Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 My new rear wheel bearings lasted 400km

The new SKF bearings in the rear hub, fitted on the chassis exchange in my M3W, lasted a pathetic 400km. I had supplied FAG 7205-B-2RS-TVP bearings, as recommended on this forum but they got damaged and a similar spec pair of conical SKF bearings were fitted. The boss of RD racing is questioning whether the FAG bearings will be correct given they are also conical contact surface bearings. I would have thought for a rear hub, given that Morgan has chosen not to go for the sensible alternative of conical roller bearings, conical contact ball bearings are the next best choice to reduce lateral movement on the hub. Does anyone know if the original Taiwanese NTN bearings are straight or conical contact. I have my original hub but no bearing puller to extract the original bearings to look. They are sealed as well so may be difficult to ascertain if they are straight or conical contact. What sort of bearing puller would be best, to extract the original bearings from the old hub to check them. I wondered if I could just drift them out, rather than pulling.

I am afraid my suspicion is that the SKF bearings may have been counterfeit, which is why they disintegrated rather than any problem with their spec. Below is a picture of the disintegrated bearing.

https://www.tm-img.com/images/2018/05/16/image27.jpg

Wilson

Wilson
Can't answer the question about the details of the bearing type but can say that they are easily driven out with a long drift as the centre spacer moves enough to get at the inner race.

here's a pic of the bearing box from the bearings I fitted to my first hub while on my way to Ireland four years ago;


Usual reasons for failure are dodgy wheel alignment or inadequate tightening of the spindle leading to dodgy alignment.
Hope this hellps.

Always use quality moly grease too!

High Noon

My Blog: https://ontheroadtonowhereville.wordpress.com/

Sealed bearings...didn't use any grease at all!

NTN bearings are ordinary ball bearings with Viton orange gasket, mine have about 90.000km no problem, I own a NTN game make in Poland with color seal maroon waiting to serve as a replacement.

When you say ordinary do you mean single row radial or single row angular contact? If I can drift them out tomorrow, I can look up the NTN bearings on their website to see what they are. On a rear hub to avoid lateral movement and provide a lateral thrust resistance, angular contact bearings are what would normally be used (a pair set in opposing orientation). Radial bearings are only supposed to take radial loads and minimal axial loading. The axial loadings on the M3W rear hub will be quite high. I have ordered a new pair of the FAG bearings to be sent from Bearing-King in the UK direct to RD racing at the Paul Ricard circuit, as French sources were quoting a three week wait. I just hope I have ordered the correct bearings.

Wilson

All I did when my original bearngs failed was take them to a bearing factor and asked for a direct equivalent, the box in the picture is what they had in stock. Details are here.
I don't think there is a great problem with the original MMC supplied bearings but it is really easy to destroy any of these bearings in service as I mentioned before plus there is one particular other way of destroying bearings in this type of hub and that is to fit them and then realise that the centre spacer is still sitting on the bench at which point you have to drift one of them back out by hammering with a drift on the inner race at which point you have just destroyed the bearing, you need to throw it away and find another new one!.

I would strongly recommend going back to the original type of bearings ie deep groove ball bearings like Calum's
I am no expert but do know the mounting design differs between those and angular contact types.

Sorry to hear of your problems with the rear wheel bearings. I have not used the FAG bearings but others have with good results they say. I have used the SKF Explorer 6205-2RSH with no problems, lubricated, sealed, drift out and in. If they are fitted and installed correctly they shouldn't cause any problems. As I know the SKF Explorer bearings are good and there is some doubt about others, I will remove all references to any others from my next Alternative Part numbers update. I do hope your M3W settles down soon Wilson, it has been a saga.

The thought is that the new type black hub needs an extra collar to hold the bearings in the correct alignment. The garage is getting this machined and hopefully should be done by the time the FAG bearings arrive from the UK. The garage owner was dubious that conical track bearings should be used but I am certain from working on racing cars for close to 50 years, that there is no alternative (other than what should have been fitted, which is conical track tapered roller bearings). Raphy who will actually be doing the work on the car, confirms the FAG bearings I have ordered are the right ones. If anyone can sort this out it is Raphy. Raphy has had no trouble with the FAG bearings in his car for far larger mileages than I do.

Wilson