Drew,
No more swap meets either! I just got a post card anouncing one next month
(September) It says "Last one ever".
Gerard
At 1:27 PM -0700 8/30/00, Andrew.Griffith@ReadRite.com wrote:
>I'd like to share this explanation on the front bearing spacer and shims
>topic that we've been beating to death lately, it sounds logical. It's an
>answer to a question I sent to Mike (a Sprite racer who's not on the list
>and lives in South Carolina) and I don't know his last name.
>
>And BTW... I just talked to Don at Mini Mania, they don't sell the front
>wheel spacer shims. Don also told me that they are moving to Grass Valley.
>Drats!!... no more lunch time visits to MM.
>-Drew
>
>
>Drew,
>Yes, these spindles/stub axles have broken in the past. A fellow out on the
>west
>coast (British Masters) recounts a tale of a serious accident and long
>recovery
>time due to a broken stub axle. For the most part, the failures are due to
>stress fatigue for the materials used. Magnafluxing during the winter hiatus
>from racing is a good preventive maintenance. Another solution is to upgrade
>to
>the 4340 steel spindle that has been machined from an extrusion and is then
>pressed into the swivel portion of the stub axle and welded in place. The
>factory steel is of the EN17 variety which falls into the common variety
>3000
>series steels here in the US.
>
>I have run the BTA746 and BTA747 stub axles for many years using the
>assembly
>method outlined without a failure (knock on wood). In discussing this matter
>with one or our stress engineers here on site, our conclusion was the
>installation helps insure 1) the inner races won't turn, 2) ensure the
>bearing
>loads are consistent at known application points to the stub axle and 3)
>prevent
>any slop (loosness) in the installation for increasing the bending moments
>at
>the inner bearing root of the spindle.
>
>The installation won't make the stub axle any stronger, it only assures the
>loads are consistent due to a better installation.
>
>We probably could have spent an hour discussing the materials, the
>installation
>and all the various conditions, brought in a couple more engineers and still
>come up with about the same conclusion. Maybe tomorrow.
>
>I will e-mail you with the cost for shipping the parts on Friday. I have
>some
>time to go to the UPS shipper and get the information.
>
>Hope my discussions help.
>
>Mike,
>You had mentioned before that I should use the center wheel bearing spacer
>even though I've converted to the tapered roller bearings, but I'm having a
>hard time figuring out why.
>With the spacer in place, correctly shimmed and the caster nut torqued to 90
>Lbs., the end result would be an outward pulling on the axel and a
>compression force on the inner bearing races locking them on the axel with
>the spacer between them. I don't see how this would make the axel stronger
>or is the objective to keep the inner bearing races from turning on the
>axel? Do these cars have a history of axel problems when the wheel bearing
>spin on the axel creating a stress line for a future failure?
>Thanks,
>
>-Drew
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