91ToySR5

hey all... i have a '91 toyota pickup sr5 ext. cab V6 4x4 with ADD. if i try to shift into 4wd while moving any faster than about 30mph the shifter won't move at all. if i slow down or come to a stop it shifts in and out smoothly. i do let off the gas when trying to shift into 4wd but still doesn't help. the fluid is in good shape and at proper level.

i had thought i had the vacuum lines on the ADD backwards as i had to R&R the diff prior to this happening. if i switch the two vac hoses it'll shift into 4wd smoothly at any speed, the 4wd light comes on but when i hit the gas i hear a loud clunk and the 4wd light goes back out. swap the vac hoses back the other way, 4wd works great just can't shift into 4wd when moving.

any ideas?

thanks in advance!

rob

Tubbyfatty

Same here. Even when im moving like 20 or so, when i try to put it in 4hi, its still hard, i do have to use some force but it does engage and go in just fine.

But my light stays on and i dont hear a loud clunk. Im sure someone knows whats up.

elblako91

You can engage into 4x4 while moving?? Is this true for both manuals and automatics? I had no idea you could do this.

bpayne88

i dont think that you are supposed to shift to 4wd if you are travaling over 15 or 20 mph any way guys. doing that could seriously f-up your transfer case. pluss why do you need to shift 4wd at 30 mph any ways?

elblako91

See that's what i thought as well. This is my first vehicle with 4x4 and i always thought you had to come to a stop, lock your hubs, hit the clutch and put it in 4 low or 4 high. (At least for manual trannys)

scuba

Why not just stop and THEN shift into 4. Takes what...10 more seconds...? EDIT, To above poster, You dont have to put the clutch in...

bpayne88

if you leave your hubs locked you CAN shift from 2 to 4high only. but you have to have your hubs locked. if you dont then 4wd would be useless any way. and the t-case would grind while shifting.

elblako91

Ok gotcha. Learn some thing new everyday. Thanks

scuba

Yep, And if it occasionally seems hard to shift in and out of 4, Could be the drive line binding...drive straight, forward or backwards, and then you should be ok.

91ToySR5

the owners manual states "to shift from H2 to H4 reduce speed to less than 50mph" etc... so doing this on the go is not an issue. reasons for doing this? driving on a main road that is plowed and then turning onto a side road that isn't plowed. i don't want to have to stop, put it in 4wd and then start up again

i didn't have this problem untill last year. i've been dealing with it, jsut shifting it into 4wd at slower speeds but something is definately causing this to happen and am looking for some insight as to why.

thanks again

rob