I have a 2025 trd off road and noticed even when on slippery roads when I shift to 4hi the engine feels like it's under a huge load, shaking and vibrating? Wondering if the gear ratio's between transfer case, front and rear diffs and transmission are slightly off? It's not my first 4X4?
Four bangers are not inherently balanced engines, so under load they are more likely to shake or vibrate. Maybe that is what you are feeling?
My 82 Toyota 4X4 4 banger was always smooth as silk. I've seen a lot of complaints of people having their auto transmissions overheating when in 4hi on 4th gen Tacoma's, something doesn't sound right?
I was just speaking from a mechanical engineering POV, that inline 4s are not naturally balanced engines. I have had more than one Toyota 4 cylinder that was very smooth too. I have not noticed any unusual vibration when my truck is in 4HI. It would be interesting to see if anyone else has noticed this.
I actually did a little experiment with this today on a trail, drove the entire thing in S1, since the trail was best at around 10mph.
I noticed this as well on my first time out with the truck. Leaving it in (D) 2Hi and 4Hi, it would shift into 3rd even at slow speeds. At the time, I didn't know about the trans temp issue, but just didn't like the engine being so buged down. I shifted to the manual mode for the remainder of the trail, but wondering if using one of the MTS modes would help?I actually did a little experiment with this today on a trail, drove the entire thing in S1, since the trail was best at around 10mph.
I noticed on the longest climb of the trail the trans temp got up to 240F, as indicated by my Scan gauge, which was about 3/4 the way to the red bar on the cluster trans temp gauge. It never overheated but I was curious if it would stop climbing, didn't find out since I summited the peak and then we were descending.
I didn't feel like the climb necessitated 4Lo because it wasn't that steep, and I assume at 10mph the truck can just lock the torque converter anyways and reduce the heat being pumped into the trans.
RPMs were around 2000-2200, so a fair amount of coolant being pumped through, when I bumped it into D it immediately shifted to 2nd.. which seemed too low for the grade, which I calculated at about 10%.
I think the initial gear you see when you select manual shifting mode isn't the gear the truck is in. It's just the maximum it'll shift TO.
Correct, "Manual" mode in the automatics is a limiter. It only allows the trans to climb to the gear displayed, so S3 maxes out at 3rd gear, S2 maxes out at 2nd, etc.I think the initial gear you see when you select manual shifting mode isn't the gear the truck is in. It's just the maximum it'll shift TO.
It's possible it was in 2nd which is still too long for some offroad situations.
We're going to go up La Gloria road Friday, I'll use the "current gear" gauge on my Scan Gauge and see what it does in S mode.
Agree. And the first step when a vehicle goes into limp mode during normal operation (e.g. mapped actual dirt road open to all traffic), should be to report this as a vehicle safety defect to NHTSA. This may be considered a "loss of motive power" which is very serious. When you have the engine throttle down to a very very low speed, well below what you had been safely driving, that's a major safety issue for the driver and occupants. Alpine weather changes quickly, and this kind of thing can put you into a safety situation.
What's interesting is I've seen up to 200F trans temp just driving around on the street. The gauge on the dash doesn't move from 150F to 215F from my experience.
I tried this too in my 4Runner. I put it in S2 on-road in a place I couldn't go any faster than 20 mph and it helped but I don't feel like I should have to do this. I climbed the same hill in my Honda Accord in regular drive no problem.I actually did a little experiment with this today on a trail, drove the entire thing in S1, since the trail was best at around 10mph.
I noticed on the longest climb of the trail the trans temp got up to 240F, as indicated by my Scan gauge, which was about 3/4 the way to the red bar on the cluster trans temp gauge. It never overheated but I was curious if it would stop climbing, didn't find out since I summited the peak and then we were descending.
I didn't feel like the climb necessitated 4Lo because it wasn't that steep, and I assume at 10mph the truck can just lock the torque converter anyways and reduce the heat being pumped into the trans.
RPMs were around 2000-2200, so a fair amount of coolant being pumped through, when I bumped it into D it immediately shifted to 2nd.. which seemed too low for the grade, which I calculated at about 10%.
