Yesterday I put my truck in 4hi when I was going through a little patch of slick mud. As soon as I turned the switch the check4x4 light came on but it shifted in and out fine a few times with just the light coming on. I tested it when i got home and everything was working properly with no check light. I decided to try again this am and when I switched to 4hi the whole truck jerked and it shifted to 4 lol somehow I was able to get back to 4x2 from neutral. What is the most likely culprit? Solenoid or transfer motor

 

Any truck will lurch into 4x4 low. It's because of all the low end torque. As for the light I have no idea.

 

Were you moving when you did this ??

 

I was going maybe 5 mph, I didnt put it into 4lo i put it into hi and it shifted on its own to 4 lo. Seems like its working intermittently. It seems to work fine to 4hi when in park but gives me trouble when Im moving. Ive only tested it at slow speeds. Just trying to figure out if its the transfer motor or something else.

 

you are confusing me... how could it work fine in 4H while in park ?? not making sense.

 

It shifts fine to 4hi while in park. The error light only comes on when shifting to 4 hi while moving. This is also when it shifted to 4 lo on its own instead of 4 hi

 

Oh....now i get you..I would look at the T-case shift motor