MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MG Y Type - Replacement Half-Shafts

I believe that the second and third batches of half shafts produced by the Octagon Car Club (OCC) are shorter than they should be by around 3/8”.

The first batch was commissioned by a private individual before being taken over by the OCC and is shown on the drawing to be 25¼” long. This only just reaches the end of the pinion, but should be adequate in my view. Original half shafts are about 25 3/8” long and the latest replacements are about 25 1/16”. This means that only around 80% of the pinion is engaging with it – in my view a far from satisfactory position. A Y Type owning mechanical engineer is going to return his recently purchased set. One wonders what new and unusual stresses will be placed on the ageing pinion.

I thought that this information should be made more widely known so that at least purchasers can make up their own minds about fitting. I should add that I know of a Y Type with the new half-shafts fitted that has covered over 1000 miles on a run recently without difficulty.

I still want a new set and hope that the OCC can sort out a way of reconstructing the half-shafts to the original specification.
M D SILK

I bought a pair of new half shafts for my TF from Dave Clark in Arizona. These are made from superior material and deliberately made slightly smaller diameter than the originals. They are reputed to be the best available, and there is no reported case of failure though many have been sold and fitted - including many competition vehicles. They are also 3/16" shorter than the originals that they replace. It seems to me that this suggests that there is no issue with the length.
Dave H
Dave Hill

Thanks for your comment, Dave. Very interesting that other replacement half shafts are shorter than an original - although I can see no logical reason for it! Whether the length matters on your shafts must depend on where they sit in relation to the pinions in your differential. If you have 3/16" to spare beyond the pinion then I agree it shouldn't be a problem. If you haven't then who knows? Hopefuly your supplier knows his stuff.

I have now had confirmation from another owner that he has a spare half shaft that is 25 5/16" long and I have one that is 25 1/4" and one that is 25 5/16" long. However, on the shorter one it is clear that the one inch of 'mating' length finishes right at the end of the the splines near the end chamfer, whereas the ones I have refitted at 25 3/8" long definitely had a short length (about 1/16" at least) of 'untouched' potential mating area. The ends clearly projected into the quite large gap between the two fitted shafts.

So I still maintain that only around 80% of the potential mating area is not being utilised. Given that our cars are now 60+ years old, I see no reason to risk any damage to the differential by imposing unusual stresses on the pinion. But I accept others may see it differently.
Mike Silk

In the final paragraph it should of course say that 'only around 80% of the potential mating area IS being utilised'.
Sorry about that.
Mike Silk

Second hand pair of original ones on eBay http://www.ebay.co.uk/itm/MG-YA-Half-Shafts-/331702820449?.

While you need to be aware they have already been pre-stressed so should only be used for the side they have been in they will be handy if you break one!

I have no financial or other interest in the sale of these.

Paul
Paul Barrow

Of course the shafts I sell that Dave Hill purchased would only fit the YB which shared the axle from the TF. I did check four used original shafts and they measured 28.125" and my replacements are 28.0625" so Dave I don't know about the 3/16" longer shafts you had.

Paul is right on about the shafts becoming sided once they have been used.

Dave
Dave Clark Arizona

Shorter than the originals Dave, not longer.
Dave H
Dave Hill

Whilst acknowledging the YA half-shafts are different from the YB, the pic on ebay of the aforementioned YA half-shafts for sale appears to show two shafts of different length yet sold as a pair. Is it my eyesight, my computer screen, an optical illusion, the fact that they are different lengths on the same car, or possibly from two different vehicles altogether?
I realize I could send a question to the seller about this particular posting, but would ask for my own educational requirements and possible future needs.

Thanks
Bob - Y6686
RA Barham-Hall

I have now had confirmation from the commissioner of the first batch of replacement half-shafts that they were made to a length of 25 1/4" as specified. He had his back axle apart for repair and measured them for me.
I know that one set from the second batch were only 25 1/16" or 25 1/32" long, and this is comparable to the lengths of those from the third batch.
Given that some shafts I have had measured were 25 5/16" long or more, I leave it to you to decide whether you wish to purchase them. I have chosen not to and have obtained a refund.
Mike Silk

This thread was discussed between 07/10/2015 and 01/03/2016

MG MG Y Type index

This thread is from the archives. Join the live MG MG Y Type BBS now