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mod5csi
05-31-2012, 09:51 AM
Good Morning All,

I originally posted over on IH8MUD asking about a sound from what I believe was the front end. I have copied and pasted the IH8MUD post below. It was recommended I post here to see if anyone would be willing to meet up and take a listen to the sound I am having. I live in Parker at E470 and Parker Road, and I work in Aurora at Buckley AFB. Or if there is a good 80 series / Toyota / 4x4 shop around, please let me know.

Anyway, thanks in advance for your thoughts. Below is my IH8MUD post:

I hate making new threads, I have always been able to find the info I need by searching. But my Search-Fu has failed me this time.

I have a noise coming from the front end. The noise is a wa wa wa wa wa wuh wuh wuh wuh wuh sound. (more like a propeller or flat spotted tire than a baby crying wah wah sound). Not metallic, not grinding, not squealing. The volume and frequency increase with road speed and seems to peak around 40 mph. After that either wind noise drowns it out or it is going away (which I doubt). Also, the noise is only while on the power. Off throttle I do not hear it at all. And I only hear it with the windows up. I dont hear it with the windows down, and I dont hear it while driving next to it with someone else driving the truck. Its almost like a resonance more than an actual noise (if that makes sense).

1996 Lexus LX450, 190k miles, CDL, but no lockers, well maintained at Lexus for the 140k miles, no records after that.

Some diagnostics and work I have already done:

1. Removed the front driveshaft, locked the CDL; noise went away completely
2. I had the front driveshaft, rebuilt with new Toyota U-Joints and balanced out of phase at Rocky Mountain Driveline in Denver, re-installed and noise is still present.
3. I rebuilt the front end, repacked birfs, swapped sides, installed new trunion bearings, wheel bearings, axle seals, and brakes. Noise is still present.

So now I am leaning toward the differential. But before I tear into that and have to redo all the birf work I just did I wanted to check here.

Thoughts?

J Kimmel
05-31-2012, 10:19 AM
bearing in your diff maybe

mod5csi
05-31-2012, 10:26 AM
I should have mentioned. I am leaning towards replacing the pinion bearing before tearing into the diff. If replacing the pinion bearing is even doable without removing the entire diff from the truck. The service manual is not clear on this.

DaveInDenver
05-31-2012, 10:29 AM
I had a similar sound that I thought was my transfer case output bearing. I couldn't tell for certain if it was in the diff or axle bearings, but it went away when I swapped rear axles. My guess is the pinion bearing was the culprit.

Rzeppa
06-01-2012, 01:54 PM
I should have mentioned. I am leaning towards replacing the pinion bearing before tearing into the diff. If replacing the pinion bearing is even doable without removing the entire diff from the truck. The service manual is not clear on this.

You have to take the diff off and apart to change the pinion bearing, and yes, after reading all the stuff you've done that sounds like the most likely culprit. And of course to get the diff off you have to slide the axles out.

But...try the simple stuff first. Make sure your pinion nut is tight. I had a vibration in the rear of my 60 and discovered that the nut was loose and had never been staked. I tightened it and staked it and my problem disappeared.

mod5csi
06-01-2012, 02:04 PM
Thanks guys,

I will try tightening the pinion nut.

I picked up a stethoscope today and plan on crawling under there and listening while its in gear (and safely on jack stands).

I have done some further diagnostics based on some feedback.

1) out on a dirt road I locked the CDL in 4hi and 4lo and verified the noise is still there. I was hoping to rule out or confirm the T-Case but I still cant.

2) the noise is present outside the truck, driving next to a brick wall I was able to hear the echo off the wall (great way to diagnose wheel bearings also).

So really I am in no better place than before, but I will let you know what I come up with with the stethoscope.

rockrod
06-01-2012, 03:46 PM
Is the noise fast like at driveshaft speed or is it slower in relation to tire speed? I had a front pinion bearing go out and it was a whirring noise while driving that increased with speed. Removing the front shaft had no effect and I eventually jacked the front of the truck off the ground and spun the gears by hand with the front shaft out. Slee rebuilt the front diff for me once I knew it was a bearing.

I am in the pinery and will be more than happy to have a look.

Corey

mod5csi
06-01-2012, 04:20 PM
Is the noise fast like at driveshaft speed or is it slower in relation to tire speed? I had a front pinion bearing go out and it was a whirring noise while driving that increased with speed. Removing the front shaft had no effect and I eventually jacked the front of the truck off the ground and spun the gears by hand with the front shaft out. Slee rebuilt the front diff for me once I knew it was a bearing.

I am in the pinery and will be more than happy to have a look.

Corey

Thanks Corey,

I will PM you after I get under there and still cant figure it out. I followed your 5.3 build on IH8MUD with a lot of interest BTW. Sounds like fun now.

The volume and frequency both seem to build as road speed increases. Whether its tire speed or driveshaft speed I couldnt say. But it seems slower than what I think the DS is spinning. And the noise went away completely when I removed the front DS.

I just had a thought but Im not sure it will get me anywhere... The DS and therefore the pinion and its bearing should be spinning at the engine RPM when in 3rd gear (1:1 ratio), correct? And then it gets reduced and slowed down by the ring gear and then sent out to the wheels by the spider gears.

I will try a couple things omw home from work...

60wag
06-02-2012, 07:05 AM
I had a noise not unlike what you describe in my rear diff. It turned out to be a damaged carrier - the thing the ring gear bolts to. It may be have been due to an accident from the previous owner. If you do end up removing the diff, examine the entire thing, not just the bearings.

sleeoffroad
06-02-2012, 03:23 PM
Lift Height? Mods to the suspension?

mod5csi
06-02-2012, 03:38 PM
Appears to be stock height. I bought it with 33" tires and steel 16" wheels already on it. No other mods a far as I can tell.

I got under it with all 4 wheels spinning in the air. I verified it is coming from the front diff. The noise peaks at 30 mph and tapers off after that. But it is always there to some degree. Verified with a stethoscope.

The pinion nut has it's lock ring, so im not going to mess with that until I get a new one to install. I tried wiggling the flange up, down, left, right, and in and out and there is no excess movement. There is about 25 of play when spinning the pinion before it meets resistance.

For now I have removed the DS again. And will start shopping a rebuilt front diff, or parts to DIY.

rockrod
06-02-2012, 05:26 PM
sounds like a bearing or possibly ring and pinion... Is this an elocked truck? Slee rebuilt mine for a decent price, but reused the ring and pinion. this happened in July last summer and it's been fine since, even with the V8 motor.

mod5csi
06-02-2012, 05:29 PM
Not e-locked.

Im pretty sure I'm going to commit myself to rebuilding it. If anyone has a spare let me know.

TIMZTOY
06-03-2012, 07:38 PM
when you lifted it up to listen with a stetascope. did you check the t-case out put bearings ?
reasion i ask is im confused.
you stated that you pulled the front drive shaft and locked the cender diff..
and the noise went away..
did you do them at the same time ? if so, locking the center diff wont matter with the shaft off..
tip: when stethascope and car lifed.. prob all the bearing points. of the diff..
pinion, both outer axle bearings.. and diffrent spots around the pumpkin.. youll hear the noise everywere. but should be obvious when you find the source..
youll even hear a t-case bearing at the axle's, but wont be obviouslly loud and detailed

mod5csi
06-04-2012, 08:35 AM
Im not sure I follow what youre asking.

With the DS in and CDL locked and not locked there was no noise at the T-Case, and the noise was all over the front diff. Listening through the housing I could not pinpoint, the noise at the pinion, left or right side.

With the DS out I do not hear any noise, inside the car, outside the car, or under the car.

I need to review my differential workings but now I am wondering... What is not spinning with the DS out? Seems to me if the truck is rolling and the birfs are installed everything is spinning as if the DS were in. But I do not hear the noise. So the noise must have been resonating through the DS, and is likely still there, I just cant hear it. Which means I am still causing wear and damage to whatever component it is.

rockrod
06-04-2012, 09:22 AM
This leads me to think you have a ring and pinion problem. With the shaft in the gears are loaded which results in the noise. With the shaft out the gears are not loaded so the noise is reduced to the point that you can't hear it. A bearing would make the noise regardless.

nakman
06-04-2012, 09:49 AM
This leads me to think you have a ring and pinion problem. With the shaft in the gears are loaded which results in the noise. With the shaft out the gears are not loaded so the noise is reduced to the point that you can't hear it. A bearing would make the noise regardless.

Agree with that theory. You're also using the other sides of those gears with the DS off, since your load is now coming from the axles, rather than from the pinion. IOW, your pinion is the last to get it, rather than the first.

Air Randy
06-04-2012, 09:53 AM
This leads me to think you have a ring and pinion problem. With the shaft in the gears are loaded which results in the noise. With the shaft out the gears are not loaded so the noise is reduced to the point that you can't hear it. A bearing would make the noise regardless.

It's probably one of the side carrier bearings. Usually if the R&P is bad the noise will not go away with speed. A side bearing will make the growling noise you describe, and having the DS out will unload the side thrust against that bearing.

mod5csi
06-04-2012, 10:08 AM
Thanks again guys.

I am inclined to pull the diff now. I will check back in when I get it out. Maybe it will be something obvious once I get it out.

Im hoping to find a shoe lace untied, or something equally mundane :o

Air Randy
06-05-2012, 09:35 AM
Thanks again guys.

I am inclined to pull the diff now. I will check back in when I get it out. Maybe it will be something obvious once I get it out.

Im hoping to find a shoe lace untied, or something equally mundane :o

If you pull it out you should rebuild it no matter what you find. Buying the required bearings & seals is relatively low cost. Find someone in the club with a bearing press and the experience to help you and it's a straight forward Saturday afternoon type of job.

TIMZTOY
06-05-2012, 11:02 PM
If you pull it out you should rebuild it no matter what you find. Buying the required bearings & seals is relatively low cost. Find someone in the club with a bearing press and the experience to help you and it's a straight forward Saturday afternoon type of job.

agreed..