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YA & T Differential by John Harris

After hearing a whine from my back axle and crawling underneath to have a look I decided to replace the pinion bearings on the differential.


The back axles in the YA/T and YB models are different in as much as the later YB has the TD back axle. Thus the differentials are also different. I found this out when my half shaft broke I had to get new ones made.


Having contacted my usual and reliable parts supplier I found that all bearings and seals etc. were available except on of them, the rear and larger one, was very expensive and could be supplied by them and was advised to seek out a supplier myself.




Cross Section of the YA/t differential (courtesy of the workshop manual)


Just to note that the supplier catalogue shows an exploded view of the Y back axle /diff’ and shows both pinion bearings to be the same whereas the diagram in the MG Y Type Workshop Manual shows quite clearly they are different.


I first sought the advice of Neil Cairns of the MG CC Y Register who put me in touch with another Y Type owner who kindly rummaged through his bits and sent me some photographs of the boxes he kept having done the same exercise. He said that they were Timken bearings felt that they were correct but suggested I check. I enquired of the Vintage Bearing Company by phone and was quoted some prices. The price for the front (smallest) bearing seemed to fall into line with what I was expecting but the price for the rear (larger) bearing seemed very much cheaper than expected so at the time I was still uncertain about this one.


I had hoped to get all bearings and seals etc together rather than stripping out the diff’ first before ordering these bearings. However, as luck would have it, and a word in my shell like from Chris Callaghan (thanks Chris), I was able to buy a complete diff’ assembly from E-bay, Manna from Heaven.


I was therefore able to strip this one, which looked as if it had never been taken apart, and thus get references direct from them. I must mention that the outer ring and the inner roller assembly, while being sold together, have their own numbers.



I carefully dissembled this spare diff’ and found that they were SKEFCO bearings so I was able to obtain the numbers. These are:


REAR BEARING (i.e. Nearest to the Crown wheel))


Outer track –                            Bearing number – SKEFCO 2K2420            S-T-E-E


Inner race/roller assembly     Bearing number – SKEFCO 2K2473X         S-T-F-E


FRONT BEARING (i.e.nearest to the prop-shaft UJ)


Outer track –                           Bearing number – SKEFCO 7K15250          S-T-F-E


Inner race/roller assembly     Bearing number – SKEFCO 2K15100S        S-T-F-E


In addition to this I took overall measurements with an annotated diagram to send to a number of bearing companies for prices.


Below listed are the companies I canvassed, there are other companies I’m sure. The price range can bee seen in the table below, which includes carriage and VAT just to give you an overall cost to you. As you can see, prices vary widely.


  Company Cost including + P&P & VAT Make
    (Prices at September 2015)
  NTG (last info from website) Only do one of them Not stated
  Stateline Bearings Unable to help —————
  Simply Bearings Ltd Unable to help —————
  The Vintage Bearing Company £193.00 Timken
  Bearing Shop UK Unable to help —————
  BearingsRus £195.50 Timken/SKF
  The Bearing Company £440.53 Not stated
  FW Thornton Bearings Unable to help —————
  **AC Belting £234.72 Timken
  JFB Bearings Unable to help —————

The data in this table was put together from quotations via Email from the companies approached.


** AC Bearings offered 7K15250K for the front bearing stating (we can only supply the K type of this, but this just means it is a bigger radius and should not effect what your using it for).


Take your pick from these but search further if you wish. Good hunting.