Unusual shaking when accelerating
 

Hello,

I am the original owner for my 2004 Accord (110k miles) & started to feel a weird shaking/vibration with my car a few months ago. Here is the story:

1 - I put after market 19" wheels on my vehicle & only drove it one day with these. I then switched them back to my original 16" wheels BUT left the after market lug nuts on the tires without realizing it.

2 - I drove it with the after market lug nuts for about a week & I think they were also not the perfect fit

3 - I am now driving it with the original wheels & lug nuts but ever since feel that vibration.

Since then we've put brand new tires, balanced them, replaced the CV joints, aligned & rotated the tires.

We still have the weird vibration when we accelerate & when on the highway. Anyone know why this is happening?

There is no service or check engine light on or anything. Dealership & tire places don't find the problem either.

Any solution? Thanks!

could possibly be motor mounts, differential bearings or axles

Lug nuts are designed to mate with the wheels in all sorts of different ways. The most common two are: Tapered, mostly used with steel wheels to center the rims on the wheel studs (ie. Lug-centric wheels); and Flat, which are more commonly used with newer aluminum wheels. Some alloy wheels are Hub-centric, meaning the wheel is centered via a tight fit around the front hub, while others are like steel wheels and lug centric. They can also be both Lug, and Hub centric.

If the aftermarket lug nuts you installed on your factory wheels had a tapered end while the factory lugs were flat, it would have dug grooves into your rims where the lug nuts mate. (That is just one specific example, there are other ways it could have messed the wheels up.) Now becasuse of this, the wheels are not properly mated and centered on the hub, and it can be causing this vibration you speak of.

Inspect the rims, as well as the factory and aftermarket lug nuts and see if they are compatible. IF the aftermarket lugs did do something to your wheels causing the factory ones to not mate correctly, I would just re install the aftermarket ones and see if that helps. You should, though inspect the wheels for any potential cracks around the hub mating surface, because it is possible, though unlikely, that the wrong lugs could have damaged your wheels.

Hope this helps! Let us know how you make out.

would that make it shake only during acceleration though?

It can make it a lot worse, when accelerating. Since you put the wrong lugs on, are you sure your wheels are being held on to the hub tightly? If your wheels are loose, you will definitely get more vibration during acceleration. I think you have screwed up studs, or lugs, or wheels, or some combination of the three.

Hondas use hub-centric wheels, and the factory wheels use spherical-seat nuts.

Even if the aftermarket lug nuts have conical seats, the stock wheels would have been centered by the hubs. Conical-seat nuts would have probably been easier to work loose with time, so were they loose when you went back to check?

Remove the wheels & inspect around the seats for the lug nuts. Are they damaged? It would be either at the very center or the outer edge of the seat. How did the factory nuts go on when you noticed & swapped them back?

ps...
PC96, the vast majority of steel wheels use spherical-seat nuts. Honda factory alloy wheels also use them. Conical seats are common for aftermarket wheels, but flat seats seem to be uncommon in wheels for imported cars.

Jim, thanks for the correction, I wasn't really 100% sure on which type Honda's used (never thought to look all the times I had my own apart), most of what I said was hypothetical anyway. The flat nuts I was refering to though I have seen on most newer Toyota's. Link. The part of the rim that contacts the lug nut is completely flat on those wheels. But it could be called something different, though.

https://www.tirerack.com/images/wheels/tech/lug_nut.jpg
OK on the Toyotas - I haven't owned one. I've seen flat nuts on aftermarket wheels for older American cars, but really an aftermarket wheel company might use any of these types.