HMMWV vibration and noise when braking.

[Kraz 255]

Hi, I have an M1123, I'm dealing with vibrations and especially noise when braking. The brake discs and pads are like new, everything moves freely. The more I brake, the louder the noise - there's a clicking sound. Does anyone know? 99% sure it's not the brake calipers and pads.
It sounds to me like the noise is coming from the final drives on the wheels. Or maybe it's like the front and rear cardan shafts are clicking against each other. It sounds like clearances are being defined. Thanks for the advice.

 

[MarkM]

CV boots okay? Is there oil in the portals? The hub nut for the axle tight? Are the bolts on the inner mounting flange of the axle tight? I would start with the above.

Mark

 

[Kraz 255]

Shaft seals are fine
Oil in portals is fine
All pins are free of play. All screws I found are tight.
I don't know what else to check. Everything I see is in good condition.

 

[Mogman]

Welcome to the SS forums!
The geared drives have straight cut gears and do make a certain amount of noise.
This is much more pronounced in vehicles with hard tops like the helmet top etc.
Is this your first Humvee?

 

[Kraz 255]

Yes, first one. I don't have a reference car. Maybe it's normal. At first glance I would say crooked brake discs. But the car should have 3000 miles and the appearance of the discs corresponds to that. They really look like new.

 

[Mogman]

The HMMWV is known for having brakes that chatter, likely because the brake discs are not mounted directly to a wheel and tire ass which would naturally damped the high frequency chatter, it is usually mostly common to the rear brakes.
One trick we used to do back in the 70s on our motorcycles that had just started using disc brakes which were bad about having chatter, we would coat the discs with pledge spray furniture wax, it would stop the chatter for a while and then would burn off but did not seem to affect the stopping power.