Whuuuring sound

Euston · May 15, 2021

Hey all, I recently added 1.5inch Bora spacers to my stock suspension (leveling kit), stock 20" wheels and now I have a Whuuring/Humming sound now whenever I accelerate. It's a constant hum as my foot is on the accelerator, even when I'm just cruising. When I take my foot off the gas it stops so that rules out hubs or anything to do with the wheel assembly, right? It has to be powertrain related.. Any ideas?

Thanks

CamGTP · May 15, 2021

If it still does it with the spacers removed then it's driveline related.

Likely the rear diff making the noise from bad bearings on the pinion.

MikeBMW · May 15, 2021

1 hour ago, CamGTP said:

If it still does it with the spacers removed then it's driveline related.

Likely the rear diff making the noise from bad bearings on the pinion.

Also, wheel spacers are always a bad idea.
If you need the stance, get rims with the stance you want.
I cannot imagine stressing wheel nuts (bolts) on a spacer.
Bad idea.
Maybe Bora does it differently, but, for myself, I'd never use spacers.
Not on my truck or my BMW.

Edited May 15, 2021 by MikeBMW

JimCost2014 · May 15, 2021

Now I am confused (well always), thought the spacers were suspension related, not for the wheels.

Maybe the drive line is now at an angle that is too far from factory specs? Maybe get out the protractor and see where the "new' angle is at, may need some shims to bring it back to a happy spot.

MikeBMW · May 16, 2021

4 hours ago, JimCost2014 said:

Now I am confused (well always), thought the spacers were suspension related, not for the wheels.

Maybe the drive line is now at an angle that is too far from factory specs? Maybe get out the protractor and see where the "new' angle is at, may need some shims to bring it back to a happy spot.

Sorry, Jim, the OP mentioned Bora spacers so I did a quick search and came up with this:
https://www.motorsport-tech.com/bora.html

JimCost2014 · May 16, 2021

2 hours ago, MikeBMW said:

Sorry, Jim, the OP mentioned Bora spacers so I did a quick search and came up with this:
https://www.motorsport-tech.com/bora.html

Good eye

Now I see how you are able to survive with 4 large cats of prey in your house

dieselfan1 · May 16, 2021

I doubt the noise is from the spacers.

As far as running spacers, a lot of misinformation is spread here.

First off ebay $50 spacers are junk. These are the ones that give spacers a bad name.

Bora are quality but they are aluminum.

I'm running 1" Stahl steel spacers on the rear of my lifted truck to even out the stance with the front. The lugs and nuts on these are higher quality than stock. 10.9 grade.

See if you can find any failures on these. You cant.

Euston · May 16, 2021

So I removed the spacers on the rear wheels and the sound went away. very happy it's not drivetrain related.

The Bora spacers come with nuts, so you use their nuts on your studs for the spacer and then your wheel nuts on their studs for the wheels. I agree with you, that it'll be way better to just get some better offset wheels and do without the spacers.

Thanks guys.