Grinding sound from front while in gear

[HollyM]

1989 Honda Accord LX-i liftback with under 200k on the ODO.

On a recent trip I noticed a rhythmic grinding sound. Not even a sound, I felt it in the floor under my foot. As I kept driving it worsened over the next couple days:

It is rhythmic and speeds up as the car goes faster; No relation to engine RPMs.
It only happens while the car is in gear. If I'm flying along and pop it into neutral, it goes away. Comes back when in any gear.
It does not seem to change much whether the car is turning or not. Maybe a little, but I might be making it up.
I do not feel the grinding in the shifter or steering wheel. Just in the floor but can hear it's louder now, too.

I drained the transmission expecting I might see metal flakes come out, but fluid was more or less clean. I don't think it's wheel bearings because that noise would happen regardless of whether or not I was in gear, right? Is it the CV joints? Is there a way to tell without replacing them and trying to drive? I did some searching through these forums and saw some posts that were similar to my issue, but not identical...

[Dr_Snooz]

Probably not CV axles, because those click when you turn corners. It's possible it's a mainshaft bearing or diff bearing, but I would think you'd be having other trans issues as well. At this time, I'd be leaning toward wheel bearings or possibly old tires. Give it more time and they might start making noise all the time. You can always lift the tires and check for play to rule out bearings.

[HollyM]

Probably not CV axles, because those click when you turn corners. It's possible it's a mainshaft bearing or diff bearing, but I would think you'd be having other trans issues as well. At this time, I'd be leaning toward wheel bearings or possibly old tires. Give it more time and they might start making noise all the time. You can always lift the tires and check for play to rule out bearings.

It didn't seem like it'd be the CVs... But would the wheel bearing make sense if it only did it while in gear?

[Oldblueaccord]

It didn't seem like it'd be the CVs... But would the wheel bearing make sense if it only did it while in gear?

usually the wheel bearings will be a high pitch squeal at first.

Is the big nut on the wheel hub tight? this preloads the wheel bearing. If its loose the bearings shot and might make some slop in the drive trains. It should have a cotter key to hold it in place.

The other thing is the clutch itself might be making some noise on its way out.

[HollyM]

usually the wheel bearings will be a high pitch squeal at first.

Is the big nut on the wheel hub tight? this preloads the wheel bearing. If its loose the bearings shot and might make some slop in the drive trains. It should have a cotter key to hold it in place.

The other thing is the clutch itself might be making some noise on its way out.

The Wheel hubs are tight and the wheels spin just fine. I can't feel any play rotationally or side-to-side. Also, no squealing. Just rhythmic grinding that has steadily gotten worse while in gear.

It's starting to seem more like something on the drive-side of the transmission... I just don't know much about this kind of transmission/differential setup.

[Shane86]

Does the noise sound like a sanding noise ? When was the last time the clutch/ throw out bearing was replaced

[HollyM]

Does the noise sound like a sanding noise ? When was the last time the clutch/ throw out bearing was replaced

Kinda. I'm not sure when either of those were replaced. But if it were either of those things, wouldn't the sound happen in conjunction with engine RPMs? The sound so far has only been speed related, and when in gear.

[Shane86]

Will the sound go away if you just push the clutch inn ?

[HollyM]

Will the sound go away if you just push the clutch inn ?

Yeah. Or if it's in neutral.

[Shane86]

Yeah. Or if it's in neutral.

Sounds like you might need a new clutch kit and flywheel soon

[2oodoor]

Just for shitz n giggles check the crank pulley bolt is not loose or missing completley, it does seem like a part that has too much run out under torque load, I would say trans input shaft/bearing as well, there wouldn't be shavings necessarily but yeah maybe some tiny shiny bits in the fluid.
Also could be something that is makng contact as the motor moves under load, like sloppy motor mounts and a power steering hose contacting the unibody and transfering an otherwise silent radial vibration from the engine or accesories.

[Dr_Snooz]

My first car was a '76 Accord. When I got it, I noticed a feeling exactly as you describe in the floorboard. It wasn't really a sound, but a feeling of roughness that clearly wasn't road related. I took it to the shop and asked them to check the wheel bearings, because I was sure one was going bad. The shop returned the car, telling me everything was fine. I had never really worked on any cars at that point, so I assumed the shop was right and ignored the feeling for the next few years. The feeling never went away, never changed and never became audible. Nevertheless, as I did more wrenching on the car, I became convinced that the wheel bearing was going bad. Finally, after bombing down a steep, windy and very long mountain road, I realized that it was a hazard and needed to be addressed. When I opened the bearing up, it was so far gone that it fell apart on the driveway.

Your noise isn't exactly like mine (mine didn't go away when I pressed the clutch), but I wouldn't rule out a wheel bearing. In your case, I'd say wait until you get some corroborating symptoms (like noticeable wheel runout, shavings in your waste oil, etc.) before spending a lot of money and effort to fix it. Of course, it's possible you may never get any additional symptoms beyond a gut feeling about what's going wrong.

[HollyM]

Ok thanks guys. I am going to investigate the wheel bearings first then. Hoping it ends there.
Will update my findings.

[Oldblueaccord]

Also when you refilled the trans you did fill it till it dribble out the fill plug. Thats the upper one. Most of us use the Honda manual trans fluid or motor oil.

[HollyM]

Started tearing away at the front end yesterday and found that the wheel bearings are fine, but the passenger-side CV joint was pretty messed up on the differential side, which explains why grinding noise didn't change much when turning. Took apart the driver-side too and found the CV joint was starting to go on the wheel side!

Ordering new CV joints today as well as a front suspension kit to replace the ball joints and bushings. Might as well since I've got everything taken apart, right?

Hopefully that'll solve the problem. Will update after new parts installed.

[Dr_Snooz]

Far out. Usually those clatter like crazy going around corners. Good sleuthing!