Bald tires affecting AWD?

[shadowless127]

This is a new occurance.

I will hit it hard from a dead stop and then my acceleration will die, and come back quickly, almost like the AWD is engaging to get traction (it's like the feeling I get when I go through snow and large/deep puddles). If I launch very gingerly it goes fine. This only seems to happen on certain roads, ie the road my office is on, and one of the roads by my house. it happened one time while i was in third gear accelerating lightly on a different road, but not as harsh, almost like it only lost a tiny bit of traction. This last part is what's making me think that AWD is trying to compensate for the lack of tread on my tires.

Trans operation besides this has not changed and has been shifting fine. No telltales have been illuminated at all since I purchased the vehicle.

Tires are extremely bald and i'm due for new tires; everytime I go to get new tires something comes up and WHOOSH, no more tire money.

Thx!

 

[jrford]

Those aren't mixed tires are they? There should be no more than a 1/2" difference in diameter in the tires. How many miles on your rig? From what i understand the viscous clutch is always engaged and slips when needed, and locks up when the F/R axles spin at different rates which heats the fluid up and 'locks' the clutch plates together. .
I have never noticed mine bogging down . . .in snow or otherwise. If you get over a 1/2" they say you could fry the viscous clutch which by the way is a sealed unit.

 

[Fox Fader]

I don't know how it works on Ford products, but on other cars I've sold, new, when trac-control kicked in the the trac light on the dash would flicker as long as the traction was being controlled.
Someone else with the same vehicle can chime in and tell how the Fords work.

 

[shadowless127]

Those aren't mixed tires are they? There should be no more than a 1/2" difference in diameter in the tires. How many miles on your rig? From what i understand the viscous clutch is always engaged and slips when needed, and locks up when the F/R axles spin at different rates which heats the fluid up and 'locks' the clutch plates together. .
I have never noticed mine bogging down . . .in snow or otherwise. If you get over a 1/2" they say you could fry the viscous clutch which by the way is a sealed unit.

They're not mixed tires, but I'm pretty sure they are the original tires that came with the truck and are in need of replacement. The truck has 80K on it. Im embarassed I haven't changed the tires.

AFAIK there is less then 1/2" difference. I'm aware that the clutch can burnt out which is why I won't just go out and buy 2 tires then wait and get another 2.

Like I said, this happens usually from a dead stop with a HARD launch. I'll do some more testing during lunch and see what other information I can come up with.

I don't think it's a trans issue because it doesn't shift or clunk in/out of gear or anything like that, perhaps my IAC is gummed up and when i'm at WOT there's just not enough air?

I don't know how it works on Ford products, but on other cars I've sold, new, when trac-control kicked in the the trac light on the dash would flicker as long as the traction was being controlled.
Someone else with the same vehicle can chime in and tell how the Fords work.

We have no lights on the dash to tell us when AWD/Traction kicks in. Actually, we have an "AWD Lock" light but no one knows if there is an actual lock feature for our T-case's.

 

[rrgone]

You could try to swap one tire/wheel on the front with one on the rear to see if it improves. If so you know you're on the right track.

 

[shadowless127]

You could try to swap one tire/wheel on the front with one on the rear to see if it improves. If so you know you're on the right track.

I was thinking that. I just looked at the tires and the wear is different, but not drastically so I think ima do some tire shuffling.