[TR] More Differential Questions

[Randall]

> Here's what I've found.. With the input flange on ground (the ass is
> pointing up), holding the axle flanges in my hand I can feel 
> about 5 degrees
> rotational play. Is that a good test? 

I would not call it conclusive, but it seems acceptable to me.

In addition to the backlash in the ring & pinion, you are feeling the play
allowed by wear in the thrust washers.

> If I look at the Bentley manual it appears that the input 
> flange has very
> coarse splines, which may be  the cause of the "easy" 
> rotational slop.

Should not be.  The nut on the input flange should be torqued quite tightly,
meaning the flange cannot move on the splines (at least not under pressure
applied by hand).  If it is moving, I would want to at least remove the
input flange and see how bad the damage is from the flange banging back and
forth on the splines; plus of course torque it down properly when
reinstalling.  (Some later TR6 diffs used a collapsible spacer, but a 4A
diff should have a fixed spacer.)

I would be looking more at smoothness as the differential turns.  With the
output flanges unloaded, the input flange should turn very smoothly.  No
clunks, or gritty feeling, or tight spots.  Don't just spin it, but turn it
slowly through several revolutions. If you hold one output flange (perhaps
by resting it on the ground) and provide some resistance to the other output
flange, the input should still turn smoothly.

The "rebuilt" Stag diff I bought had just a tiny bit of roughness while
turning the input shaft ... this is what I found when I got it apart:
http://tinyurl.com/34ceogt

IF everything checks out OK, I'd probably still change the input seal; and
maybe the output seals if you have access to a press to get them apart.
Even if it wasn't leaking for Skip, seals have a way of getting hard and not
sealing after they have been "lying around".

Randall