• Registered: 2020-02-02
  • Posts: 3

Topic: Rear Hub/Axle Collar nut failure on e36?!?!

Calling on all e36/e46 teams for advice.  We're ran at Lemons Barber Race this weekend - had a blast but had two identical failures, 1 that ended our Saturday run and 1 that ended Sunday.

Both Left and Right wheels broke off.  We believe hub failure but can't determine root cause necessarily because of the catastrophic failure and subsequent damage. 

Wondering if teams have experience hub failure or axle collar nut failure (we did visually inspect prior to race and the nuts on both sides were dimpled in. We had also installed the hubs as replacements, everything torqued correctly.  Newest one was about 3 years old.  Both have been through about 6-8 Lemons/Chump races.  Never had failures like this before.  Both lower control arms, trailing arms, half shafts had all been replaced so nothing "old and crusty" under there.

Any ideas?  Also open to suggestions on how to reinforce, strengthen, and any pre-race prep or checklist teams go through for their suspension as they prep their e36.

Thanks!
Tom Butler, Raleigh, NC
B&W Racing, 1994 BMW 325i Cat in the Hat Theme

  • From: South of Chicago
  • Registered: 2011-11-26
  • Posts: 750

Re: Rear Hub/Axle Collar nut failure on e36?!?!

More details needed.
How many races on the hubs before failure etc.

Are the bearings part of the hub?

I've seen issues with FWD bearings and hubs.
Fixes have included "over tightening" the hub nut.
Repacking the wheel bearings in the hub with HiPer grease in place of the stuff the vendor uses.
And just replacing them on a regular schedule, this avoids the chance of failure which you already know all to well.

Did the car see some hard "offs" during a race?
Do you bounce it off any curbing during a race?
Both can lead to early failure.

  • Registered: 2020-02-02
  • Posts: 3

Re: Rear Hub/Axle Collar nut failure on e36?!?!

I've cross-posted in champcar - got some good replies there as well.

No offs or hard gator crossings that would have caused this.


Here are answers to the questions and recommendations that have come out in thread.

  • Lug bolts are fine - you'll see they stayed intact on wheel as rotor fell apart.
    We're going to start a replacement of hubs after 5 races to be proactive.
    I like the idea of the paint stick across nut and dimple to see if it has moved or backed off.
    I can confirm we torqued to spec, 184ft lbs on both sides.
    Axles seemed fine and were new-ish, 3-4 races.  End of spines now slightly damaged due to hub failure.
    Good idea to check the three rear differential bushings hold the differential to the subframe. That might have caused some slop in the rear causing undue stress to the sides.

  • Registered: 2017-02-22
  • Posts: 221

Re: Rear Hub/Axle Collar nut failure on e36?!?!

I seem to remember that someone had this failure at NCM. Drivers rear.

Lowballers?

Was the car with the "wiring" outside of the body. Car was black (and green?)?

I think I have the pics on my old phone.

I'll look.

88 Festiva  -  Damn Tree!!!
"We Are Not Really From Iran" Festiva  -  Motor and Trans to be anounced
  • From: Birdsboro, PA
  • Registered: 2009-10-26
  • Posts: 892

Re: Rear Hub/Axle Collar nut failure on e36?!?!

I was driving that black BMW when the wheel fell off at NCM.  The axle end broke off, hub failed, rotor hat broke off, then the wheel with still bolted hub and rotor hat departed from the car.  Everything was replaced with new quality parts and the car did it again about 5 races later.   Never any contact, not habitual curb hoppers either.  Now those parts are replaced regularly.  Front hubs are also a wear item

Chris from 3 Pedal Mafia
  • From: Elverson, PA
  • Registered: 2017-08-15
  • Posts: 1,128

Re: Rear Hub/Axle Collar nut failure on e36?!?!

Mmmm, I want me some Ultimate Driving Machine® racecar...

  • Registered: 2020-02-02
  • Posts: 3

Re: Rear Hub/Axle Collar nut failure on e36?!?!

Effluent - crazy that this happened to you guys too!

We had not had this problem having run for last 7 years.  Had some damage to lower control arms that caused us to replace hubs but not as a wear item.

How often are you now replacing?  Every 3-4 endurance events?

Also - what parts are you using and where are you sourcing? 

Thanks,
Tom