458

I have a 1996 toyota t-100 sr5 and the four wheel drive recently stopped working. When i shift the truck into four wheel drive the light does not come on but i do hear a click in the dash area. When i get under my truck to turn the front drive shaft it will turn in two wheel drive but in four wheel drive it locks in and will not turn. I am hoping i don't have to replace the whole front differential. Please write back with any ideas before i have to take it to the dealership and get raped.

thanks,
458

tc

Not familiar with the T-100, but using the search should come up with a ton of info.

Welcome to Yotatech

jrfast

this should be normal operation. There should be a 2wire plug that has a sensor either on the transmission or on the front diff that turns the light on, just the light. Your drive shaft wont move if it is in 4wd and all the wheels are on the ground. if this plug is disconnected or broken the light wont come on but you 4wd should still works, this counds like your problem. Joe

marko3xl3

It's normal for your front driveshaft to lock in 4wd when wheels are on the ground. I believe it's just your light...probably burned out.

Flamedx4

Does that year T100 have the same front end as the 95 and older pickups or the 95.5 and newer Tacos? Either way, I believe you have ADD in the front. Assuming ADD.

Re the light - there's a switch on the transfer case and a switch on the front axle ADD mechanism. When both the tcase and the ADD are engaged for 4wd, those two switches are closed and the power goes to the light on the dash. The power also goes to the ADD solenoids to switch the vacuum to the ADD mechanism on the front axle. I would troubleshoot the light first. Find the switches, check the plugs. Get a test light and check that they work. That might solve it. If not, it will probably lead you to looking at the ADD system.
In 2wd you should be able to turn the front driveshaft by hand.
If the transfer case does shift into 4wd, the front driveshaft would not turn by hand no matter what.
If the ADD operates properly, then if you jack up one front wheel and rotate it, it won't turn. If the ADD didn't operate, one front wheel will turn freely.
The ADD having worked, now the light should come on.
If the ADD doesn't work, that's another troubleshooting issue. First check the vacuum lines at the axle mechanism, then under the hood at the solenoids. Next would be electrical checking of the solenoids.