Car Jerks When Not Accelerating

Question

So, I just recently mounted snow tires on my car (or rather, paid someone else to do it), and on my way home I noticed that whenever I take my foot off the gas pedal the car jerks forwards and backwards rather violently. This hasn't ever happened before, literally started the second I left the shop parking lot.

It stops when I disengage the clutch, which leads me to think it may be a symptom of a failing clutch. Also, as the guy was pulling my car into the garage I noticed he was revving the engine pretty high and seemed to be riding a little bit. What's weird though is that my clutch doesn't seem to slip at all during starting/acceleration. I'm not sure when the clutch was last replaced but I believe it was a while ago.

Could this be related to the tires at all, or is this definitely clutch? It's just a little strange that it hasn't happened at all until I switched tires.

Answer 1

I have had an extremely minor variant of this happening on all manual transmission cars I have driven when driving at slow speeds and the 1st gear was engaged. None of the times was it so severe that I would bother to get it fixed. The phenomenon got slightly worse with age.

I always have thought the cause was motor mounts. As the phenomenon occurred only at very slow speeds in 1st gear, I avoided it by slowing down not by engine braking but rather by using the main brake and clutch.

Almost certainly the phenomenon has nothing to do with your tires, unless some of the nuts / bolts is loose.