[twtower1]

Hi .
Im new here, and really hope someone can help me.

I have an 02 silverado 1500. Purchased about a year ago. Truck had a bad front diff. I had one put in and all was good, until it wasn't.

The truck shifts into 4hi with no issue, but struggles to get back into 2 hi. It will if I continuously mess with the buttons, usually when rolling backwards on gravel or grass.

Service 4wd is illuminated.

No odd sounds.

I have put a new dash switch, front actuator, transfer case encoder motor and even swapped out the tccm from the same year truck. Problem still exist.

What else can I do.

I do have 20" aftermarket wheels with wide tires. Don't know if that is pertinent or not.

Any advice appreciated.

 

[RayVoy]

Hi, welcome, get the OBD2 codes read that will tell us where the problem is.
Not all readers can read 4x4 codes, go to a parts store and they will read for free.

 

[j cat]

you use a GM code reader engine/drive train/abs codes .............
look up the transfer case fluid .... looks blue ... trac II fluid transfer fluid ..

 

[twtower1]

Turns out the transfer case was low/dirty. Never trust your jiffy lube joints past oil changes. Bought 3 qts of the blue from the dealer.

 

[j cat]

when you use a tow or a load in the truck change the drive train fluids 40-50K miles. then inspect the fall season to inspect all the fluids total... rotate tires and inspect the brakes ...