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timmbuck2
07-19-2010, 11:09 AM
So Amber is heading to the east coast for a few weeks, and driving the 80 with our 2 girls. Yes, she is crazy, but this is not about that. :) I am doing a ton of maintenance to prepare her 80 for the trip, and I am stuck figuring out a front end noise. At very low speeds, under 10mph, the front wheels make a light screeching scraping sound, almost like the brake pads are worn out, but I pulled both front wheels and the pads are good. Any clues as to what may be going on? Worst case, I can send her in my 80, but with bigger tires and a lift will cause worse gas mileage, and also means no wheeling for me while she is gone! (other than the 40's only run...)

Thanks all!

Timm

DaveInDenver
07-19-2010, 12:56 PM
Going straight, does the noise change or go away if you turn the wheel gently to one or both sides? If it truly sounds like brake sounds that might indicate the wheel bearings are loose, letting the rotor move a little between the pads.

RockRunner
07-19-2010, 03:35 PM
If you push on the brake peddle barely does the sound go away?

timmbuck2
07-19-2010, 03:53 PM
Going straight, does the noise change or go away if you turn the wheel gently to one or both sides? If it truly sounds like brake sounds that might indicate the wheel bearings are loose, letting the rotor move a little between the pads.

Not sure, will check tonight.

If you push on the brake peddle barely does the sound go away?

The brake pedal seems to not affect the noise at all

Jacket
07-19-2010, 04:06 PM
Are there any markings on the rotor itself that would indicate the pad is rubbing in a non-uniform way? Does the sound increase/decrease with speed?

I like Dave's wheel bearing guess, or in my case a similar noise was a seized caliper piston rubbing on the rotor.

nakman
07-19-2010, 04:07 PM
How about a bent dust shield? A rock between the rotor and dust shield?

TIMZTOY
07-20-2010, 02:00 PM
Jack up all 4 corners and have her go 10mph while your under it listening!!
It might be a backing plate. If its rotational like A wheel bearing The noise will increase with speed and typically do it all the time. Not just at 10. Same with backing plate. And knowing women it's been doing this for months. And she never said anything :lmao:

timmbuck2
07-22-2010, 09:02 AM
ok, had some time to work on it last night, still not sure what is going on

took some time to drive it, and the noise is more like a squeaky spring than anything at slow speeds. from 5-15mph is becomes a rotational sound that increases with speed, and is faster than the wheels, so I am leaning towards a driveshaft issue.

jacked up the front end, did the wheel bearing test (grabeed it at 12 o'clock and 6 o'clock and pushed and pulled) and there was little to no movement. I spun the wheels as quick as I could, and there was NO noise anywhere. I pulled the wheels and looked at the brakes again, and all looked good. spun the wheels again and listened very closely to the brake pads and barely heard anything at all.

lubed up both driveshafts, did not seem to affect the noise at all. except the noise is not here in reverse, or is much much quieter. not sure if this happened because of the driveshaft lube or not, Amber said she first noticed the noise in reverse.

so now what? anybody had a squeaky driveshaft before? (yeah, that will end up in a sig somewhere...) I might get a center diff switch from Slee and then yank the front driveshaft to see if it is the issue. might not be a bad idea to leave it off anyway if she is going to be putting 4000+ miles on the truck in the next month...

thanks everyone...

TIMZTOY
07-22-2010, 10:23 AM
jack up all 4 tires off the ground, and have her drive 5-15 mph and you crawl under the car listening for the noise. youll find it !!!!! we do this at work all the time

Hulk
07-22-2010, 10:46 AM
jack up all 4 tires off the ground, and have her drive 5-15 mph and you crawl under the car listening for the noise. youll find it !!!!! we do this at work all the time

Man, that scares me to death. I bet you guys have a lift that would prevent the truck from falling no matter what. Jack stands don't seem quite as reliable, especially when you're putting all that torque on them.

Another thought: pull 1 driveshaft, engage center diff, drive it. Still hear the noise? Put the first one back in, pull the second one. If the noise goes away, you have found the culprit.

timmbuck2
07-22-2010, 10:55 AM
man, That Scares Me To Death. I Bet You Guys Have A Lift That Would Prevent The Truck From Falling No Matter What. Jack Stands Don't Seem Quite As Reliable, Especially When You're Putting All That Torque On Them.



X2!!!!!

timmbuck2
07-22-2010, 12:21 PM
from a guy on MUD:

is it a speedo noise? I have a strange sqeak on mine too, havent figured it out yet.

I was suspecting my speed sensor on the tranny

TIMZTOY
07-22-2010, 12:32 PM
Thats what the break peddle is for. Your not going to be flooring it from a stop you just rolling it to it. There Isn't any torque on it like this unless our being foolish. And we use the alignment rack which is the same thing as safety jacks. Because you need the suspention loaded. To mimic driving on the road. If your squeamish face the truck towards the street, jack it up, and drive it to 40 or so b4 getting under it at 15mph. To get a feal for how it reacts on stands. You can also shake and rock the living s**t out of It motor off to see if its tipsy. I assure you its not.

Air Randy
07-22-2010, 04:03 PM
squeeky drive shaft could = bad u joint

timmbuck2
07-22-2010, 04:06 PM
squeeky drive shaft could = bad u joint

I am leaning towards this...

So I can pull the front drive shaft as long as I keep it in 4 wheel low, right? Don't need to go very fast to see if it is still making the noise...just would need the center diff lock switch if I was going to keep the driveshaft off...right?

Hulk
07-22-2010, 04:23 PM
I am leaning towards this...

So I can pull the front drive shaft as long as I keep it in 4 wheel low, right? Don't need to go very fast to see if it is still making the noise...just would need the center diff lock switch if I was going to keep the driveshaft off...right?

Right. If you don't have a CDL switch, putting it in Low will engage it.

corsair23
07-22-2010, 04:26 PM
I am leaning towards this...

So I can pull the front drive shaft as long as I keep it in 4 wheel low, right? Don't need to go very fast to see if it is still making the noise...just would need the center diff lock switch if I was going to keep the driveshaft off...right?

For testing purposes, straight line, yeah shifting into low would work...

5 mins of work and you could use the hazard switch as your CDL switch (I think you need to do some trimming though) or the other route is to shift into low range to lock the center diff, pull the fuse, and then shift back into high. I think I would do this and avoid any potential for more noise being introduced by the center diff being in low.

timmbuck2
07-22-2010, 04:27 PM
For testing purposes, straight line, yeah shifting into low would work...

5 mins of work and you could use the hazard switch as your CDL switch (I think you need to do some trimming though) or the other route is to shift into low range to lock the center diff, pull the fuse, and then shift back into high. I think I would do the later and avoid any potential for more noise being introduced by the center diff being in low.

which fuse?

5 minute fixes are very rarely 5 minutes for me. :)

nakman
07-22-2010, 04:28 PM
You should also be able to just use the hazard switch, if you want to stay in high range. I know many have opted to get a second hazard switch for their CDL, since they're cheaper than a CDL switch.


edit: dang, you guys are quick!!! beaten by Corsair..

corsair23
07-22-2010, 04:46 PM
which fuse?

5 minute fixes are very rarely 5 minutes for me. :)

Me either :hill: - Call it a 30 min swap

As for the fuse, looks like it is the big 30a fuse, #14 in the panel by your left knee

FZJ80 Fuse Chart (http://homepage.mac.com/dfmorse/FuseChart3.5.1/page2/F13.html) - This is a chart for a '94 but should be similar/same I'm thinking

Nay
07-23-2010, 09:57 PM
Pull the driveshaft and take it to a shop. You can't diagnose this on the web.

If the driveshaft is fine, tell :Princess: not to drive 5-15 mph on her 4K trip to the east coast and she'll be fine and will actually get there as well :lmao:

We also do this trip every year (not this year, thankfully). Freaking long drive in a minivan with dual DVDs, that's death in an 80. :bowdown:

timmbuck2
07-26-2010, 09:18 AM
pulled the driveshaft, and allllll the noises went away. swapped in the recently rebuilt driveshaft from my 80 and her truck was good to go. So nice to have a "spare parts" truck lying around. :rolleyes: Never had a driveshaft on an 80 just make a ton of noise with no vibrations or other symptoms, but now I know. Thanks to all for your advice.

Timm