Transfer case problems in 2 hi (not the usual)

[scottg918514]

I've been trying to diagnose neighbor's transfer case woes. He has a 2005 Z71 Suburban. He noticed that while in 2hi, sometimes he wasn't getting power to rear diff, just revving engine, he put tc in 4 auto and/or 4 hi and he was good.

I've done a lot of repairs on my 2 NBS Tahoes, so he enlisted my help.

1. I put tc in neutral to try to "reset" everything, no fix
2. I had him buy a new 4wd switch, put that in, no fix
3. I jacked up rear (thinking, possibly that while in 4wd, only front getting power, but while in 2 hi, not power to rear, as expected, but we do get wheels turning in rear when tc in 4auto.


Also, when 2hi flakes out and you put transmission back into park, nice pleasant grinding noise.

I still think it is electrical because (1) tc is somewhat built proof and (2) sometimes 2hi works. I'm thinking the next logical swap would be the tc module under dash.

I did a few searches, but didn't find this particular issue and the 4wd systems tend to have many different quirks. Anyone have this issue before? What was the fix?

 

[scottg918514]

Anyone????

 

[Dberdusco]

More than likely in my experience as a 16 year transmission tech..... You more than likely have a bad encoder motor...... It is the deal that bolts to the side of the transfer case with three bolts and one or two connectors......

Sent from my SPH-L900 using Tapatalk 2

 

[livingez_123]

I was think it was the shift motor for the TC or as it was called above the encoder. it sounds like it's failing into neutral. too bad we can't put a manual shifter on these electronic TC's

 

[Ken Kavanaugh]

More than likely in my experience as a 16 year transmission tech..... You more than likely have a bad encoder motor...... It is the deal that bolts to the side of the transfer case with three bolts and one or two connectors......

Sent from my SPH-L900 using Tapatalk 2

Howdy, I realize yours is an old post BUT, hoping you're still out there BC this is EXACTLY what's happening to my '05 Z71. Also, I smell burnt oil occasionally as well. Mine slides into neutral while driving down the road, and will grind horribly when putting it into park. Ever since the problem arose I've been running on "AUTO 4WD" without any issues. I DO get a whiff of a terrible burnt oil smell sometimes. FYI I have a leaky tranny gasket too, so this could be the oil stank source. Regardless, I need to fix it and wondered what you ended up doing? Did you ever figure it out? Can you share? Sure 'preciate it...

 

[Fless]

Welcome to TYF.

The dude you quoted was last seen here nearly 5 years ago, so don't expect an answer. Best to start your own thread...