[Mgs] Tale of the rear axle

Barney Gaylord barneymg at mgaguru.com
Sun Apr 17 20:28:15 MDT 2011


David,

All MGA and early MGB with banjo type rear axle originally used all 
brass thrust washers in the dfferential.  These are generally long 
lived, like 200,000+ miles.  My MGA went 250,000 miles before I 
renewed these parts.

Late model MGB, 1968 on and all MGB-GT with the Salsbury tube-type 
rear axle use brass for the spherical thrust washers and fiber for 
the larger flat side thrust washers.  The fiber thrust washers are 
generally short lived, like maybe 50,000 miles to the point where 
they litterally dissolve and disapper.  These are notorious for the 
clunk and need to be remewed periodically (too often).

Some time ago Moss Motors (and maybe some other vendors) made the 
notoriously bone-headed decision to change the earlier brass side 
washers to fiber material for replaceemant parts.  I suppose this 
reduces manufacturing cost, keeps retail price down (maybe), 
guarantees early failure, repeat sales, repeated high labor cost, and 
PO'd customers.  25% worn brass washers will last a lot longer in 
service than new fiber washers.  Facing this circumstance I'd throw 
the fiber washers in the dust bin (or send them back) and reinstall 
the brass washers, as long as they are still serviceable.  Meanwhile 
grovel and beg for a source for brass replacement thrust washers.

On the flip side, if you're talking about a late model MGB, I think 
they always had fiber washers for the flat parts on the side 
gears.  I'm surprised that you mention orginal brass parts 
there.  Most often by the time the clunk gets bad enough to fix those 
fiber washers are simply gone, and sometimes no trace of them in the 
oil.  Perhaps you assumed that those (missing) parts were supposed to 
be brass when they were always fiber.

It is my humble opinion and best wishes to the MG community that the 
later fiber parts should have been changed to brass for replacement 
parts, and the earlier brass parts should have remained in brass and 
should never have been changed to fiber.  I would gladly pay 2x or 3x 
the price for brass thrust washers if necessary in the interest of 
never having to change them again.  Are you listening, Moss Motors?

Barney Gaylord
1958 MGA with an attitude (and 387,000 miles)
http://MGAguru.com


At 09:45 PM 4/17/2011 +0000, Councill, David wrote:
>I have progressed past this point. I was packaging up the slide hammer to
>return to HF but decided to give it a try again with the two arm puller using
>the 2 remaining arms. Several whacks and it popped out.
>
>I have pulled out the gears and washers. Problem is that there is a copper
>washer behind the differential gears, very close to the same size as the new
>fiber thrust washers.  I see no reference or mention of this piece unless it
>is the same, just different material. Should I be using both or just the fiber
>one, moss part 267-140?
>....


>-----Original Message-----
>From: mgs-bounces at autox.team.net [mailto:mgs-bounces at autox.team.net] On Behalf
>Of Stephen West-Fisher
>Sent: Sunday, April 17, 2011 2:51 PM
>To: mgs at Autox.Team.Net
>Subject: Re: [Mgs] Tale of the rear axle
>
>The rear bearing is a press fit.
>I can't visualize it now (it's been a long time) but you can space out the
>drive flange with something and use an impact wrench on the axle nut to pull
>the axle and bearing.
>....


>-----Original Message-----
>From: mgs-bounces at autox.team.net [mailto:mgs-bounces at autox.team.net] On Behalf
>Of Councill, David
>Sent: Sunday, April 17, 2011 2:55 PM
>To: mgs at Autox.Team.Net
>Subject: [Mgs] Tale of the rear axle
>
>I am partway into a rear axle thrust washer replacement. I am now at the stage
>of trying to pull out one of the half shafts.


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