Mountaineer AWD, binding on sharp turns

[zero_chance]

I have an 00 Merc Mountaineer AWD 5.0. When Im going slow and doing sharp turns like in a parking lot, the truck slows down like its getting axle windup. No noises or anything but its definitely noticeable. Anyone else have similar issues? Is windup even possible with an AWD setup? Is this the start of a problem or normal?

 

[ericautopart]

Sounds like the front drive shaft, very common issue with your truck. I've got them if you need one just PM me. You can take the shaft out and drive the truck around..see if the problem goes away before spending money. Just some advice DONT GET A REBUILT ONE. The front prop on the 5.0s are in use WAY too much and it's not money well spent.

 

[zero_chance]

Im assuming youre referring to the actual driveshaft that links the TC to the front diff and not the halfshafts, correct?

 

[ericautopart]

Right, fron't diff to tcase. Not the CV axles..

 

[IZwack]

I would remove the front driveshaft and take it for a spin around those tight turns again. If the binding is gone, then your transfer case's viscous clutch mechanism needs attention. If the problem does not go away, one of the axle's differential needs attention.

Just note that it is advised that you do not leave the front driveshaft out on a day-to-day basis because the vehicle eventually "creeps" forward when its Parked on an incline w/o the front driveshaft. However, it is fine to remove it for diagnosis.

 

[gijoecam]

Sounds like the front drive shaft, very common issue with your truck. I've got them if you need one just PM me. You can take the shaft out and drive the truck around..see if the problem goes away before spending money. Just some advice DONT GET A REBUILT ONE. The front prop on the 5.0s are in use WAY too much and it's not money well spent.

OK, humor me: What would lead you to that conclusion? How could a bad front driveshaft cause driveline bind-up when turning?

I would remove the front driveshaft and take it for a spin around those tight turns again. If the binding is gone, then your transfer case's viscous clutch mechanism needs attention. If the problem does not go away, one of the axle's differential needs attention.

Just note that it is advised that you do not leave the front driveshaft out on a day-to-day basis because the vehicle eventually "creeps" forward when its Parked on an incline w/o the front driveshaft. However, it is fine to remove it for diagnosis.

Ditto on both points. The problem is likely the t-case. With the way it's designed, the viscous coupling could fail in one of two ways: Open or locked. I suspect yours is the latter. It's not exactly a rare occurrence, but it does happen.

 

[ericautopart]

A bad prop shaft can cause a binding feeling due to the bearings in the CV head getting mashed into each other. I'm sure you know a lot, probably more than I do about explorers but when you sell that specific part all day long and that's the complaint from the customer..a new prop fixes their problem 99.9% of the time wether or not you beleive it.

 

[gijoecam]

A bad prop shaft can cause a binding feeling due to the bearings in the CV head getting mashed into each other. I'm sure you know a lot, probably more than I do about explorers but when you sell that specific part all day long and that's the complaint from the customer..a new prop fixes their problem 99.9% of the time wether or not you beleive it.

I make no claims about my knowledge. That's why I asked the question.

Here's the thing though: The front driveshaft is turning all the time. The CV head can't cause bind-up only when turning. If the CV is binding, it's going to bind all the time, not just when turning. When bind-up occurs, it's going to make the front driveshaft make more noise (like mine does currently) but it's not going to cause the bind-up. It's physically impossible.

A binding CV head cannot cause driveline bind-up. Driveline bind-up is caused by a difference in the distance that the front and rear wheels have to travel when cornering. The center differential (actually a planetary gear set) in the transfer case is responsible for allowing the front and rear outputs to turn at different rates. The front and rear outputs are coupled by the viscous coupling. If the VC fails in the locked position, it will resist allowing the driveshafts to turn at different rates, which results in the bind-up (the same way a conventional t-case locked in 4wd acts).

Now, when bind-up occurs, if the front driveshaft CV head happens to be bad, it *may* cause noise from the front driveshaft. But the reverse cannot be true... the driveshaft is in no way responsible for causing the bind-up. It's just not possible.

-Joe

 

[phlawford]

2000 Explorer does similar.

My 2000 often has this binding and sometimes a "rubbing" noise when in a sharp turn.

I never seems to hear it when there is a lot of snow and ice,

The 4H 4L lights flash on and off most of the time, noticeably after I have gone over 60KPH.

The 4H works via the switch, very obvious in the snow.

I am wondering if the 4H auto is trying to engage 4H when I am turning, or perhaps it is trying all the time. Not noticeable on a straight road or gentle curves.

Question

If I do the BWM, is it likely that this binding and rubbing will disapear ?

I don't want to spin the back wheels for even 2 feet. let alone 2 blocks, so will having the 4WD auto disabled via the BWM do any harm.

Thanks

Peter
Winnipeg

 

[Mbrooks420]

The flashing lights mean there is a fault in the 4wd system. Its the 4wd system check engine light. I'd get the codes scanned to find the real problem. The BWM might be a band aid "fix" to your problem. Many members have used the BWM without obvious problems.

 

[steel]

I would remove the front driveshaft and take it for a spin around those tight turns again. If the binding is gone, then your transfer case's viscous clutch mechanism needs attention. If the problem does not go away, one of the axle's differential needs attention.

Just note that it is advised that you do not leave the front driveshaft out on a day-to-day basis because the vehicle eventually "creeps" forward when its Parked on an incline w/o the front driveshaft. However, it is fine to remove it for diagnosis.

Wouldn't using the parking brake resolve the issue of the creeping while parked or is there something else I am missing?

 

[steel]

Can this cause additional damage if it is not fixed right away?

Mine is binding up and it sounds awful. THe whole front end pops.

 

[tsizemore]

I have a 97 Explorer that was doing the same thing. I did the brown wire mod and the problem went away. just my .02 worth

 

[sean99]

I have an 01 awd 5.0...99% viscous coupling?

 

[Mbrooks420]

The front diff will still turn with no front shaft installed since it has hubs that don't unlock. Pull the front shaft and see if the noise goes away or changes. It's possible it could be the shaft as well, they are a commonly failed item.

 

[sean99]

Can it be the front shaft based on this info from gijoe?...I'm not getting any popping or other noises, just binding when turning.

Here's the thing though: The front driveshaft is turning all the time. The CV head can't cause bind-up only when turning. If the CV is binding, it's going to bind all the time, not just when turning. When bind-up occurs, it's going to make the front driveshaft make more noise (like mine does currently) but it's not going to cause the bind-up. It's physically impossible.

A binding CV head cannot cause driveline bind-up. Driveline bind-up is caused by a difference in the distance that the front and rear wheels have to travel when cornering. The center differential (actually a planetary gear set) in the transfer case is responsible for allowing the front and rear outputs to turn at different rates. The front and rear outputs are coupled by the viscous coupling. If the VC fails in the locked position, it will resist allowing the driveshafts to turn at different rates, which results in the bind-up (the same way a conventional t-case locked in 4wd acts).

Now, when bind-up occurs, if the front driveshaft CV head happens to be bad, it *may* cause noise from the front driveshaft. But the reverse cannot be true... the driveshaft is in no way responsible for causing the bind-up. It's just not possible.

-Joe

 

[Mbrooks420]

He is correct if it pops only in the turns I would suspect the t case or a front cv shaft

 

[td1042k]

Bringing this back from the dead... I have a 1998 XLT 5.0 AWD, but I only seem to have the issue of the front end binding up after i've driven the truck for a while and everything is warmed up.

I have zero issue with driveline binding when the vehicle is cold or has sat for several hours. Wehn it is warmed up and I pull into a parking spot, it will bind up. When I put the truck into park and shut it off it seems like I'm hearing the driveline unwind itself, through what sounds like several clunks, letting go little by little.

All four tires are brand new, same size, same air pressure. I've tried taking out the front propshaft and it does eliminate the issue, but I would rather still have the AWD and not have the truck creep while in park (drifted out of a driveway overnight into a cul-de-sac once).

But anyway, does this sound like the transfer case viscous coupling? Another thought was, do I have a limited slip front differential? Could it be the gear oil is low or needs changing and the front diff is getting hot and clutches locking up?

Any insight would be appreciated. I've owned this truck for about 6 months now and I'm learning more and more about it every day, thanks to this forum. Thanks guys!

 

[td1042k]

Bump for a reply...

 

[IZwack]

Yeah sounds like the viscous coupling.