BMR Tech Tip: Check those axle-to-spindle retaining nuts!

TNcoupe said:

[MENTION=18561]bandit67[/MENTION] CCPZ-3B477-F is the hub nut part number

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Thanks to this thread the popping and clicking at low speeds is resolved.
At 120lbs I got a good 2 full turns, at 150lbs I got another 1.5 turns. My issue was popping at low speed take off, and a clicking noise on low speed deceleration. Noticeable mainly when in gear. MT tranny. I thought it might be the metal diff lock out, the ring and pinion backlash, or even my upgraded vertical links. Turns out the nuts just were not tight enough.

Dealer fixed this issue for me on 03-23-2017 by replacing both half shaft axle nuts

the noise is back now, as I predicted on post #2

Well of course it is, there's nothing to keep them from backing out.

moffetts said:

Well of course it is, there's nothing to keep them from backing out.

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IF the issue is the new axle nuts are backing off, even after being torqued to 150ft lbs, here's a thought...

When the E36 M3 debuted back in the mid 90's, a problem that became widely known while road racing or auto crossing was the oil pump nut would vibrate loose and cause engine damage. After multiple failures were being documented from track events and from daily drivers, it was found that over time (without knowing when), the nut would eventually work its way off the pump shaft resulting in engine damage.

The fix:
Folks who found out about the issue started doing preventive maintenance on all E36 M3's by removing the oil pump nut, carefully drilling through it, reinstalling the nut onto the shaft and then would safety wire tie the nut so that it could not vibrate loose OR back off the shaft again. Today, these are now mass produced and folks can purchase pre-drilled oil pump nuts.

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Has anyone attempted to drill through the S550 rear axle nut and try safety wire tying it?

I'm including a pic (courtesy of ECS Tuning) to show a provisioned E36 M3 oil pump nut for reference so it can be seen how the nut was drilled and also a pic showing how the safety wire tie off was used in the BMW M3 application.

Granted we're talking S550's and the axle nut is different from an oil pump nut, but safety wire tying might be possible.

So car is at the dealership, getting only the driver hub and half shaft replaced. Not sure how I feel about them only doing one side. They said it was the splines that are damaged from when the nut loosened up that is causing the noise. Guess we will see how long it lasts. I will try to take some pictures of the old parts when I pick it up.

Cobra Jet said:

IF the issue is the new axle nuts are backing off, even after being torqued to 150ft lbs, here's a thought...

When the E36 M3 debuted back in the mid 90's, a problem that became widely known while road racing or auto crossing was the oil pump nut would vibrate loose and cause engine damage. After multiple failures were being documented from track events and from daily drivers, it was found that over time (without knowing when), the nut would eventually work its way off the pump shaft resulting in engine damage.

The fix:
Folks who found out about the issue started doing preventive maintenance on all E36 M3's by removing the oil pump nut, carefully drilling through it, reinstalling the nut onto the shaft and then would safety wire tie the nut so that it could not vibrate loose OR back off the shaft again. Today, these are now mass produced and folks can purchase pre-drilled oil pump nuts.

--

Has anyone attempted to drill through the S550 rear axle nut and try safety wire tying it?

I'm including a pic (courtesy of ECS Tuning) to show a provisioned E36 M3 oil pump nut for reference so it can be seen how the nut was drilled and also a pic showing how the safety wire tie off was used in the BMW M3 application.

Granted we're talking S550's and the axle nut is different from an oil pump nut, but safety wire tying might be possible.

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Just a note! That is a left-hand thread. If you go to safety wire anything always make sure your safety wire pulls in the correct direction.

Its mostly just dirt and some surface rust, looks worse in a picture. When I looked at the parts in person they really dont "look bad". But there is that one funky spot on the splines. I am wondering if it was the bearing myself. Maybe when it loosens up there is not enough load on the bearing it causing it to bind? Hell I don't know, its purely speculation.

I'll take a look at these this winter when I switch wheels. I'm only at 7,700 miles

Am I mistaken or are all of these on PP cars?

whatsup62 said:

Am I mistaken or are all of these on PP cars?

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Good question. Mine is.

whatsup62 said:

Am I mistaken or are all of these on PP cars?

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Mine is also a PP car

cechk01 said:

Mine is also a PP car

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I've been looking at the info to the left under everyone's screen name and it appears all PP cars...hmmmm

Could just be that a larger percentage of PP owners work on, tinker with, or modify their cars, and are therefore noticing/checking for more issues?

bandit67 said:

Could just be that a larger percentage of PP owners work on, tinker with, or modify their cars, and are therefore noticing/checking for more issues?

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Not for this issue, it's loud and noticeable.

My base 6mt is fine.