03 Tahoe auto 4wd works, regular 4wd doesn't

[Paulio91184]

Hello, first time poster here. The last time i pulled my boat from the water the ramp was muddy and i had rear wheel spin. I put it in 4wd high and nothing, rear wheels just kept spinning. However, Auto 4wd worked just fine and hauled the boat right out and had great traction. I've since tested it about 10 times and its always the same result. Auto 4wd works and regular doesn't. My mechanic had it on the lift and said it was working while in the air but im still having problems.

 

[rockola1971]

Are you putting it in 4wd high as you are sitting on the ramp getting ready to pull forward with the boat or are you back down the ramp already in 4wd?

 

[Paulio91184]

Are you putting it in 4wd high as you are sitting on the ramp getting ready to pull forward with the boat or are you back down the ramp already in 4wd?

When the wheels started spinning i stopped, put it in 4wd then just tried again. Am i supposed to let it roll a little first?

 

[PG01]

When the wheels started spinning i stopped, put it in 4wd then just tried again. Am i supposed to let it roll a little first?

Normally it should go into 4H ‘on the fly’ sitting still or moving, 4L you should be moving slightly in neutral. When you switch to 4h does it light up(button) or start flashing and go bacck to 2wd? Try on level ground in neutral moving under 5mph switching to 4h and see what happens.

 

[Paulio91184]

Normally it should go into 4H ‘on the fly’ sitting still or moving, 4L you should be moving slightly in neutral. When you switch to 4h does it light up(button) or start flashing and go bacck to 2wd? Try on level ground in neutral moving under 5mph switching to 4h and see what happens.

4hi light comes on fine. No issues. I forgot to add the service 4wd nessage came on when i first got it in back in okmay but it was only on for a few minutes and never came on again.

Also, if i have the key on engine off i can hear the motor actuating but im not sure if something could be broken.

I'll try your suggestion first and report back.

 

[retiredsparky]

The actuator is working ok, because it is used both in auto and in manual. And your auto works ok. The problem must be the dash switch for the 4High.

 

[rockola1971]

Try rolling foward on flat ground and put in 4wd hi. If it works ok then its probaly your synchronization going on up in the actuator on the front differential.