I purchased a used 02 f250 cc 5.4L with 55,000 miles 3 months ago. It has 16" firestones with 30% tread left, non-limited slip rear-end and the tranny was serviced @ 50k according to the sticker under the hood. Beyond that I don't have any other history or maintance records. I've noticed that once I let off the gas after traveling @ highway speed, there's a whinning noise coming from the mid to back of the truck. On deceleration the noise continues until the truck comes to a stop. The noise is proportional to speed (early in deceleration, more noise). At cruising speed, I am not aware of any noise (whinning). It appears once I let off the gas. The noise is best described as a whinning growl.
I was wondering if a driveshaft u-joint could/would make such a noise. The reason I say this is because I've noticed a clunking noise in the rearend when I put it in reverse before backing out of the garage. I purchased a new u-joint but have yet to install, awaiting feedback from my fellow Ford loyalists. Any help, insite or related memos would be greatly appreciated. I do have some mechanical experience although lumber is more my bag (contractor by trade, Ford man by neccessity). Thanks in advance. Super.

 

When it's a real whine on deceleration, there's only two things it could be - the front pinion bearing, or the back of the teeth on the pinion and/or ring gears. Or, to a lesser extent, one of the side bearings that carry the differential (but you'd hear that at cruise...).

It might be a hanger bearing, but again, that would make noise at other times too, not just deceleration.

Remove the plug in the rear pumpkin where you would put gear oil - there should be a magnet on the plug that will catch pieces... pull it, and post back with what you find.

art k.

 

Art,
Thanks for the reply. I pulled the rear-end plug a week or so ago and found a silver/gray colored (not milky)lubricant with black specs which felt like graphite to the touch. The rear-end tag says to use synthetic lube, is synthetic lube gray/silver? Thanks. Awaiting further details.

bj s.
ps. would it be advantagous to replace the rear u-joint ? What are the tell-tell signs that the rear u-joint needs replacing? Sorry for my ignorance, I'm a contractor not a mechanic.

 

I removed the rear-end plug as you suggested and found that the silvery/gray lube was littered with minute shiny particles, you guessed it--metal. To further analyse the content, I wiped the magnetic plug off on a paper towel. This really made the shiny particles show up. My next question to anyone is how much metal filings is normal, if at all, at the rearend magnetic plug.? And is there a way to isolate which rearend bearing or gear is making the noise?

 

Some is normal, my brand new '01 with only a few K miles on it already had silver flakes on it, but the next 10K miles, nothing.

Some silver "gook" is OK - some small thin shavings are OK - if there are real good-sized chunks, that's bad...

Here's more on figuring out if it's the rear:

Is the pinion (front) seal leaking?
Jack up the rear wheels (both off the ground) - put tranny in neutral.
Turn the driveshaft by hand, do you feel any binding?
Is the pinion loose (in and out - or up and down)?
Start the motor, BE CAREFUL, and have someone listen without getting under the truck. Hit the gas, in high gear, let off - you should hear the whine and be able to somewhat locate it.

If you hear it coming from the rear of the truck, well, that's your answer. U-joints wouldn't make a whining on decel.

 

Thanks krewat,
Yesterday I jacked up the right rear only and rocked the wheel back and forth. In doing so, I could hear a clunk-clunk sound in the rear end as the wheel was rocked to and fro. Wondering if this "slop" is normal or if everything should be a little tighter. Also, as I originally posted, I said the rear-end noise is only on deceleration. Now, after having such an "ear" for rear-end noise, I've realized that a growling noise is evident as I drive slow and constant, particularly at around 5-15 mph. I don't necessarily notice the growling after 50+ mph, mainly do to traveling noise. I'll do the "jack up both wheel" thing and post back my findings. Any further info or ideas that might come to mind will be greatly appreciated. Sorry for any posting persistence on my part. I bought the extended warranty and want all the possibilities I can recieve when and if I need to take it in. It costs me $50.00 each time I take it in (warranty co-pay) and would like to limit the number of "trips" to solve the problem. I'm not a tight a**, but $50 bucks is $50. Nor am I one of "these guys". Woop "I" did it again. "Darn it". Stop "that". Ok I'm fine. Thanks for all your help Krewat, much appreciated.
BJ s. "superdutyconst" (just kiddin')

 

I've seen steady bearings (hanger bearing, center support bearing, whatever you want to call it) make noise just when decellerating.

 

Good point RacerGuy, I brought that up in my first post, but they usually make noise other times too, not just decel. Can't hurt to check though...

 

It's one of those "anything's possible" things.

 

I took the truck into the Ford shop this a.m. as instructed by the esp people and hears what they are telling the problem is:
all the gears in the rear-end are "out" and both front axle bearings as well. They are going to strip the rear-end so the esp inspector can take pictures of the damage. My esp is through Mechanical Breakdown, Inc. (MBP) of Lee's Summit, MO. The Ford service manager told me that MBP is considering putting in used parts from another rear-end if the damage is severe enough. They refer to these parts as "of like kind and quality." Has anyone had such parts installed? What's your IMO? As of now I have no truck and am really missing her. No Tauras yet either. Thanks

ps. Thanks for all you help and advice krewat and racerguy. Much appreciated. All I want for Christmas is my truck back. Almost like seperation of mother and child.
superdutyconst
__________________________________________________ ____
o2 f250 5.4L auto red tinted 4x4 (6' in the air)

 

I was afraid the gears would be toasted - I know one thing, for years whenever I blew the Dana 60 in the rear of my '74 highboy (from abuse, things obviously broke, they didn't wear out), I would go to a local truck junkyard, pick up a Dana 60 pumpkin (they would remove the axles and cut the pumpkin out with a torch), install it in my rear (no jokes, please ) and go on down the road.

If I were you, I would investigate if they really intend to install used parts, and if so, offer to put up money to get new if you have it to give, that is. Depending on how much they want to do it with new parts, you might be better off. But, depending on the skill of the dealer/mechanic, a good used broken-in rear with good oil in it will last longer than a badly-setup new set

Since the oil is most likely contaminated, that means wheel bearings need to be changed too... it's very easy for them to get a used rear complete, and install it in one big piece. Also, a lot easier than cleaning up the old rear and the possibility of leaving bad crud in it.

What was wrong with the front axles?

art k.

 

Sorry for lack of info on the front--- I meant front wheel bearings. Oh, did I mention the $1850.00 repair estimate. Anything over a $1000.00 requires a MBP inspector to review the repair before any work is done. It's funny you mention "abuse" on your old highboy. As I closely read the contract with my esp, nearly everything can be classified as abuse-- lack of or poor maintanece, breakdown caused by freezing, commercial business use (what I am--contractor), etc. I'm not one to abuse any vehicle, but you would think that an esp would/should cover repairs for above-average user, not just casual highway miles. I just think you have to remember that an esp is an insurance policy and with most insurance you have to almost fight for compensation. I don't remember getting a thank card from MBP when I gave them $2200.00 for the esp policy. Hey, that reminds me, I'll still have $350.00 credit with them. What am I bi**hing about?

Krewat, you were right on though with the rear-end issue, probably saved me from being stranded on side of the road. Or even worse the front wheel bearings going out. My family and I thank you. Take care.

super

ps. I'll leave the "in my rear" jokes for another post.

 

Yup, it IS like insurance. They offer to "settle" it by using used parts... that's legal jargon for agreeing to pay less than what it's really going to take to fix it.

You can hang tough and see where it gets you, but I think you might be hosed on the new vs used thing. But you could get them to at least replace the pinion seal and diff cover gasket... no knowing how long it was sitting around in the junkyard...