How wide of tires can I put on my 4x4 truck - 1990 Toyota Pickup

So what you are saying is that when you put your truck in reverse, the front and rear tires both rotate, but when you put it in drive, only the rear tires turn and not the front? If so, you will need to put the truck on a lift and watch the driveshaft to the front tires. Check to see if it rotates both in drive and reverse. If it does not turn in both directions, you may have a problem i the transfer case. If the driveshaft in front is turning but the tires are not. then you can have a problem with the front axles or 4x4 hubs.

Tire probably will fit, but you should use tires in pairs of the same size

All tires on a 4x4 must be the same size or there will be a transmission wind up , you could damage the transmission and jam the gear change.

Those older fords you have to put the 4x4 selector into 2H or 2 High on the floor shifter. Then go to the front tires and in the very center of the tire there will be a knob that say Locked and Unlocked. Turn the knob to unlocked on both sides. Then you will not have front wheel dragging on the drive train and only the rear wheels will be the drive tire. TO put it back in 4x4. Turn the knob back to locked on each front tire and put the truck in 4H or 4 High to get 4x4. Only use 4L or 4Low when your stuck to prevent spinning your tires with full power.


Now if your has the automatic locking hubs I would switch them out with manual ones because the automatic ones were problematic where they get stuck or not work at all. It requires replacing the locking hub assembly which isn't that hard to do.

There could a wide variety of problems.Loose lug nuts,bad wheel bearings,bad ball joints,or a broken belt in the tire,You really need someone qualified to look at it.

Yes...
The tire sizes are important on any 4X4 vehicle... IF you engage the 4X4 ... or is you have an AWD vehicle...

If the tires are different sizes , front and rear... then the front and rear axles will turn at different speeds... not in sync with the gearing of the transfer case.

Unless this vehicle is being driven on snow , ice or mud.... while in 4x4 mode... this is very bad.... for axles and transfer case...

sounds like u are having front drive line problems. the press button 4x4s are not a good idea to have. transfer cases go out very easily. so check front drive line.

You can put it in 4x4 when you are dring straight and have no tires spinning , if you want 4x4 you must stop put the vehicle in neutral hold the brake and go to low range and must do the same thing going back to high

Well I would say yes if it is the new body style and 4x4.Even 2WD you may have to turn up the torsion bars then get the front end aligned.The rims don't matter how tall just wide.I have 2002 4x4 1500 with that size,but not sure what was stock on mine.I also installed the after market torsion keys that will allow for up to 33"tires.Well hope this helps and good luck.

Do you have all 4 tires matched to each other? If you have 1 worn and 3 new, expect problems. Also, 2 tires on the front from 1 mfgr and 2 on the rear from a different mfgr will cause no 4WD. If all 4 tires match, put it in 4WD and tap on the transfer case and the front shift mechanism on the front axle. One or the other may be stuck, assuming that the 4WD fuse is good. The fuse is in the fusebox under the dash.