Is it worn-out tranny/engine mount issue?
(1997 4Runner SR5 with Auto tranny at 140k miles)

I believe it is no serious immediate issues but just plain old 12 years old car symptom with auto tranny.

No issue and no symptom during normal driving, only somewhat sluggish/slow shifting in cold weather but nothing unbearable.
No burning tranny oil, no slipping, it feels actually quite ok considering its age and miles (97 4R, SR5 with Auto tranny at 140k miles).

But, when I tried that old trick of checking tranny and/or engine mount (shifting tranny level while firmly holding brake pedal to check if any clunking or vibrating), I was able to sense quite increased "clunking".

Now, my questions are,

1. Is it sure sign of tranny and/or engine mount? or else?
2. Is it relatively easy common area to tackle for home-garage mechanic like myself?
3. If I don't fix it immediately, what is long term effect? (a little more accelerated wear on clutch etc?)

Thank you in advance.

Regards,

 

Could be U-joints?

 

put the runner on level ground, in park, with the hood up. Stand in front of it and push it back and forth(the little bit of freeplay in the "PARK" gear) If you see the engine moving back and forth while doing this, its time for motor mounts.