Mystery Growl

[199380]

I have an issue with my Land Cruiser that has me stumped. Any input or suggestions are appreciated.

1996 locked 227,000 miles

Front end has been serviced with new spindle bushings and plenty of Moly grease in the knuckles/spindles. (complete knuckle rebuild, swapped birfields, new wheel bearings)

All oil levels are good


Problem:
Makes an intermittent growling noise most noticeable on the interstate around 70 MPH. It makes the noise both with the CD Locked and Unlocked.

What as been done:

Pulled the front drive shaft, locked center diff, and went for a drive. The noise went away.

Tried another front drive shaft and the noise remained.

Put the cruiser on stands in the front, took the rear drive shaft out, took the front tires off, locked center diff. I can make the noise with the cruiser in the shop. With a mechanics stethoscope it sounds like the transfer case is making a ruckus. Put in my spare t-case and the noise remains.

Front pinion is tight. The bearings were inspected and appear to have normal wear. No pitting or roughness to the rollers or races. Carrier bearings look fine.

Does not make the noise with the CD locked and no drive shafts in.

It really sounds like it is in the t-case, but I have trouble believing two cases are making the exact same noise.

Thanks in advance.

 

[97FZJ80]

Sounds weird but i had a growl too. Couldnt figure it out. Drove through some water and when i got out to check there was water bubbling from the front of my muffler right behind the t-case. I put some insulated metal tape on it and test drove it. Growl went away. I need a new muffler now. Odd but saved me a bunch of money of replacing a bunch of crap. Mine only growled at highway speeds also.

 

[Hoosier Daddy]

Was the second front driveshaft new or used? Any lift?

 

[Kernal]

Is the noise heard from outside the truck when on stands or just when inside the cabin? Did both transfer cases sound the same either with a stethoscope or not?

 

[199380]

Thanks for the activity.

I won't rule out the muffler but it seems to be a bearing growl.

It was my spare used drive shaft. Both shafts seem to have good joints and tight splines. It has a FOR lift with caster plates.

The noise is heard inside the cabin and outside. The noise was identical after swapping the transfer case. It sounds like it is coming from the passenger side when sitting inside the cabin.

 

[Hoosier Daddy]

Sounds like a double cardan front driveshaft is what you need.

 

[199380]

I guess it being an intermittent noise led me away from the drive shaft.

It does makes sense that the incorrect geometry of the u-joints could be causing the growl and it occurs when the "harmonics align"

 

[mbarela]

Did you every figure out what was causing the growl. I have run into the same thing after installing an OME 3" lift and have been chasing the sound. Any help would be much appreciated. Thank you....

 

[Delancy]

Sounds like a double cardan front driveshaft is what you need.

Check all the driveline angles before buying a DC shaft. It's, by no means, a cure all for vibes.

 

[dswick]

I have the same noise but only on deceleration. Have taken front drive shaft off and noise still there. It is there during coasting both in gear and out of gear. I have not tried too hard but seems to go away when in diff-L.

I have been driving it this way for 10k and it is getting worse but not sure what to fix...HELP

 

[BILT4ME]

I have the same noise but only on deceleration. Have taken front drive shaft off and noise still there. It is there during coasting both in gear and out of gear. I have not tried too hard but seems to go away when in diff-L.

I have been driving it this way for 10k and it is getting worse but not sure what to fix...HELP

What year, Make of your truck? There are slight differences that can make all the difference.
Have you checked your REAR DS? (install the front DS, take out the rear (lock your CDL)

 

[SUMMIT CRUISERS]

A bad u-joint will create a growl while decelerating. You must remove both drive shafts to test. Test each u-joint by rotating it on both axis. If one rotates not perfectly smooth, that's the one that needs changed.

 

[dswick]

I finally found the noise....after replacing the transfer case and it did not solve the issue i had the pinion angle checked and it was fine --- however the drive shaft was out of tune and balance --- no more growling

 

[BillyGoatMTB]

I have been chasing the same issue. After a year took her to a pro driveshaft place in Sacramento. The guy there Al took the angles himself. I handed over my brand new never installed factory front shaft and he made me up a DC.

The deceleration growl got much better but it's still there, right between acceleration and deceleration. Keeping the shaft lubed like every 1k seems to help but that's just masking the issue.

I called and plan to bring her in, Al said he would now check caster next.

Did anyone else find a solution? Looking for other ideas to check.