'03 Tranny slip/Exhaust resonance

[TetTundra]

2003 4x4 SR5: Have an annoying transmission slip and/or quick downshift, then upshift when going around street corners and over speed bumps. Both actions are about the same; going about 15 mph, decelerating and braking, then touch the pedal and there's a quick engine rev. Bugs the hell outta me. Any ideas? Auto tranny isn't the "silky smooth" one I read all about.

Also have a resonance at 1800-2000 rpms. Seems like exhaust, and more sound driven than mechanical. Believe it on not, all weather floor mats dampened the effect thru the floor board, but still noticeable. The truck actually has more exhaust noise than I'd like.

Ordered the truck - now with 758 miles.

[acme]

My 03' does the same thing, but it's just the engine speed catching up to the speed of the drive train. When you left off then get back on it will do it. It's the, "drive by wire" ,throttle opening quicker than your normal cable /spring loaded throttle .(no throttle cable)... Since the engine is not under a load the throttle will snap open and cause the engine to rev quick and cause the "slip" feeling. I mastered it by easing down on the throttle a little slower and that feeling went away. The resonance went away when i put a rubber "Bed Mat" in the bed in back....I don't have a bed liner just the rubber mat that fits all corners..... Alan

[TetTundra]

Acme, thanks for the reply. I also put in a rubber bed mat, but it didn't help all that much. Regarding resonance though, I was under the truck this weekend and see that there is a very light weight heat shield under the driver's seat above the exhaust. It is screwed to the floor pan and has a couple of loose extensions. If I just twang these a little bit by hand, it's like a tuning fork! I'm thinking that's the source of the vibration-resonsance at 1800-2000 rpm. Will do some testing. Seems like a "not-so-good" design.

[acme]

You can put another spring on the gas petal linkage under the dash to keep from mashing it too hard also.
I did this to a new car i bought years ago and it was easier to drive. A cheap NAPA carb linkage spring will do with low tension...
Now, on my Tundra i give it little gas when starting back up off a slow turn or a Stop/Yield sign , i don't need it.. just a thought...

Alan

[S-Man]

hey tet, my '02 used to do that too. When i would turn a corner, then lightly get on the pedal to accelerate out of the corner, it would downshift to like first, and snap your neck like a rag doll if you were'nt ready for it. I dont notice it anymore, either it has gone away due to break-in, or i've gotten used to the pedal feel, so i now know how to modulate it, i dunno.
As far as the resonance gos, i dunno about that, but on mine, when i'm in park or neutral, and i rev it up, like stab the gas, then quickly remove my foot, theres a rattle-vibration sound as its decellerating. Its not very noticable, but it kinda bugs me.