2012 Tacoma 6 speed grind when shifting on bumpy logging roads

I have a 2012 Toyota Tacoma Double Cab TRD Sport V6 with the 6 speed manual transmission. Over the past month, I've taken it on a couple camping trips which involved going on logging roads. I noticed on bumpy sections on these logging roads (sections with constant pot holes one after the other, washboard, etc) that sometimes shifting gears (usually downshifting from 3rd to 2nd at about 30kph) would result in a bit of a grind from the transmission, and I could feel it a bit in the shifter as well. This didn't happen every time, but it happened enough times to make me concerned. I realize this is not a great transmission, I test drove 3 different trucks with the 6 speed before I bought this one and felt that none of them shifted as well as my old '94 4runner with the 5 speed did. From the research I did, I found that most people felt the transmission was tolerable if shifted with the right technique and using Redline MT-90 oil, so I decided to give it a shot and bought the truck. I switched the transmission fluid over to the Redline a few weeks after I bought the truck when it had 1500km on it (it has 5000km on it now) and did notice a slight improvement but still find the shifts a little rough sometimes when upshifting from 1st to 2nd and from 2nd to 3rd and downshifting from 3rd to 2nd and from 2nd to 1st (though I try to avoid downshifting to 1st whenever the vehicle is moving since it doesn't seem to like it at all). However, I have never gotten a grind from the transmission on smooth paved roads, even when the factory oil was in there, it's only happened on bumpy sections of the logging roads. Has anyone else experienced this with their 6 speed? Should I be concerned here, or is this just the way these transmissions are? My old '94 4runner sure never did this, I know that, I could shift that truck any time any where with no problems.

 

Mine grinds gears shifting over bumps too. I think it's just par for the course. My '04 did the same also.

 

same here, it's minor grinding... figured it was due to trying to shift too soon but could just be how it is set up

 

i got a 12 dcsb trd six speed never shifts 1 2 3 like it should 4 is smooth 5 and six but for some reason it resists second and third a bit ....hope the truck will be ok.....i havent read any post with anyone having significant miles on thier new trucks yet i got 100000 miles bumper to bumper....when i grab 1 2 3 over bumps i dont get a grind its kind of a chatter theres only 1200 miles on my truck what do you guys think

 

I do 2 way transmitter work on mt tops part time and often use 4 low going up the mt's and yes it wants to crunch some times going over water run off's but my old 97 with a 5 spd did also.