Good day. I have a 2011 Silverado LS 4.8l 4x4. I had the rear main seal replaced last year and between then and last spring my 4x4 stopped working. I am not sure if it was from when the rear main seal was replaced or after. I had it looked at by the mechanics that did the rear main seal work. They diagnosed it as the front dif switch actuator. I replaced that with no joy.

The light on the dash does not come on when switching into 4hi or 4lo. I have a manual transfer case. It feels like it is engaging into these gears but wheels are not engaged.

I am looking for some suggestions. I don't know if it was just a connector that was not reattached when the rear main seal was replaced or if it is something totally different.

My 17 yo son is now driving the truck and would like to have 4x4 for our canadian winters.

Thanks in advance

Scott

 

Is the front axle actuator engaging when you put it into 4x4? It's a common occurrence that they go south. It's an easy fix too.

 

We just replaced that with nothing changing. No 4x4 lights on dash and no 4x4

 

Well, I am amiss. I thought a manual TC would have a lever, not push buttons, I do think your TC is a MP1222. It should have a manual lever on the floor, not on the dash, but it may have indicator lights on the dash. Have you looked t see if it has an actuator motor on the TC?. This is a pic of what it should look like, if it's a true manual-shift transfer case.:




If not, you could have a blown fuse, or an actuator motor that has gone bad. You also might want to drain the TC fluid
and see what some out or run a flexible magnet down the fill hole, if not. Might be an internal issue in the transfer case.

 

That is the Shifter we have on the truck. The lights I am refering to are on the dash display when placed into 4x4 either high or low to indicate it is activated. Also when placed into 4lo usually it trigers the traction control to the off position indicated by a light on the dash as well.

I am not sure if it could be a connecter to the transfer case that wasn't connected back when the rear main seal was replaced. I am just not aware of what or where that would be.

I have done some research on youtube to see the process on replacing the rear main seal to see what has to be moved to gain access. But there are not many good examples so far.

Thank you for your replies BTW. Appreciated greatly.
Scott

 

It may sound stupid but check your grounds, especially under the driver door. They tend to rust and there’s a service note on it. Also, with KOEO, have someone listen to the transfer case and the actuator as you shift into 4WD.

 

Thanks for replying! I had it figured out what was the problem. It was the connector on the top of the transfer case. When the rear main seal was replaced the plug was not reattached to the transfer case leaving me no 4wd. All good now for the rest of winter!

 

Yes
there is a contact switch on the tcase...this switch sends power to the front diff actuator. when the shift is made the switch closes sends power to move the actutator.