My truck sounds like a school bus any ideas?

[84 400]

Well I have done some recent work to my 77 k10 and it sounds very loud going down the road. I can't feel any vibes tho so I guess that is a good thing? My father is sold that it is the font end but it is no longer turning... Plus it has new wheel bearings.

Recent work includes
New inner/ outter wheel bearings and races.
New super winch quarter turns
Parttime shaft kit in the np203
New front brake calipers

My front brakes are no longer dragging and the hubs are not getting hot which is great (old calipers) but the noise has me concerned. IT does have a 4 inch lift and 34 tsl bias ply swampers. I know Swampers are supposed to make noise and they do but this sounds more like a gear wine noise and less like tires.

The noise starts at sound 15 mph. Then quiets down but is till there.

Should i try lowering the T case with the factory spacers?
Any other ideas to help me diagnose the problem?

We took it on the high way for the first time on Saturday and it was very loud but no wobbles or vibes so that was good. I mounted the tires myself and they have not been ballenced.

Thanks for any help.

[rwolf9653]

I cant remember if those have the two piece drive shaft or not, but it could be your carrier bearing. I had an 81 2wd that had a similar problem, and the carrier bearing was the culprit.

[84 400]

It is a 1 peice shaft. Good thought

[dammitmitchell]

swampers are ridiculously loud....

[DirtyLarry]

You’re not giving us much to work with here….

Another item to look at is a seized fan clutch, as they can be loud like a school bus. More of a roar noise though.

Is your noise a whine, hum, roar, click, meow, or ???

[72 CustomCamper]

Do you have another set of tires you can try to help rule out the Swampers?


Chuck

[84 400]

okay I will try to give as much info as I can. I know it is gonna be hard to answer as this is over the internet and these are easier to diagnose in person.

It starts making the noise at around 15 or so mph. It is audible speeding up and slowing down on and off the gas. My first thought was Drive shaft angles because I lifted the truck.. However it is only a 4 inch lift and the angles don't look too bad to me. its a low noise kinda like the sounds straight cut gears make. I guess a low growling noise. The tires are loud but this seems to be a bit lower tone then the tire noise. my buddy had swampers on his xj so i know the noise they make but I may try throwing my 31's on just to be sure it is not the tires.

[special-K]

Anything making noise in the drivetrain or front end should produce a vibration or something you can feel.It would be a harmonic issue which is what would produce the sound.I instantly envisioned a fan sound like Larry.Maybe it`s the association with a school bus.I hear the fan and the tires hum.Inside a bus is a racket of tin.Nothing mechanical sounds,just a big tin can.The other sound is the diesel motor.You say it changes with rpm?Not also with wheel speed?That would be under the hood.Is there a fan clutch or a flex fan?I`ve run flex fans and always thought my truck sounded like a bus or delivery truck.They both are stop and go vehicles and engage the fan more.

[rwolf9653]

Just for process of elimination, take the fan off and run it down the street real quick to see if that makes it any better.
Be sure to put the nuts back on the pulley though.

[special-K]

You say it sounds like a school bus going down the road?I know the sound you describe.It sound like a bunch of kids screaming and yelling and throwing things,right?J/K!

I reread you post.I`m thinking it could very well be the 203.Either something about the conversion or something is bound/too tight?I guess Ive heard a TH350 wine before.

[Benelli]

I'm leaning twards tires.

My friend bought a truck that had a front axle gear fluid leak and it sounded like a rolling gear set going down the road driving it home.