transfer case/front diff woes...

[hysterwv]

Our '08 EL Limited has developed a rather nasty noise in 4WD (all modes). In 2HI a very slight low pitched hum can be heard at 50+ mph. Turn the selector to 4A (above 20 mph) and a noticeable roar starts. Sounds like I'm running 38" Super Swampers.

I changed the front diff oil and noticed some very slight amounts of metal. Don't know that it's enough to determine that a part has failed.

Is there any history of problems wtih transfer cases and/or front diffs?

We bought it new and it now has 90k miles. 4wd used very seldom. Occasional light snows here in WV along with the need to put it in 4wd every once in awhile when moving the horse trailer around on the farm.

Any ideas where to start? I was thinking of removing the front drive shaft, putting it in 4wd and see what happens. I'm thinking that if it still makes noise, then it's likely the transfer case. If not, then it's the front diff.

Wheel bearings and hubs all seem to be good (replaced one bearing and inspected the other) and it doesn't seem to pull in either direction in 4wd.

 

[Johnny Law]

Sorry I can't help with experience with this as I am new to the Expedition but removing the driveshaft and driving it will probably not necessarily pinpoint the problem with the transfer case as the hubs will lock and parts will be moving in the front differencial.

You will need to put it on a lift to be sure.

How are your front tires? Are they evenly worn? Evenly pressurized? Especially from left to right. Differences in diameter can put stresses on the front differential.

Johnny

 

[mindgame]

You may want to check your IWE solenoid if it needs replacing... Sounds like there is not enough vacuum going to the hub actuators to fully contract the hubs during driving..

 

[hysterwv]

I'll look into the IWE. Could have been an issue for some time. Unfortunately, it's now a front diff issue. Additional investigation this weekend and the noise is in the front diff. Looks like a tear down is in order.

 

[JUST4FUN]

Don't rule out the front hubs they go bad hum like you are talking about

 

[JUST4FUN]

After you drive it with the noise the diff should be too hot to touch
If not look and see if the hubs are real hot by touching the hub mounting bolts or the back side of the hub

 

[hysterwv]

After you drive it with the noise the diff should be too hot to touch
If not look and see if the hubs are real hot by touching the hub mounting bolts or the back side of the hub

I didn't do this, but...

I have access to a lift. Put it on the lift over the weekend and ran it. Used the old heater hose stethoscope and the noise is definitely coming from the front diff. This is my wife's daily driver and I might drive it a few hundred miles/year. She wouldn't notice noise or vibration unless it was dramatic. The front diff issue may be a result of a long-standing issue with the hubs that I didn't know about. I'm going to check vacuum on the 4wd system as well as check out the hubs.

Will tear into it today. Will post the findings....

 

[JUST4FUN]

I didn't do this, but...

I have access to a lift. Put it on the lift over the weekend and ran it. Used the old heater hose stethoscope and the noise is definitely coming from the front diff. This is my wife's daily driver and I might drive it a few hundred miles/year. She wouldn't notice noise or vibration unless it was dramatic. The front diff issue may be a result of a long-standing issue with the hubs that I didn't know about. I'm going to check vacuum on the 4wd system as well as check out the hubs.

Will tear into it today. Will post the findings....

yes,please post

 

[hysterwv]

Well, being what the job entails and my travel schedule for work, I took it to the dealer today (dealer principal is a friend and I only let one guy there work on it). I'm generally not a big fan of dealerships. Lorne (tech) torn it down a short bit ago and gave me a call. Bearings and caps pitted and worn. I'll get pics this evening or tomorrow afternoon. Ring, pinion, spider gears, etc are not worn such that they can't be reused.