friction ensures performance for shaft speeds up to 4,500 surface feet per minute while its lay-down sealing lip design ensures long life in spite of shaft / bore misalignment and excessive shaft thrust or movement. Installed into a freshly rebuilt engine, it should easily outlast the bearings, making oil leakage from the front crankshaft oil seal of the timing chain cover into something for others to be bothered with.

The OE front crankshaft oil seal (Moss Part # 120-000) for the timing chain cover tends to leak engine oil because there is not a built-in device for ensuring that the oil seal is properly centered with the crankshaft centerline after the oil seal is replaced. A special factory service tool that is slipped onto the crankshaft and into the oil seal after the timing chain cover is installed but before the timing chain cover machine bolts are tightened is supposed to accomplish this. However, I have never seen this tool offered for sale in the United States. However, there is an effective substitute: the crankshaft drive sprocket for the MGB simplex (single row) camshaft drive chain (BMC Part # 12H 4201, Moss Part # 460-425). When its tapered end is slipped onto the crankshaft and into the oil seal, it will center the oil seal perfectly while the timing chain cover is being torqued to its specified settings of 6 Ft-lbs for the ¼” machine bolts and 14 Ft-lbs for the 5/16” machine bolts. Be aware that the flange should have significant flutes pressed in between the holes, and the area around the holes is also shaped in a particular way. Check to be sure that the sealing flange is flat, and not bowed. Be sure to not lose the elliptical washers that are peculiar to the timing chain cover (BMC Part #’s 2K 5197 and 2K 7440). These are necessary for spreading the sealing load evenly across the face of the flange of the timing chain cover. Keep them paired with their respective timing chain cover machine bolts as they have become very hard to obtain. Be careful to not exceed the recommended torque values as warpage of the sealing flange of the timing chain cover is a very possible result.
Stephen Strange

Seal centring is easily achieved using the crank pulley - just slip it into the seal on the cover and offer both up to the engine. Tighten the bolts and the jobs done. I use a cut down one that allows the bottom bolts to be done up with a socket.

The elliptical washers were only fitted to the early flat rimmed covers. Later covers with the reinforcing ribs had round washers.

The elliptical washers are still easily sourced here in the UK.
Chris at Octarine Services

Chris-
Thanks for pointing that out. Where in the UK can the elliptical washers be obtained? Moss Motors doesn't even list them.
Stephen Strange

MGOC - 1/4" oval washer 2K5197 - 5/16" oval washer 2K7440.

The 1/4" ones are also used on A series sumps.
Chris at Octarine Services

Chris-
Thanks. These items are all but unobtainable on this side of the pond. I'll order an extra set first thing tomorrow.
Stephen Strange

This thread was discussed between 01/08/2010 and 11/08/2010

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