when i bought my truck (2002 silverado 2500 hd 4x4 automatic) the dealer told me to only switch the truck into 4x4 when it was stopped. it's got the mechanical on the floor lever. now my cousin has the same truck and does it "on the fly." wtf? is there a correct way?? how fast can i be going when i switch from 2wd to 4wd and 4wd to 2wd?

--matt

 

I do it on the fly all the time, but i have the push button. I'm not sure if the mechanical lever is different. I've switched to 4x4 close to 40-50mph driving through the snow with no problems.

 

You can go from 2wd to 4-HI while driving. You have to be stopped to put it in 4-Low.

 

i had the floor shifter in my silverado. i would go 2wd to 4hi on the fly all the time. in maine it would snow and i would be cruising along in 2wd and hit snow on the road and reach down and rip it back and go. never clunked or anything just instant traction. if your spinning your tires and you try to go into 4hi it just won't engage until they stop spinning. i know i tried. the front end has an actuator on it also that disengages the front end. your owners manual should also tell you all this info did you look in it? i think it says like 55mph max or something like that. but you have to be stoped and in nuetral to go into 4lo.

 

i do it "on the fly", however i'll usually put the truck in neutral and let off the gas, then switch it to 4wd, then put it back in drive. i have the manual on the floor as well.

at the track though, i launch in 4wd and switch it out after the 1-2 shift with my foot to the floor. still works.

 

Yup, only time you need to stop is to put it into 4 Low.

 

Pretty sure you can do it on the fly to 4hi, but 4low must be done stopped and in neutral. My buddies truck is like yours on the floor and this is the way he uses his, my truck is push button and it works just like his only I have Auto also.

 

Thats what I do in my 89, Ive taken it in and out at like 45, never had a problem.

 

Ive never seen a truck that u need to stop and shift it into 4hi and back out. You can do and 85 truck on the fly. Just step off the go juice and shift er in.