91 P/U 4X4 grinding problem

[books190]

Hey, I have a 91 P/U that when shifted into 4wd it makes a fairly loud grinding noise and vibrates a bit. Also when I try to shift it out of four wheel drive it fails to go back into 2wd unless I slow down and turn the wheel full left or right, then it goes back into 2wd and drives fine. Any insights into my problem would be a great help.

Thanks,

Brian

[Sidney]

As stated in the sun visor oil & lube card,owner's manual and factory service manual the 4wd cannot be engaged on dry pavement as the transfer case does not have a differential gear to compensate or certain wheels spinning out of sequence in comparison with the others:

http://www.showmesome.info/hilux/info/faq.htm

I copied & pasted the message:

"CAUTION:
The 4-wheel drive modes should not be used on hard/dry surfaces, especially when manouvering or turning sharply, damage could result"

"Why can't I use 4x4 mode all the time or on the roads?
There's drive to both axles and the front and rear axles have different turning circles. On hard/dry surfaces like tarmac there's no give on the road surface so you'll end up with windup on the transmission which can destroy it.
Permanent 4WD vehicles like Range Rovers have a differential in the transfer case to allow it to slip as you turn in circles. The Surf is not intended as a permanent 4WD vehicle. "

Also make sure that all 4 tires have roughly the same amount of thread wear (I assume that they do).Regarding shifting back into 2wd you must drive backwards for at least 10 feet when difficulty occurs as stated in the owner's manual.I usually when driving in 4wd I press the gas quickly and then quicklu let go of the gas pedal then quickly shift into 2wd with not problems.

Sidney
Repairs tv's,vcr's,home/car audio out of my home
E-mail:sidneybek@yahoo.com
Dartmouth,Nova Scotia
Canada
1985 Toyota 4-Runner,22R-E,W56,RN60LV-MSEK,rusted rear step/towing chrome bumper with 243 000 KM

[reb]

I have had no problems shifting any of my 4WDs into or out of 4H on the move. Back off the gas pedal as you shift in or out. I have not had to press the pedal quickly before shifting. It is important that all four tires be the same size and inflation. That is the most common cause of having to back up or turn hard before it goes into 2WD. Another, but not too likely possibility, is that a previous owner swapped differential ratios in the front or the rear.