07 Tahoe - occasional Bucking feel when in AWD in Snow

[okfoz]

2007 Tahoe LTZ 5.3L 4WD, 233,000 miles (4 Speed Trans)
Here are the conditions
1) Snowing, Does not matter how deep, or how much, just must be at least a little slippery.
2) Traveling at a constant speed, IE Expressway.
3) Truck is in "Auto" or 4WD
4) Speed seems to always be between 45mph and 65mph
5) Will only do it once every 5 to 10 miles if at all.

Occasionally under these conditions I get what can only be described like a jerk or buck, and there is an audable bang, like it gets traction. It feels like the a slipping transmission, but it is very quick, and it only happens when traveling at a constant speed. It seems to do it more often when in "Auto" than 4WD, but it has done it while in both. I thought it had something to do with the 4WD engaging (like the transfer case encoder or front axle engagement) when feeling a slip, but it will still do it under 4WD when all of that should be engaged.

There does not seems to be any revving of the engine, if there is I do not perceive it.

If in "Auto" on dry or simply wet pavement I do not have the issue.

Anyone else had this issue that might point me in the right direction?

Thanks

 

[Geotrash]

Are all 4 of your tires identical?

 

[swathdiver]

Are all 4 of your tires identical?

My first thought too! Did you check the tread depth of all the tires and make sure they are all within a pound or so of pressure? All the same brand? What it comes down to is circumference, they all ought to be within a quarter inch or so of each other if memory serves.

 

[Doubeleive]

could maybe be a ABS sensor giving a erratic or lazy reading
at 233k I would imagine you have already done the front hubs?, if not that's one of the 1st things I would check
if you have a scanner that can read live data, then put in on abs sensors and monitor live data while driving, the erratic one will be your culprit.

 

[exp500]

Have the front driveshaft splines been lubed since you got it?

 

[Doubeleive]

Have the front driveshaft splines been lubed since you got it?

???

 

[Fless]

Long shot, but check the action and speed of your front diff actuator, they can get lazy and I would also think intermittent. That would cause the front diff to engage and disengage at the wrong times. You can unscrew it and let it hang down, and select the dash switch from 2HI to 4HI to watch it move. Should take only a second or so.

Also check and clean the ground connection on the frame rail, right behind the left front tire.

 

[okfoz]

Brand New Michelin M/S Tires, only have 6000 miles on them if that. It started doing this with the old Bridgestone Dueler Tires a few years back...

Are all 4 of your tires identical?

 

[Bill 1960]

Have you owned this a long time, and is this a recent condition?

I‘ll hazard a guess it’s encountering some tire slipping (because it doesn’t happen in the rain or dry) and it’s related to the sudden transfer of torque. Check the front differential mounts and transmission mount. Could be a problem in the front diff engaging motor or shift fork.

 

[okfoz]

I have owned it since 2014 when it had 70,000 miles on it. It is more recent, the first time I noticed it was around 2019, it has not gotten worse, or better, it is just random. That is what it feels like, something is slipping then it engages causing the thud sound and the jerk.
What is probably the most peculiar is there is no rhyme or reason for it, it will do it going down hill, up hill or on the flat. I am always traveling at a constant speed when it has always happened. If I accelerate I have never noticed it. I can never seem to force it or trick it into the thud, it just happens...