Hi folks, I have a 2012 T&C. Over the past year or so I have had very intermittent (like once every couple of months) heavy vibration while on long drives at freeway speeds. I'll be just driving along with good road conditions, and suddenly it feels like I'm driving on a rumble strip.

It's severe enough that I either pull over or exit the freeway. I feel the vibration in the brake pedal as I'm slowing down. Vibration always feels like it's on the right side of the vehicle Usually after stopping I get out to take a look, don't see anything, get back in, and everything is fine.

It's been so infrequent that I haven't done anything, but this past weekend it happened twice. I'm thinking of replacing the RH halfshaft, but visually it looks fine, no grease leaking out of a broken boot or anything.

Any ideas? Thanks!

 

Have you checked your brakes for any unusual heating that can be felt by placing your hand near the center of the rim on any of the 4 wheels? Could have a dragging caliper or a situation with the hydraulic brake/ABS system.

 

No, I'll try that. But it doesn't seem like brakes to me, since the vibration starts literally out of nowhere, when I'm not even touching the brakes.

 

Now I'm wondering if I may have a transmission issue. I found a video suggesting that the oil dipstick can be used to check transmission fluid level. Using this method my fluid level is extremely low. Like 10mm on the dipstick when it should be 40mm. What do you guys think?

 

How are you checking fluid level? the motor should be running and in park on level ground. Sounds like time to do some visual inspecting of your ride for signs of leakage on the trans. to find out where the fluid has gone.

 

Yes, warm and running and in park. I think at this point I'm going to hold off on the halfshaft, get some ATF4+ into it, and see what happens and start looking for a leak. It could be a very small leak, though. This has been going on a long time.

Now that I'm thinking about it, I've been getting a clunk when shifting once in a while too. Didn't seem to be a big deal so I haven't worried about it.

 

The 40mm number if for when the transmission temperature is 180°F which I would consider hot, not warm. The fluid level varies greatly depending on temperature, the level would be 10mm at 70°F. You really need to check the level based on fluid temperature as shown in the chart below.