Magnum axle warning

[enjenjo]

You might find this of interest. There is a ton of useful info on the LVVTA site.

http://www.nz-hotrod.com/vbulletin/showthread.php?8165-‘Magnum’-brand-I-beam-Axle-Safety-Warning&p=102618#post102618

http://www.lvvta.org.nz/documents/infosheets/LVVTA_Info_06-2012_'Magnum'-brand_Axle_Safety_Warning.pdf

[Canuck]

Thanks for the post "engenjo".

As I have a Magnum axle the information on the web site helped to put my mind at rest, especially the information on dates that the bad batch was processed.  Mine is from 2004.

To bad Magnum are stamping inspected units at a location that might require removal of the wishbone/radius rod to verify.

Would be nice if items like this were stamped with a manufacturer name and serial number to ease tracking when problems occure.  Mind you maybe that is why the manufacturers don't mark them.

Thanks again for the link.

Canuck

[unklian]

This was a Magnum from Speedway.
The driver escaped with a broken leg.
http://www.tbucketeers.com/threads/parts-failure-does-occur.11069/



There are broken Magnum and Superbell axle threads on the HAMB.

[Digger]

Anyone know where these castings are coming from? local or somewhere across the pond :?:

[wayne petty]

this idea is kinda late...

but.. perhaps some of you already do this..   purchase a notebook/binder/scrapbook..  to save all your receipts in for each car..

i would think that any manufacturers are going to be doing destructive testing on one or two random samples from each batch of axles and other CAST parts from now on..

they might even include a card to be completed and mailed back to the company.. with the assigned VIN number for the build and info on ownership...  so they can contact you.. and they also have a record that you purchased an device from them to cover their pants seat...


there are so many places that can do axle forging now a days with all the medium duty trucks being produced..   its almost crazy to run a cast axle..

as for the tube axle that was decoratively welded..   i have a huge question..    how many people would run an axle that 80 percent is drilled through and welded to a different thickness and probably material..

sorry for spouting..   i am one of the people who have called SFI to ask about chrome moly axles and chassis..  they put me in touch with the guy who wrote the specs for that .. when i ask him about stress relieving the chassis or tube axle...  he said the use reverse polarity welding and it pulls the heat out of the weld .. so there is no thermal problem with welding chrome moly and not stress relieving it..

i actually went as for a finding several companies who can stick an ENTIRE 300 inch wheel base top fuel dragster chassis into their calibrated and fully instrumented heat treating oven...    that company rep only ask.. do you mind if its exposed to direct flame in some areas during the warming  as it would kinda fill their oven...

ran across a company who does chrome moly sprint car chassis all the time...   funny car chassis would fit in that vacuum thermal chamber  easily..

as for hydrogen embrittlement..  the part has to be baked at 900F for 24 hours just prior to chroming to remove any hydrogen from the metal..  and not allowed to sit  for much more than the time to cool as i under stand before it goes into the plating tanks...  this is what is done in aerospace chromed parts to avoid the issue...

again... sorry for the RANT..

i guess i am just brittle on this subject..

why does chrome moly need to be stress relieved..  it has extra carbon that needs to be baked out.. to achieve design strength...   if the stress relieving is not done properly and evenly.. the tubing or device will have hard brittle spots that are likely to crack and soft flexible spots that don't
the soft spots which are desirable.. are at the welds.. and a few inches out.. then it becomes carbon rich.. and brittle..  this is why it breaks.. away from the welds... so you don't think the weld is causing the problem
heating it with a rosebud is not the way to properly stress relieve it..  unless you have a wrap around shield like is available on propane torches or hot air guns.. to equalize...  there are welding tips that are for brazing fittings that have a question mark shape... and flame coming around a complete circle..  but these still are not doing it right...

[Digger]

A few years back, I sponsored a formula car (a British Lotus) complete birdcage chassis and all moly. I had decided to redo the chassis in Imron and when it came back from the sandblaster I found the entire thing was brazed from the factory. I guess they figured it took less heat and would bend not break.

[unklian]

Brazing was common on British sports cars.

While the temperature is lower, it takes
more heat, so the joints cool slower.

If Chromemoly cools too quickly, it gets brittle.

There is a procedure, of preheating the joint,
before TIG welding, to get around this problem.

[wayne petty]

an important 5 minute read on 4130...

http://www.netwelding.com/Heat_Treated_4130.htm







perhaps i am not crazy after all.

i still think I am. and me, myself and i all agree..