Question about 4x4 and tight turning drivetrain "drag"

SFHLibertyCRD · **Posted:** Thu Oct 16, 2014 12:28 pm

Hi all, one other thing I noticed on the Sierra trip last weekend that I wanted to ask about:

When in full-time four wheel drive, I noticed that when I had the steering wheel all the way turned for a tight u-turn, the car did not want to move forward easily, at least not happily. It felt like there was some kind of drag in the drivetrain. You could push through it with enough accelerator, but it did not feel like a normal condition. Is it? If not, then what does it indicate? Low fluids? Differentials needing service? Something in the steering, tranny, transfer case?

I have a '05 with Selec-Trac.

greiswig · **Posted:** Thu Oct 16, 2014 2:03 pm

If you only have or are using 4WD and not AWD, then there is no differential between front and rear axles. So yes, it will bind up a lot when turning. So much that you may start breaking things...hopefully just a U joint, but I've seen halfshafts and other things break, too.

Don't use 4WD on surfaces that don't allow slippage. That includes dry or only wet pavement, Moab sandstone, concrete, etc.

SFHLibertyCRD · **Posted:** Thu Oct 16, 2014 2:07 pm

I was in "full-time 4WD" which from my understanding from the owners manual is the same as what you describe as AWD:

"This transfer case is equipped with an inter-axle differential which allows driving the vehicle in the 4 FULL TIME position at all times on any given road surface
including dry hard surfaced roads. The 4 FULL TIME mode allows the front and rear wheels to rotate at different speeds which eliminates driveline binding and
component wear that is normally associated with driving the vehicle in the 4 PART TIME position on dry hard surfaced roads. This feature provides the safety, security, and convenience of operating in 4–wheel drive at all times regardless of road conditions."

greiswig · **Posted:** Thu Oct 16, 2014 2:38 pm

Okay, then it sounds like it may not be shifting all the way into AWD. That transfer case goes from 2WD to 4WD and then to AWD, so it may not be getting all the way to that last step.

Have you checked the linkage and cable out? Search for that here, too, and you'll find some helpful info.

SFHLibertyCRD · **Posted:** Thu Oct 16, 2014 2:43 pm

greiswig wrote:

Okay, then it sounds like it may not be shifting all the way into AWD. That transfer case goes from 2WD to 4WD and then to AWD, so it may not be getting all the way to that last step.

Have you checked the linkage and cable out? Search for that here, too, and you'll find some helpful info.

Thanks, greiswig. It happened noticeably bad once, so maybe you're right that it did not shift all the way that time. I'll have to play around and see if I can get it to reproduce the issue.

flash7210 · **Posted:** Thu Oct 16, 2014 2:58 pm

When it happens to me, its usually when shifting from FT-4wd to 2wd and it somehow gets hung up in PT-4wd. This is why I always try to shift the transfer while slowly rolling in neutral to make sure there is no binding in the driveline causing it to stick.

mass-hole · **Posted:** Thu Oct 16, 2014 3:35 pm

I get the a "tightness" when hard turns are made in Full-Time. Not binding like in Part-Time 4WD, but its stiffer than if i was in 2wd.

SFHLibertyCRD · **Posted:** Thu Oct 16, 2014 3:48 pm

mass-hole wrote:

I get the a "tightness" when hard turns are made in Full-Time. Not binding like in Part-Time 4WD, but its stiffer than if i was in 2wd.

This sounds more like my regular experience, with the exception of the time where it was much more pronounced and I might have been in PT.

Question about 4x4 and tight turning drivetrain "drag"

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