Excess road noise after body mount replacement

[BluIsBlue]

Hey y’all, as many of you know, I drive a 2001 2 door Explorer sport. The truck had some road noise, ride quality and some issues making it so the passenger door shuts improperly. I diagnosed it with bad body mount bushings (some of them I could put my finger through, some others simply weren’t even there anymore). Someone bought me new bushings as a gift so I can fix the issues I had. The problem is, they were sport trac bushings and only properly match up (I’m pretty sure) with positions 1, 2, and 3. By the time I got them, we couldn’t refund them. So I decided to just replace what I had. Now that I’ve replaced them, my passenger door aligns properly and closes like it’s brand new again and road imperfections are far less harsh inside the truck. But, the road noise has gotten a lot worse than it was before. Between like 10-45mph the noise is bearable but it’s at its worst between 50-75mph. Right around 80 and above it quiets up again. When going above 25ish mph and cornering to the left (when some body roll is introduced) the noise disappears entirely. However this does not happen when cornering to the right. This last symptom was the same with the worst of my road noise before replacing the bushings. When I’d be going around 35 and above and the interior was loud, I’d corner to the left and a lot of the noise would go away.

Does anyone know of anything that could be causing this excessive road noise? Has anyone experienced anything like this in the past? I don’t think it’s from the motor or its mounts because the noise doesn’t change with RPM, only with speed. As always, any and all help is appreciated!

 

[wollimann]

Wheel alignment, old tires, bad wheel hubs, bad front shafts
and of sure old hard body mounts.
Bought our 97 new and it was so quiet the first years.
Never changed the body/motor/transmission mounts, but today it's very loud inside
and every litte vibration gets you rapidly.
Every time with new tires i notice less noise.

 

[BKennedy]

Retorque body mounts?
What was the difference between Sport Trac and your model's mounts?
Were the replacements polyurethane or rubber?

 

[BluIsBlue]

Retorque body mounts?
What was the difference between Sport Trac and your model's mounts?
Were the replacements polyurethane or rubber?

Replacements were poly. The difference should only be that the trac has separate ones that replace my rear positions because it has the bed vs mine being the shorter 2 door. Everything from the very front to at least the drivers seat should be 1:1. I could try to retorque. But they’re damn tight. Maybe I over-torqued them?

 

[BluIsBlue]

Wheel alignment, old tires, bad wheel hubs, bad front shafts
and of sure old hard body mounts.
Bought our 97 new and it was so quiet the first years.
Never changed the body/motor/transmission mounts, but today it's very loud inside
and every litte vibration gets you rapidly.
Every time with new tires i notice less noise.

My problem is that it was general wear interior noise before replacing the mounts. After replacing them, the noise was far louder. Almost to the point where I feel I should just remove the bushings and go metal to metal as that was better. Alignment and tires should be okay. They aren’t that old and I’ve aligned it myself. However it’s been through some gnarly holes and such so maybe an alignment isn’t an awful idea. I’ll have to see about getting the hubs and shafts properly inspected… hoping those aren’t the problem because that will be a PITA. But it is what it is.

 

[BluIsBlue]

If it would help, I can try and record the noise and how it goes away when cornering to the left

 

[BKennedy]

It's possible they were overtorqued. I replaced the body mounts on my 1994 Explorer a few years ago. It made a big difference in flex, but I didn't notice any added road noise. It also has sound deadening material on the floor. My rig has been modified for off road so the tire noise overwhelms everything. They had a specific torque setting that I looked up off poly performance.

I would get the front suspension off the ground and service the wheel bearings. While it's up, get a tire iron or other long bar and check the ball joints, tie rods, anything with a bushing or joint for play. Then go to the rear and do the same, but check for frame cracks on the shock cross member and at the front leaf spring mount.

Lastly, get the bar under your engine and wiggle the motor mounts, then the transmission mount. You can also have someone you trust sit in the driver seat with a foot on the brake and give it a little gas while you watch to see if the engine moves more than a little, standing to the side of course.

Your issue is something that moves that's not supposed to move.

 

[BluIsBlue]

It's possible they were overtorqued. I replaced the body mounts on my 1994 Explorer a few years ago. It made a big difference in flex, but I didn't notice any added road noise. It also has sound deadening material on the floor. My rig has been modified for off road so the tire noise overwhelms everything. They had a specific torque setting that I looked up off poly performance.

I would get the front suspension off the ground and service the wheel bearings. While it's up, get a tire iron or other long bar and check the ball joints, tie rods, anything with a bushing or joint for play. Then go to the rear and do the same, but check for frame cracks on the shock cross member and at the front leaf spring mount.

Lastly, get the bar under your engine and wiggle the motor mounts, then the transmission mount. You can also have someone you trust sit in the driver seat with a foot on the brake and give it a little gas while you watch to see if the engine moves more than a little, standing to the side of course.

Your issue is something that moves that's not supposed to move.

Yeah the something moving that isn’t supposed to was what I figured. Chances are I need to do a front end refresh soon. When I did my brakes, I noted to myself that my front end suspension could use some new on it (namely ball joints) but there wasn’t enough while inspecting to warrant an immediate replacement. But I could’ve been wrong and the truck has seen some trails since then

 

[410Fortune]

We are thinking the noise has always been there
It is just now amplified through the body because it’s actually mounted to the frame now

I ran through over text how to do a quick shake down test
Suspect front driveline, cv axles and wheel hubs.
Front end needs a simple shake down test look for
Looseness in ball joints tie rod ends tires bearings and joints
Front driveline and front pinion bearing can make a nice loud roaring noise

Typically a noise that changes with a side
Load is a wheel bearing hub issue or loose tie rod allowing the tire to wobble

Jack and a pry bar
Find the noise, no guessing

 

[BluIsBlue]

Hey yall, I found out what it was in the end. Bad wheel bearing on my passenger side. Replaced the hub with a timken one. Everything sounds basically new again. There’s still some harshness from the lack of new body mounts towards the back of the vehicle but that’s a different issue entirely. The overwhelming noise is entirely gone and I do not dread driving the Explorer now haha