Re: UUC Delrin front shifting arm "round" bushings: heads up

["Rob Levinson" <always_coca-cola@xxxxxxxxxxxxx>]

It helps if you understand how the carrier assembly is made and how the
bushings and pin fit and work in conjunction with each other rather than
independently.

The web site does not say they are within .001" of each other.  The web site
says we can *control* the machining to that tolerance.  And we do.

The mounting pin diameter is exactly .391".  The bushings are machined to
.393".  This difference is deliberate and the reason is obvious once you
know how the original BMW parts are made and the fitment tolerances and
variances that can be encountered.

The factory original carrier is cast aluminum.  This casting done in two
pieces, a left and right side.  The two halves do not always line up exactly
even (in fact, they rarely do in this part).

If you were to machine the ID of the bushing to the same .391" as the pin,
you would have trouble getting the pin on and cursing like a drunken sailor.
If you were to machine it to .392", you could fit the pin through both
bushings... but you would have a very difficult time getting it to fit in
the carrier.  The uneven halves of the carrier do not let our precisely
machined bushings line up so the pin could pass through.  That's why we now
machine them to exactly .393".  Occassionally we have to custom-modify a set
of bushings because of a greater variance in the carrier casting.

Previously, and apparently these are the sets you are measuring, we were
deliberately machining them larger to make installation easier.  We have
since gone back to the .393" ID as we originally had and allow those people
with dramatically uneven carrier halves to file out the bushing if the
variance of the carrier is so great as to not allow assembly.  The pictures
on your web site are not representative of current production parts.

Even with these tolerances, everything does stay much tighter than the
factory rubber bushing which allows up to 13 degrees of rotation in either
direction.   The machined UUC delrin bushings, even with this necessary
.001" allowance, still do an excellent job of preventing the carrier from
moving like the factory bushing.

I hope this clears things up.

Regards,
- - Rob Levinson
UUC Motorwerks * www.uucmotorwerks.com * 732-398-0001

- ----------------------------------------------
> From: RonStygar@domain.elided
> Subject: UUC Delrin front shifting arm "round" bushings: heads up
>
>   Although earlier noticed installing the UUC bushings on a short shift I
was
> doing, I assumed it was an outlier.  One of one.  We did not install them.
> As of today it is three of three.
>   If you choose to install the UUC Delrin bushings in the front of your
car's
> shifting arm, you may want to measure what you receive, before taking your
> car apart.  Their bushings are ~.010" out of spec. on the O.D. and I.D. on
> the round ones I have in hand.  They claim .001" at their web site.
>   Since there purpose is to eliminate slop and long term wear, installing
the
> UUC ones are worse than a worn out stock one.

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