My 2006 mmh has been whining for two weeks. This afternoon, Clunk. Bang. Now it sounds like I am dragging cans. Take a look, smelled the gear oil. Uh-oh. Yep, cracked transfer case. I can see the cracks and the shaving filled oil. How hard is this to DIY? How dangerous is it to drive as-is? Thanks.

 

From my research, the "dragging cans" noise, and the smell, are the exact symptom of the failed PTU. I have no advice re. DIY and whether you should drive it.

 

A bit more about mine. It's a continuous "rrrrrrrrrrrrrrrrrrrrrrrrr" noise, definitely not a whine. As I said before, it varies pitch corresponding to speed changes. There is no correspondence with engine rpm. It does not change when cornering, so I don't think it's a wheel bearing. Throttle position doesn't seem to change it much, so it's easiest to hear when coasting, and hardest to hear over engine noise when on the gas. It doesn't vary according to circumstances when the rear wheels are engaged, as it should if it's the rear coupling. I think I'm starting to feel very faint vibration in the steering wheel when it's loudest.

I had the fluid in the eCVT changed, with no effect on the noise.

So, subject to correction, I think the diagnosis of the u-joints being the prime suspect seems to fit the symptoms the best.

 

Oh I guarantee it's the PTU- I can see the cracked metal housing. My concern is whether I am damaging the front wheel drive by driving it despite the noise.

 

I believe it will fail soon. How will it fail?

If you're lucky it'll quit sending power to the rear axle.
If you're not… it may lock up your drive train…

If you're handy with tools, it's a bolt up job.
Not hard… but get the shop manual.

 

Thanks for the encouragement. Is this a hybrid only PTU, or any 4x4 escape? Anyone know the latest model PTU to try and get used?

 

I don't see any reason why the Hybrid and non-hybrid Escapes would use different PTU's.

I went under mine today to take a look at the driveshaft. I couldn't see any visible sign of problems with the U-joints, and prying at them revealed no free play. I did get a bit of movement where the driveshaft goes into the PTU, a few degrees of rotation or about 1/4" of movement. If the PTU is supposed to be tight, then that may be where my problem is. But I'm not getting a whining or crunching noise.

 

Anything with gears will have a certain amount of backlash or movement and you don't how much gearing you were actually moving.

 

Our mechanic had a look at it. Everything checks out ok. The PTU fluid is clear. A test drive didn't reveal the noise, but they only drove it a few blocks. It doesn't show up for me until 15-20 minutes into highway driving, as if something warms up before making the noise. It goes from inaudible, to louder than the engine. I guess it will only get worse and easier to track down.

 

Until the u-joints fall apart you can't see much. The end caps holding the needled bearings covers all up. They can be the problem. If the oil in the PTU is clear )I'm surprised given the nosies...) then look at the u-joints... I've found they last about 100k.

If its not the ujoints then either the differential of the transaxle itself...