Grinding sound in 4low

I've got a 2021 TRD OR manual, about 20% of the time when I go into 4low I get a loud grinding sound from the front of the vehicle. Once it popped out of 4low during the sound and the second time it stayed in 4low, the sound quickly went away and I managed over obstacle just fine. Also, once I got stuck in 4low for about 5 mins... that was odd.

I've got 4000 miles on it and done a fair amount of off-roading so far. My previous vehicle was a 02 Wrangler Sahara manual, so maybe it's just user error something I just don't know about the Tacomas. This is likely useful info - I go into 4low by stopping the vehicle, shifting into 4h allowing it to engage then dropping the clutch while in neutral and toggling over into 4low. Once I shift into first and begin moving is when the sound occasionally occurs.

Side question: I also get a fair amount of clunk shifting into 4th, 5th, 6th and sometimes off the gas pedal at freeway speeds. On the shifting if I feather the clutch on those shifts I don't get the clunkiness as much or as often.

Appreciate any insight mechanical or user error

 

Should be stopped .neutral and then switch to 4low wait till the lights go solid . Then move forward slowly and you are straight not turned . Mine shifts into 4low like butter no noise . The shifting on the highway noise . It takes practice to get a smooth shift without clunk .most of the time I can get it to shift smooth without noise . I find shifting at higher rpm helps .

 

Getting into, and out of 4lo can be challenging with any 4X4. To get into 4lo you need to be either at a dead stop, or moving well under 5 mph. I actually find that it engages better at very slow speeds. With an automatic the transmission MUST be in neutral. With a manual either neutral, or with the clutch pedal all the way to the floor.

If at a dead stop you have about 50/50 odds that the gears will be aligned to make the shift. If you're rolling slowly the transfer case will shift to low range when the gears align as they turn slowly. With my automatic I prefer to stop on an incline to make the shift. If it doesn't shift right away letting off on the brake to let the truck roll a bit works. It only takes about 1/4 wheel rotation. It sounds like that you're not fully engaged in gear at times.

Getting out of lo range can be a PITA with any vehicle. Especially if you've been in lo for a while and pulling hard. The gears bind up and don't want to release. Driving a few feet in reverse usually does the trick. But I've had to do the back up 15-20', and pull forward 15-20' dance 3-4 times in the past to get out of lo range.

This isn't just a Tacoma issue. I've been doing this since the 1970's and every 4X4 I've owned has done the same.

 

It's not shifting into 4LO unless the clutch is FULLY depressed. You are initiating the 4LO shift with the clutch out so the shift is "waiting". Then when you push the clutch, shift to first, and take off, the truck is in the process of shifting into 4LO. You are now grinding the low range sleeve. When you hear grinding like that you've done something bad and something is wrong. Stop and fix. With the clutch all the way in at a stop, wait for the 4LO shift to complete which is communicated to you by a SOLID 4LO light and NO beeping.

 

Going into 4low is like butter on mine also, but you need to be perfectly stopped. You wouldn't know its engaged except for the dash lighting. Same with 4wd that can done on the fly. I couldn't get over how smooth, and silent it goes in compared to how my gen1 tundra did.

 

Appreciate the advice, Ive been fully stopped so maybe a bit of rolling next time.

 

Mm I've had it fully depressed and ive got stock floor mats but I'll be extra mindful next time. Appreciate the advice!

 

Yeah Ive found higher rpms is helpful, 1-3 is always smooth just odd 4-6 can be a tad clunkly.