High Speed 4WD Front End Groan

[4boer2]

As the title states, my car has developed a repeatable groan. It’s only noticeable at highway speeds (I’ll say 70 and above) and it only happens when I’m in 4x4. Turns don’t seem to matter and it sounds and feels like it’s coming from the passenger side, though that could be because the front diff is to the right of the driver’s seat. Now here’s the funny part: it only happens at a very specific throttle point. If I’m coasting (no feet on anything), nothing happens. If I’m on the gas and accelerating, everything is also fine. However if I’m lightly on the gas but not enough to maintain the current speed, then it will happen without fail. The best example I can think of is gradually slowing down for a slower speed limit.

A search has revealed TSB0026-15, but that does not apply to me because this is only in 4wd, not the other way around. All of the search results are about this.

Any guesses?

 

[av8ter]

As the title states, my car has developed a repeatable groan. It’s only noticeable at highway speeds (I’ll say 70 and above) and it only happens when I’m in 4x4. Turns don’t seem to matter and it sounds and feels like it’s coming from the passenger side, though that could be because the front diff is to the right of the driver’s seat. Now here’s the funny part: it only happens at a very specific throttle point. If I’m coasting (no feet on anything), nothing happens. If I’m on the gas and accelerating, everything is also fine. However if I’m lightly on the gas but not enough to maintain the current speed, then it will happen without fail. The best example I can think of is gradually slowing down for a slower speed limit.

A search has revealed TSB0026-15, but that does not apply to me because this is only in 4wd, not the other way around. All of the search results are about this.

Any guesses?

Maybe don't worry about noises at 70mph while you're in 4WD on the HIGHWAY.

Reference T-SB "Owner's Manual"

 

[obxbum01]

I have a 2017 SR5 and if I recall correctly the manual said not to use 4 wheel drive above 62 mph .....

 

[wfo9]

There should not be a speed limit to 4wd, but there is a limit to when you can shift in and out.... Think it is 50mph...

However, I do have to wonder why someone would feel the need to be in 4wd at 70mph on a regular basis in a part time system on the road...

Not saying it can't be done.. just don't understand the need at all. A part time system creates more problems than solves at those speeds.

The noise could still be the needle bearings, but hard to say for sure. I would start with greasing and checking your U-joints.

 

[4boer2]

I had a feeling I would get critiqued. Like wfo9 said, I knew there was a speed limit for engaging the system, but I didn't ever read in the owners manual that there was a speed limit for being in 4wd. I am very willing to believe I'm going too fast, and if that truly is the problem then so be it. However this didn't use to happen and I haven't changed my driving style (being first to the mountain, I70 sucks).

I'll grab a grease gun and hit the u joints, I only do that about three times a year anyway..

 

[catrains]

doing 70 MPH and your need for 4WD is a bit weird..

what could be the cause is the tires are not all worn the same amount . I would measure all the tire treads..

greasing the U joints and the yokes could be but this type issue is at slow speeds .

could be bearings wheel or drive train. check all of those fluids .