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Triumph Repair/Triumph Spitfire bell housing oil seal


I am fitting a lip style oil seal to the bell housing of my Spitfire, the new seal looks to be to large, I have destroyed one on my first attempt.

I was trying to chap it in using a socket that fitted inside the housing, to my eye the seal looked to big but off i went after a few soft taps i gave it a good hit and the thing deformed. have a new one and looking for some help.
the housing has an initial recess that the seal sits in VERY easily, the seal sits proud not like the one I removed. the inner recess is very tight but that's where the old one sat?
Any ideas what I should do.



Hi Kevin,

This type of problem shows up on other parts of the cars so in delerships we first look at the numbers on the old and new seal to be sure the sizes matches because seals like bearings have the size written on the seal. If the old seal has been discarded and you can't check it now, you need to get a caliper to accuratly measure the bore in the case and look at the new seal size written on the seal to see if they match. Parts suppliers often get the wrong seal or bearing for the application. (the size will often be in mm )

Also it is better to use a flat steel of aluminum plate the put against the seal to drive it in. If you do a lot of your own work it might pay you to purchase a set of seal drivers which is just a drift and severls different size plates to fit the end. They are useful to install bearing races also. It is not advisable to put something that fits inside the seal to drive it on. This will warp and damage most any seal even if the size is correct. Ypu most use something that is flat and large enough to seat all the way across the seal to distribute the load on the whole metal part of the seal when driving it in.

Another point you want to look at is the case should have a small chamfered edge on the bore where the seal goes. I have found some cases that the edge was sharp so I would then use a rotarery tool to cut a small champher on the edge. This is not too necessary when the seal has exposed metal on the outside but some seals have a rubber coating on the metal part of the seal and a sharp edge will cut into the coating and make it difficult to get the seal inplace. A little lube also helps get a seal in place. Always point the open lip of any seal toward the oil that it is trying to hold in. Some front transmission seals are double lip seals so you have to point the larger open lip toward the oil and the small lip towards the engine.

Let me know,


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Howard M. Fitzcharles III


Triumph TR-4 up & Spitfire, and Engine theory


Dealership line mechanic on MG, Triumph, Jaguar for 15 years, Instructor in commercial mechanics school 2 yr. Product information manager for piston and valve manufacture, Instructor & hotline answer man for import car parts importer 15 yrs.

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