4H not disengaging?

[enkrypt3d]

When I engage 4H it seems to make a difference in handling (heavier steering, wobble on tight turns etc) But when in 2H, and driving inside a slick concrete parking deck, I can hear the front tires squeal when I accelerate..... or is this just under-steer? I guess the only way to tell is to jack up the truck and ensure that the front end is not turning when in 2H but is there anything else I can do? I just had the front axles replaced... but not the hubs - could the hubs be locked up somehow? Even if they were, the transfer case would not be sending power to the front diff right?...... thanks

[AndyC]

Not sure how often you're engaging 4hi, but did you make sure to back up a few feet to get the hubs to disengage?

[RedPath88]

 

And auto hubs have occasionally been known to stick (on and off) so that could be. If the half shafts were just replaced, it may be possible that it was not reassembled properly and one or both of the hubs is jammed. But start with AndyC's recommendation first, back up 5-15 feet and then drive and see if it feels more like it should in 2WD.

 

Also, find a softer/loose low traction surface, such as dirt or gravel and spin your tires from a stop, only need them to break traction, then get out and see if either of the front tires spun.

[Precise1]

Obviously follow the good advice above, but...

 

But when in 2H, and driving inside a slick concrete parking deck, I can hear the front tires squeal when I accelerate.....

Mainly when you turn, right? Perfectly normal, almost all vehicles do that. Next time you are in a garage, stop and listen, it'll sound like prom night parking lot non-stop...

Uhh, tires squealing, that is...

 

B

[Slartibartfast]

Yep, normal, sort of like how your shoes squeak on highly polished floors. If you were making tight turns with it in 4x it would bind up and then the tires would sort of skip, or else make the driveline bind up until the truck wouldn't roll without considerable application of power. Long story short, if it's in 4x going around a parking garage, you'll know something's wrong.

 

And you're right on the transfer case. Even if your hubs are stuck (or you just didn't disengage them), if the stick is in 2h, the front end is not driven by the transfer case.

[enkrypt3d]

yes I know that the slick pavement will make noise on any tires when turning but I'm talking about when I hit the gas, the front tires squeal not the rear which doesn't make any sense....... since it should be RWD in 2H.

[enkrypt3d]

Or is it just from understeer? the rear wheels pushing the front wheels while turning making them squeal as if power is being delivered to them? And yes I have an NSX and the tires squeal all the time but not the front ones when I'm accelerating and that car has 3x more power than the pathy.

[Slartibartfast]

Keep in mind that Pathfinders are large, underpowered, and (at least in my experience) difficult to do burnouts in. I don't think that wheelspin or understeer are what's making the noise. Think of it like this... when you go around a turn, the driver's and passenger's side wheels go different distances, right? The same thing is at play on a single tire. The edge of the tire on the outside of the turn has to go a little farther than the inside edge, but of course there's no way one sidewall can spin faster than the other (barring catastrophic destruction of the tire). So it has to slip a little. This slippage is not reliant on the wheel being powered, and it'll get worse the harder you steer, the faster you go, and the larger the contact patch is (the width of the tire and how squishy it is... depends on sidewall strength and inflation pressure).

 

I also suspect that the steering angles get a little wonky approaching full lock, so the front tires may be fighting each other a little on sharp turns, just due to the design of the linkage. My understanding of steering geometry doesn't go much past knowing that there's a thing called an Ackerman angle though, so don't take my word for it.

 

Keep in mind that a Pathfinder is a heavy, underpowered vehicle, which in many cases is fitted with fairly wide and squishy tires. From what little I know of NSXs, they're small, powerful, and fitted with comparatively firm tires. I would not be at all surprised if the NSX squealed its rear tires under acceleration. I would be very surprised if a Pathfinder did the same.

 

If the squealing is excessive you might want to check your tire pressure. Otherwise, unless it's squealing in a straight line, or wobbling/understeering like it's in 4x, you're good to go.

Edited June 2, 2013 by Slartibartfast