Phantom Noise

jro909 · September 14, 2011

I've had this noise for a long long time, and just for peace of mind i want to figure out what it is...here are the specifics i can nail down

1) it only happens once, after the truck is started and i begin to drive, if i start it and drive then shut it off then do it all over ago..same noise

2) it sounds like a parking brake being released, seems to come from the rear of the truck(slip yoke?)

3) i kind of ruled out brakes seeing as they are about a month old

any ideas?

jdewolfe · September 14, 2011

ABS self test would be my guess? I'm sure others will chime in on this.

rog_ski · September 15, 2011

I've had this noise for a long long time, and just for peace of mind i want to figure out what it is...here are the specifics i can nail down

1) it only happens once, after the truck is started and i begin to drive, if i start it and drive then shut it off then do it all over ago..same noise

2) it sounds like a parking brake being released, seems to come from the rear of the truck(slip yoke?)

3) i kind of ruled out brakes seeing as they are about a month old

any ideas?

Curious to know if it happens differently depending on how you take off or if you take off up a hill or going down a hill.

If you leave on the flats with a lot of torque do you still get the noise, is it the same noise, more or less,
If you leave going up a hill do you get it the same,
If you take off going down a hill is it the same,
If you start to move and then let off the gas so the compression of the truck slows you down do you also get the noise or something similar when the engine starts to slow you down
You mentioned about shutting the truck off, what if you are driving, turn the truck off and while coasting turn it back on and pull it in gear do you still get it again.

I could see something in the drive line (universal - yoke) that has worn over time and it has to move and engauge before the truck actually starts to move if you get a different variation of the noise on the above. If the noise is the same for everything I would say that it is something that is engauging automatically.

Oh and that is just my 2 pennies

jro909 · September 15, 2011

i notice it the most if i say pull out a driveway then coast down a hill(with no pedal input)

it only happens once, and after the truck has moved a few feet...it sounds just like a parking brake being released on a hill

tanked_darren · September 15, 2011

These are the kinds of things that are not diagnosed well over the net, but...

like stated above it might be your u-joints, if its very minor, let it develop for now. IMO

jro909 · September 16, 2011

i'm not thinking u joints, because its been doing this for years...i also think it happens more when its colder outside

tanked_darren · September 16, 2011

Well as much as I hate "noises" as well. If it's done it for "years" I'd probably go with the old time advice of "if it ain't broke, don't fix it"

jro909 · September 16, 2011

it was more out of curiosity...with 120k on the ticker i'll accept a few noises out of a damn good truck

rog_ski · September 16, 2011

it was more out of curiosity...with 120k on the ticker i'll accept a few noises out of a damn good truck

I have 2 more cents to chuck at this one.

What about something in the suspension? Maybe a shock, spring bushing or maybe a grounding strap that moves or gets hooked on something when the truck finally gets moving.

I suspect you could find a decent back yard mechanic to go for a drive with you and he would tell you what it is.

KMGZ400 · September 16, 2011

hmmm are you sure its not the exhaust? my truck did this for a while.. the muffler would make a bang when the truck was off and sometimes driving

jblakeney · September 17, 2011

1. Remove 4 bolts from ubolt (and straps 2 from hanger, if you have one). Remove shaft. Clean and regrease......... Slip yoke (and slip joint at swing bearing, if you have the two piece shaft).....

2. Cushions on the lowest leaf springs at the ends of the leafs? Do you still have all 4?

3. Drum Brakes? I forget what year they swapped around and put the drums back on.....

4. Could just be nature of the beast..... My 95 Cougar I had when you took of hard it always made a noise that was hard to explain.... Kinda was a noise like no other..... Kinda sounded like a swishing sound mixed with a bump at the very end..... It did it the first day on the test drive with 2 miles on it.... Still does it till today. I drove a bunch of those cars before we got that one..... None of the other ones did.

Jbo

jro909 · September 17, 2011

1. Remove 4 bolts from ubolt (and straps 2 from hanger, if you have one). Remove shaft. Clean and regrease......... Slip yoke (and slip joint at swing bearing, if you have the two piece shaft).....

2. Cushions on the lowest leaf springs at the ends of the leafs? Do you still have all 4?

3. Drum Brakes? I forget what year they swapped around and put the drums back on.....

4. Could just be nature of the beast..... My 95 Cougar I had when you took of hard it always made a noise that was hard to explain.... Kinda was a noise like no other..... Kinda sounded like a swishing sound mixed with a bump at the very end..... It did it the first day on the test drive with 2 miles on it.... Still does it till today. I drove a bunch of those cars before we got that one..... None of the other ones did.

Jbo

1) i do have the dreaded slip yoke noise, but i kind of live with it...its been packed twice and i just gave up on having it repacked every year

2)i'm really not sure if they are their anymore, are you talking the round donut looking thing?

3) no they are disc all the way around, brand new rotors and pads

4) i was thinking that, i mean my interior creaks, my tailgate bangs on hard bumps...hell i love the truck all the same

as to the post about the exhaust, i guess its possible as i do have the issue with the vibrating exhaust that their was a tps out about