What air pressure in tires?
What size and type.
Sounds like a tire flat spotting when cold. Goes way as it warms up


Sent from my iPhone using Tapatalk Pro

 

What air pressure in tires?
What size and type.
Sounds like a tire flat spotting when cold. Goes way as it warms up


Sent from my iPhone using Tapatalk Pro

That's EXACTLY what it sounds and feels like, but pressure is good. I'm running 33" BFG ATs on the stock TRD wheels. Tires have maybe 15k miles on them- no noticeable treadwear at all.

 

mine (tires) do that all the time, especially if the truck sits over the weekend. cold weather it's the worst.

 

This sounds exactly like some version of flat-spotting or temporary tire distortion that gets corrected after the first few dozen tire revolutions, or the first few degrees of tire temperature increase.

Questions:
1. Does this occur EVERY time the vehicle is started, or only after sitting overnight?
2. Are you absolutely certain that you have isolated the thumping to the left-rear tire, or could there be multiple tires involved?
3. Is the vehicle parked indoors, or outside?
4. Has there been any recent change in weather conditions (reduction of night-time temperatures)?
5. What type of surface has the vehicle parked on when the thumping is noticed?
4. Are there any irregularities on the surface that the vehicle is parked on (potholes, gaps, seams or steps in concrete, etc.) that could deform the contact area on one or more tires?

 

Thanks very much for the reply! Answers inline below

This sounds exactly like some version of flat-spotting or temporary tire distortion that gets corrected after the first few dozen tire revolutions, or the first few degrees of tire temperature increase.

Questions:
1. Does this occur EVERY time the vehicle is started, or only after sitting overnight?
Seems to be only after it sits a while. Happens when I leave the house in the morning and when I drive home from work
2. Are you absolutely certain that you have isolated the thumping to the left-rear tire, or could there be multiple tires involved?
Not absolutely certain. Definitely coming from rear. When I stick my head out the window, sounds like left rear.
3. Is the vehicle parked indoors, or outside?
Outdoors at night sometimes on dirt, sometimes on driveway. During the day, open parking garage
4. Has there been any recent change in weather conditions (reduction of night-time temperatures)?
Some, but not drastic.
5. What type of surface has the vehicle parked on when the thumping is noticed
See above
4. Are there any irregularities on the surface that the vehicle is parked on (potholes, gaps, seams or steps in concrete, etc.) that could deform the contact area on one or more tires?
Sometimes, but it seems to happen the same whether I park on dirt or perfectly smooth concrete

One thing I should clarify. I feel the thumping, but sound is more of a ping- definitely sounds like there’s metal involved. Feels and sounds like someone is sticking a metal pry bar into the rim while it’s moving.
Thanks again for the help!

 

Have you swapped the tires rear to front to see if the thump "moves"