My 02 squeaks when I put the R400 tranny into reverse,(it sounds exactly like the bushings squeaking when you lower your tailgate). It only does this when you are pressing the go padal though. For example, if I am on a flat surface backing up and I let off the throttle, the squeaking will stop. It will increase or decrease depending on the speed of the truck and it sounds like it is coming from around the middle of the truck underneath the cab rear doors.

I did a quick search and come up with dry u-joints as a possible suspect but the fact that the noise comes and goes with the throttle has me stumped. Could it be the u-joints and that torque on the driveshaft has to be applied to make the noise?

Not sure if this is associated or not but my reverse sensor are operating sporadically also.

Thanks for any help!!

 

Dont know about the sensor being related, but that most definitely is bad/dry u joints. Not a bad job, but one that needs to be done from time to time.

 

Thanks Damon, if that's the case then that makes perfect sense since I just replaced the rear u-joints. That makes it the front u-joints, which is right in the area the sound is coming from.

Glad it's something simple and not the tranny!!

Thanks again!

 

Agreed....they usually squeak under load, not so much coasting, unless they're really bad

 

If not there, possibly the drive shaft carrier bearing is bad or the slip joint needs greased.

 

Shootin from the hip,it could be the shield on the rear brake calipers touching when you apply the peddle,giving it just a slight flex and causing one of them to touch the rotor.mine were bent and making a light scraping noise...

 

Thanks for the replies. I am going to crawl under it tomorrow and see what I can find.

 

Another shot from the hip but I'd say carrier bearing also, check first anyway. When my first one went out I heard a light rubber rubbing sound turning tight corners. Changed out this next one with the sound of a slight growling sound, going foward of course. About a 60.00 part.

 

Well I found the problem. It was the middle u-joint and that thing was definitely dry, so dry that it could not be moved by hand!

FYI, I went over the u-joints three different times while installed on the truck and you would have never noticed that they were bad. One must take the drive shaft down off the truck to thoroughly inspect the u-joints to know for sure.

As always, thanks for the help 7.3 guys!!!!
Now to find the growling from somewhere around the front end!!

 

Now dont get carried away, thats just the nature of the beast you have under the hood. Letting the old girl growl and snarl from time to time keeps her happy. haha

Anyway, glad you figured it out and got it fixed. This place is great.

 

Hey Mike, what did the growl sound like when your carrier bearing went out and where did the sound come from??

I inspected my carrier bearing and everything looked and moved right but I still have this hum noise coming from around the drivers front area. It sounds just like a bearing going out but I replaced the hub bearings as well as the front axle bearing inside the axle tube?

I guess I should start a new thread on this issue.

 

So true Damon, so true. Maybe I should spend the money on a better stereo so I can drown out the sounds!?!?

 

Hey Rob, the light growling sound I had I seemed to be coming from the rear area but it just goes to show you these sounds resonate thru the driveline so be wary. My carrier bearing looked good from the outside other than some slight more to me normal movement but it was shot, completely inside. I should have kept it and shot a pic of it but you know.

 

Man, now you have me kinda' wishing I would have just replaced it also. I held the drive shaft standing straight up in the air, grabbed the carrier bearing and spun it around the drive shaft. It made about 4-5 complete rotations around the shaft and sounded good so I figured I would just leave it.

 

Its one of those things, if you felt it was OK then your cool. With the driveshaft installed look at the up and down movement, all around really, besides the rubber flexing you want to see excessive play, what I was told. Mine seemed a bit much so.. Why I was leaning towards my carrier, this was the third, first one being stock that was replaced. If this one goes out I'm thinking I got other problems destroying these carriers.