<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>Mike</div><div id="AppleMailSignature">The hub with a groove for an O-ring is off a BT7 or later. You need the spacer to be able to squeeze the bearing inside the hub, so that it doesn't spin. The bearing/spacer combination should be slightly larger than the space for it inside the hub, can't remember exactly but it's a question of a few thou. Check the workshop manual. I can't envisage that you get any problem by mixing these to hubs.</div><div id="AppleMailSignature"><br></div><div id="AppleMailSignature">Per<br><br>Skickat från min iPhone</div><div><br>12 sep. 2017 kl. 22:30 skrev Michael MacLean <<a href="mailto:rrengineer.mike@att.net">rrengineer.mike@att.net</a>>:<br><br></div><blockquote type="cite"><div><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:16px"><div id="yui_3_16_0_ym19_1_1505247969788_3187" dir="ltr">Now that I have the axle hubs off the rear axle to replace the bearings and seal I find I have two different hubs on the same axle. One has an O-Ring to seal beneath the gasket and the other has no such circular groove for an O-Ring. I am sure the one with the O-Ring is original to the car (BN2) but what is the other one off of? Do I need a matching hub with an circular groove for an O-Ring or will it be OK to mix and match? BY the way, neither of them had the bearing spacer. Is that really needed?<br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1505247969788_3344">Mike MacLean</div></div></div></blockquote></body></html>