awful grinding noise shifting from 2hi to 4hi

[Will_4R]

The other day I tried shifting from 2hi to 4hi and got this awful loud grinding noise. I quickly put the dial back to 2hi (and I think it continued grinding for a second or two - I can't remember), waited a few seconds and tried again. Same offensive sound. I was on the highway going around 50 mph, in a stright line, and the tire were not slipping. I pulled over to a cut out and tried at it at a crawl, and no problems. Anyone know what happened, or what it happened? Should I be worried? I have had the truck for a couple years and shift between 2 and 4 hi all the time without this problem. (Actually it has happend a couple times: once when I started to turn before it was engaged, and the other time, it only made the grinding noise for a second then engaged.) This time it ground for several seconds and wouldn't engage.

 

[manhunter]

Just to make sure what you are saying, ....., you are switching to 4wd on the fly from 2hi to 4hi by pushing in the button on the left side of the 4wd shifter? If you are going under 60 mph, there should be no problem. Not sure what the grinding noise is, mine has never done that. Maybe some others can shed some light on the issue.

 

[Will_4R]

Just to make sure what you are saying, ....., you are switching to 4wd on the fly from 2hi to 4hi by pushing in the button on the left side of the 4wd shifter? If you are going under 60 mph, there should be no problem. Not sure what the grinding noise is, mine has never done that. Maybe some others can shed some light on the issue.

It is a 2003 (4th gen) the 4wd shifter is a dial to the right of the steeling wheel. I was shifting on the fly, the center diff was unlocked. If I am accidentally going to fast, the thing beeps at me, anbd does not appear to try engaging 4wd. No beeping this time.

 

[Will_4R]

So I went out the other day and tried shifting between 2 and 4 HI and had no problems. This was around 25 mph. I guess what happend on the highway was a fluke, it was just weird that it happened 2 or 3 times in a row like that. It was raining out, maybe the tires were slipping slightly - although I am pretty sure there were not.

 

[jharris2]

It may have been the gears trying to synchronize before engaging. But to be safe, when was the last time you changed the oil in the transfer case?

 

[Will_4R]

It may have been the gears trying to synchronize before engaging. But to be safe, when was the last time you changed the oil in the transfer case?

It was a rather unpleasent sound.
T-case oil was changed at 91,000 km, now I am at 130,000 km. The Toyota maintenance schedule says it should be changed every 32,000 km, so it should be due, but when I took it in for it's last service, at 128,000 (which would be a little over 32,000 km), the dealer said it wasn't necessary?? I thought that was kinda strange. They did tell me I should change the spark plugs, and according to the maintenace shedule they are not due to be changed till 144,000 km. Maybe the dealer is out to lunch.

 

[pmrowczynski]

Happened to me a several times.

- Fresh fluid in a new car (<10k miles) and even after I went to synthetic (>30 and <50k).
- Moving (~5mph) or standing still (drive or neutral).
- Uphill or downhill.

I just let it roll a little and try again. Thought it was "normal" because the gears may not be 100% matched up.

Maybe 10-15 times total in the last 2 years.

 

[jharris2]

It was a rather unpleasent sound.
T-case oil was changed at 91,000 km, now I am at 130,000 km. The Toyota maintenance schedule says it should be changed every 32,000 km, so it should be due, but when I took it in for it's last service, at 128,000 (which would be a little over 32,000 km), the dealer said it wasn't necessary?? I thought that was kinda strange. They did tell me I should change the spark plugs, and according to the maintenace shedule they are not due to be changed till 144,000 km. Maybe the dealer is out to lunch.

If the maintenance schedule calls for it they should have done it. Normally, you have to watch that the dealership doesn't ADD anything to the maintenance schedule!

Normally, I shift into 4WD at 25-30 mph, no load, going straight. Takes 4-5 seconds to switch. If the vehicle is not going perfectly straight, it sounds like it's binding and takes a lot longer. Maybe that's what happened to you?

 

[CJ3Flyr]

IMHO it may be normal...


You must keep in mind that while tarnsitioning the center diff is locked, it has to be. Once the front axle locks then the center diff lock releases. If during the gear alignment/engagement process you were turning a corner the driveline will bind just like driving on pavement with the center diff locked. As the center diff tries to unlock (if bound) it'll clunck, bang and grind some.


The solution? Shift to and from 2hi-4hi on straight roads at low speeds. I find below about 35mph with some light accelerations and deccelerations helps. If have trouble do a few gentle swerves, if you still don't get it switch back to the previous mode and try again. IMHO switching is a PIA. Overall the Torsen t-case is so cool it's worth the trouble.


You can, in theory, make the 2hi-4hi switch up to 62.5mph/100kmh and the 4hi-2hi at any speed. If you are out of the Toyota recommended envolope it won't do anything but beep at you. I find that lower speeds seems to work better.

:cheers:

 

[Climr]

I've had a lot of trouble myself lately with shifting from 2HI to 4HI. I usually drive around in 2HI in town, other than in snow, but shift into 4HI almost every day so that I can park on snowbanks at school (I'm easily entertained). I frequently have to wait greater than 5 seconds and have waited as long as approximately 15 before switching back to 2HI in frustration and finding a snowbank-less parking spot farther away. Should I be worried, or is this a fairly common occurence in t4r's?