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+--- Thread: Pinion Assembly (/showthread.php?tid=1732)
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Pinion Assembly - steve davidson - 16-09-2018
Hi all, I’m in the process of rebuilding a differential that was very much the worse for wear. My question is about the locking rings final resting place. When I stripped the unit down the locking ring's flange sat hard against the torque tube (see photo 6236). Now that I’ve installed new bearings the lip is a millimetre or so out from the edge (photo 6573). I’m comfortable that I’ve tightened it up as best can be and if I tap the pinion or the flange end with a copper mallet there appears to be no movement.
My question is this; is it correct that in the first photo the locking ring was it’s "maximum" position and is the new location is ok? My assumption is that the new bearings are slightly wider than the old ones that that’s what’s causing the gap to appear during the rebuild. I guess I could pull it apart again and measure the bearing width but there is a risk that I’d damage the bearings during extraction so I’d like to avoid that. First lesson for me is to be don’t just check bearing diameters, check widths as well.
Thoughts?
Steve and Tate
RE: Pinion Assembly - Stuart Giles - 16-09-2018
Did you get the AC bearings from a bearing factor or similar? The ones Austin used on all but a few late cars are narrower on the outside race than the "off the peg" AC bearings. If you have the standard width bearings, as well as that gap, the pinion mesh will be different by the difference in the width of one of the bearings.
The ones that Seven Workshop (and others) sell are ground down to the correct width.
https://www.theaustinsevenworkshop.com/products/ra0394-pinion-bearings-int-8ljt-ac-thrust
RE: Pinion Assembly - Tony Press - 16-09-2018
(16-09-2018, 04:00 PM)Stuart Giles Wrote: Did you get the AC bearings from a bearing factor or similar? The ones Austin used on all but a few late cars are narrower on the outside race than the "off the peg" AC bearings. If you have the standard width bearings, as well as that gap, the pinion mesh will be different by the difference in the width of one of the bearings.
The ones that Seven Workshop (and others) sell are ground down to the correct width.
https://www.theaustinsevenworkshop.com/products/ra0394-pinion-bearings-int-8ljt-ac-thrust
Spot on Stuart- as with the crankshaft AC bearings. We now have the standard AC bearing outer rings machined to the correct narrow width- ceramic tools apparently - wonders never cease !
Cheers, Tony.
RE: Pinion Assembly - Bob Culver - 17-09-2018
A closer look at the pinion cleaned would be interesting. If that is a wear step at base of teeth, looks like it might have clocked several score million revs.
I suspect the original bearings were stepped to ensure assembly of each bearing facing the right way.
RE: Pinion Assembly - Chris KC - 17-09-2018
Steve, as Stuart and Tony have said, the A/C bearings should be a matched pair ground to size.
The large ring nut when fully tightened should give the outer races of the A/C pair 0.001-0.002" end clearance within the housing - ref A7 Companion p.156 (Austin Service Journal March/April 1932).
RE: Pinion Assembly - Robert Foreman - 17-09-2018
You can always thin the spacer, removing the difference in thickness between the races and also machine up a washer so the gland nut goes up solid
RE: Pinion Assembly - steve davidson - 17-09-2018
(16-09-2018, 04:00 PM)Stuart Giles Wrote: Did you get the AC bearings from a bearing factor or similar? The ones Austin used on all but a few late cars are narrower on the outside race than the "off the peg" AC bearings. If you have the standard width bearings, as well as that gap, the pinion mesh will be different by the difference in the width of one of the bearings.
The ones that Seven Workshop (and others) sell are ground down to the correct width.
https://www.theaustinsevenworkshop.com/products/ra0394-pinion-bearings-int-8ljt-ac-thrust
Hi Stuart, The bearings came from our Club supplier here in Queensland. I think I'll pop the bearings back out for measure. Thanks for the advice.
Steve
RE: Pinion Assembly - Tony Press - 17-09-2018
(17-09-2018, 08:28 AM)steve davidson Wrote:(16-09-2018, 04:00 PM)Stuart Giles Wrote: Did you get the AC bearings from a bearing factor or similar? The ones Austin used on all but a few late cars are narrower on the outside race than the "off the peg" AC bearings. If you have the standard width bearings, as well as that gap, the pinion mesh will be different by the difference in the width of one of the bearings.
The ones that Seven Workshop (and others) sell are ground down to the correct width.
https://www.theaustinsevenworkshop.com/products/ra0394-pinion-bearings-int-8ljt-ac-thrust
Hi Stuart, The bearings came from our Club supplier here in Queensland. I think I'll pop the bearings back out for measure. Thanks for the advice.
Steve
Hi Steve, the specially machined pair with narrow outer rings are held in the Melbourne Club Spares as Part Number 0394a - sold only as a pair.
Tony.
RE: Pinion Assembly - Bob Culver - 17-09-2018
Assuming you have the correct narrowed bearings, is one reversed?
RE: Pinion Assembly - steve davidson - 17-09-2018
(17-09-2018, 10:56 AM)Bob Culver Wrote: Assuming you have the correct narrowed bearings, is one reversed?
Hi Bob, I put them back in the same orientation that the old ones came out, but who's to know if the original ones where correct. It was it a pretty sad state when I got my hands on it. I'll strip them back out tomorrow evening, take a few measurements and see where we are at. Thanks for the responses.