Resjudicata

My wife has an '04 accord LX with the 4 cylinder automatic with 60k miles. The car developed a shudder on acceleration. You can't feel it through the steering wheel. It feels like it is coming from the center of the car. It is only on acceleration, the frequency is matched to road speed rather than rpm and it gets stronger the more gas you give it. The shudder happens at all speeds but only when accelerating. No shudder on coasting or just light throttle to maintain speed, only while accelerating.

The ball joints, tie rods and everything else in the suspension look good. I've jacked up the front and tried rocking the wheels side to side and top to bottom and get no movement likely with bad ball joints or bad wheel bearings. I've rotated tires and the shudder did not change. I replaced the passenger side half shaft because I am at my wit's end and that didn't help or change the issue. The engine idles smooth as silk. The car isn't losing power or cutting out while accelerating or at any other time. The transmission isn't slipping. The car accelerates as well as it ever has, tracks straight and does everything else perfect. It just shudders when accelerating.

Anybody have any ideas?

Thanks,
Chris

bradybunch2101

I have had this problem on some other vehicles, and it always led back to the transmission. The tranny doesn't have to be slipping for there to be something noticeably wrong with it. Try putting the transmission into the lowest gear and accelerating up to about 5K RPM. Do this a few times then move transmission up to 2nd gear and go from about 5mph to 15mph without redlining the tachometer. This procedure may help you identify the gear in which you are having the most problems. You can go through the rest of the gears in the same manner.

BLKFLSH

Have you checked the engine and tranny mounts?

Resjudicata

I have. It does it in all the gears and is dependent on road speed, not rpm or gear.

Thanks,
Chris

Resjudicata

Yep, all the engine and transmission mounts are solid. Also, no vibration at all from the engine. It sits as smooth as if it were new whether it's idling or in gear.

Thanks,
Chris

Resjudicata

It was the driver side half shaft. I swapped it out as there was nothing else that was a likely culprit. That fixed it. I also found a post on another forum from '08 that asked about the same exact problem. The guy took his to the dealer and the dealer told him that they were getting a bunch of the '04 Accords in with bad driver side shafts at about the same mileage.

Thanks,
Chris