Lancia Motor Club

Model Technical and Interest => Aprilia, Ardennes and Ardea => Topic started by: davidwheeler on 16 October, 2023, 06:43:53 PM



Title: Wheel bearings.
Post by: davidwheeler on 16 October, 2023, 06:43:53 PM
Please can someone inform me of the numbers/dimensions of the front and rear wheel bearings for my Aprilia?   It would be nice to have the bearings before I take it all apart.


Title: Re: Wheel bearings.
Post by: Sliding Pillar on 16 October, 2023, 08:12:06 PM
Front: inner SKF 6306
Outer 6204

Rear: inner 6205
Outer 6306


Title: Re: Wheel bearings.
Post by: davidwheeler on 18 October, 2023, 05:48:51 PM
Thank you.


Title: Re: Wheel bearings.
Post by: chriswgawne on 19 October, 2023, 06:55:05 AM
Attached are photos from my 1953 RIV Bearing reference book for Lancia Aprilia  showing references and dimensions
It doesnt appear that front outer and rear inner are the same?
Chris


Title: Re: Wheel bearings.
Post by: davidwheeler on 19 October, 2023, 09:19:14 AM
Aaargh, I have just ordered bearings.  We shall see.
Next question - how do I dismantle the rear bearings?  Is there a special tool to undo things?
I am assuming that 38-74039 unscrews which may be difficult after nearly 90 years.


Title: Re: Wheel bearings.
Post by: davidwheeler on 19 October, 2023, 11:27:39 AM
Similarly, 38-73520 for the front.


Title: Re: Wheel bearings.
Post by: Jay on 19 October, 2023, 03:43:22 PM
As you say after nearly 90 years it all become seized and very difficult, regarding the front hub the bearings are in the drum so copied Williamís idea https://www.lancia.myzen.co.uk/forum/index.php?topic=9253.15 (bottom of page) but still needed heat and a lot for force to remove 38-73520, especially on one side. Regarding the rear I used my puller as shown, which did the trick, although removing the flange was far more difficult and again needed heat. Then as you say, you can undo 38-74039 which I used a pin/hook spanner and wasnít so bad compared to the rest, plus the retaining plate on the inner shaft.   

Next question did you buy open as per original or sealed bearings as they now use.


Title: Re: Wheel bearings.
Post by: chriswgawne on 19 October, 2023, 05:26:32 PM
I am sorry I didnt reply to your email earlier David but I very rarely look at my RIV catalogue ( or even remember I have it!) and I know nothing about Aprilias.
But I had occasion to double check an Aurelia transaxle bearing as the English manual I have told me that all
'1st srs' Aurelias up to 5th srs B20 and B24S Convertible  used the same particular mainshaft bearing whereas I had come across 2 types yesterday. I went to check my RIV catalogue (which confirmed the fact that there were 2 types used, slightly different) and whilst I had it open I though i would check your Aprilia data.
Perhaps you would let me know the outcome when you come to fit the new bearings?
Thanks
Chris


Title: Re: Wheel bearings.
Post by: davidwheeler on 21 October, 2023, 09:51:22 AM
Alas, Dicky Dyer is out of stock every where.    I shall have to see what I can do with some tube and the lathe.    I guess I can press out the shafts before taking off the rings then.   
I have bought steel sealed bearings, I presume they come pre-lubricated?


Title: Re: Wheel bearings.
Post by: welleyes on 24 October, 2023, 03:15:00 PM
Sorry to be pedantic, but do the bearing numbers in the catalogue refer to all Apriliias (from first series one to last series two) or were there significant changes during the life of the Aprilia?

Stuart Tallack


Title: Re: Wheel bearings.
Post by: chriswgawne on 24 October, 2023, 04:45:57 PM
Stuart,
The 3 pages from my 1953 RIV Bearing catalogue which I posted above are all the info I have. You will have to seek answers from an Aprilia expert.
Chris


Title: Re: Wheel bearings.
Post by: simonandjuliet on 25 October, 2023, 04:16:07 PM
I am away so don't have the dimensions to hand, but second series cars have bigger rear hubs so the bearings have the same O/D but larger I/D - 5mm diff from memory


Title: Re: Wheel bearings.
Post by: Hendrik on 26 October, 2023, 07:11:20 PM
Next try: I found out for the 2nd series:

anteriori: FAG 6306 and 6204
posteriori: FAG 6205 and 4207BTVH
see list attached