Another Front End Noise Diagnosis Thread.....

[Cruiser4Lyfe]

'Noise is most noticeable on deceleration from high speed. Not throttle dependent. Makes less noise on acceleration than deceleration'

Does your 80 Have a lift kit? Mine did the exact same thing your describing after I installed a 2.5 inch lift kit. What I didn't do immediately at the time of the lift kit was install the supplied caster bushings. Once the bushings were installed in the control arms the vibration and noise went away. Was anything moved or disturbed in that area?

My .02 cents

CB

Yes, I installed an OME 2.5” kit and the supplied Castor correction bushings back in November.

 

[shocktower]

OK, YES, it can.

Detail:
I rebuilt the front axle with all Toyota seals, Kits from Cruiser Parts. I was meticulous about cleaning, aligning, fish-scaling everything. This is NOT my first rodeo, as I have been wrenching for 45 years. Grew up on a farm, rebuilt my first engine at 10YO. I built a 4WD Chevy for a 4-H project, so I know what to do.

Rebuilt everything, new bearings, new seals, new rotors, new axles (RCV), new brakes, new calipers. Lubed all parts before assembly. Used a torque wrench on EVERYTHING. Moly in the knuckles, Red-N-Tacky on wheel bearings 85-90 in diff.

Started DD the truck and within 5000 miles, I had Birf Soup on the RF knuckle. Everything was new, so it wasn't a matter of whether the seal was aligned in a groove. I had no trouble stabbing the axles, so I had no concerns with the inner seals from an assembly standpoint. Folks here advised to stay away from Marlin seal for a DD and I did. Only Toyota seals in there.

I checked out the axle vent housing and it was pretty cruddy, so I took it off and cleaned it. I removed the hose and it was clogged. I removed the fitting from the axle housing and I had to use a dental pick to remove the solidified gear oil and grime from the PO. Then I reinstalled the fitting, added about 5 ft of 1/4" fuel hose and a fuel filter as a vent and draped it up over the brake booster.

I sucked out the birf soup from the knuckle, and changed the differential oil.

The problem has gone away and never returned in 65K miles.

With the axle vent clogged: On a long drive, the axle housing would heat up and pressurize. The pressure would force the gear oil past the seal , into the Birf. As it cooled, the housing would go to a vacuum and suck the gear oil/grease mixture back into the housing creating Birf soup in both the knuckle and the differential.

Since I cleaned the fitting and installed the long vent hose and fuel filter for the vent, I have not had Birf soup again in 65K miles. I have never opened up the knuckles again.

So, yes, it CAN, and will happen if the conditions are right.

Only after the seal fails and the gear oil flows into knuckles, but grease never migrates by osmosis, it had to have a bit of mixing, and it can happen without the vent clogging too . I just started doing this two weeks ago so I'm learning new stuff

 

[UncleLDP]

So I need a little help from those that know more than me about land cruisers... My cruiser is a 1994 80 series with 126,000 miles on it. I have a slight front end moan that has been happening for about the last 1,500 or so miles. It’s not super noticeable to anyone but me, but I can hear it slightly and it’s more of a vibration coming through the steering wheel and through the driver side floorboard (my feet can feel it). It’s not like a “I’m going to be calling AAA any minute on the side of the road” noise; more like a nuisance and a long term reliability concern.

Here’s the fact pattern regarding this noise:

1. Front drive shaft was replaced with a brand new one just a week or two ago. Rear U joints were also replaced.
2. Front Wheel bearings and spindles were replaced over the weekend. I used new 95-97 style OEM Toyota spindles with the needle bearings instead of the brass bushing. Used new Koyo wheel bearings and Mobil 1 red synthetic grease. None of this changed the noise.
3. Did a full front Knuckle rebuild in December. Prior owner (friend of mine with no business owning an old vehicle) I suspect drove it for 30-50,000 miles with the inner axle seals blown out. Birfields looked fine and didn’t make any clicking noise, but all the grease had migrated to the differential and was a nasty sludge.
4. I did not notice the aforementioned noise until AFTER I rebuilt the front axle and did several drain and fills to flush out the migrated grease. This was also when the u-joints were going south so at the time I figured that was the noise.
5. Pulled the new front drive shaft and locked the transfer case (triple locked cruiser) and went for a drive. If anything the noise seemed louder without the front shaft.
6. Noise seems load dependent. It occurs at a lower speed if I am driving into a head wind (50 mph) than if I am driving with a tail wind (65-70 mph).
7. Noise is most noticeable on deceleration from high speed. Not throttle dependent. Makes less noise on acceleration than deceleration.
8. There is no leaking from front diff input shaft at all, and it seems tight .
9. The noise was also present while coasting down hill with both the transfer case and the transmission in neutral.

I just bought this thing in October, and it’s in pretty good shape now thanks to the wealth of information this forum has provided. I am trying to diagnose this noise pretty aggressively because I would like to drive it from Texas to California and back at the end of June and I want to make sure it’s nothing critical.

Is this just part of the territory with a full time 4wd vehicle or do I have a diff problem that needs to be taken care of ASAP? Thanks for all the assistance!! This forum is an incredible resource.

Hello- just read through this thread. I'm having the exact same issue. I just did a knuckle rebuild and wheel bearing replacement rotors and pads. Did you have any luck with the new torque specs that were suggested in this thread?

 

[Cruiser4Lyfe]

Hello- just read through this thread. I'm having the exact same issue. I just did a knuckle rebuild and wheel bearing replacement rotors and pads. Did you have any luck with the new torque specs that were suggested in this thread?

I think what it ended up being was the rear drive shaft was assembled slightly out of phase when the rear u-joints were replaced. I pulled the halves apart and re-assembled correctly and it was dramatically quieter.

The wheel bearings definitely loosened up after using the factory preload method; I’m still no professional, but 25 ft lbs seemed to be much more suitable for the torque of the spindle nuts and wheel bearings.

 

[UncleLDP]

Got it thanks. I've never dealt with a ujoint or drive shaft. Any tips or links that you might have would be appreciated. I'm going to try the pre load first but I think the bearings are ok.
Thanks

 

[retrofive]

I think what it ended up being was the rear drive shaft was assembled slightly out of phase when the rear u-joints were replaced. I pulled the halves apart and re-assembled correctly and it was dramatically quieter.

The wheel bearings definitely loosened up after using the factory preload method; I’m still no professional, but 25 ft lbs seemed to be much more suitable for the torque of the spindle nuts and wheel bearings.

This is one area the FSM is wrong. Use member Tools method.

 

[UncleLDP]

I’m

This is one area the FSM is wrong. Use member Tools method.

? Not sure I'm understanding...

 

[retrofive]

I’m
? Not sure I'm understanding...

Step-by-Step Bearing Preload Post?

Any Gold-Standard post on this, ideally with pics? Thanks!

forum.ih8mud.com

 

[UncleLDP]

Step-by-Step Bearing Preload Post?

Any Gold-Standard post on this, ideally with pics? Thanks!

forum.ih8mud.com

OK, I gotchya . I'm going to re-torque this weekend but I'm leaning towards a drive shaft issue as my noise comes on deceleration more than any other time. Not sure if this DS has ever been pulled before I got it so I'll just inspect and go from there. Thank you

 

[retrofive]

OK, I gotchya . I'm going to re-torque this weekend but I'm leaning towards a drive shaft issue as my noise comes on deceleration more than any other time. Not sure if this DS has ever been pulled before I got it so I'll just inspect and go from there. Thank you

Ya, not sure about that. Was just trying to say on the preload, the FSM in that particular case isnt the best method and believe has the wrong info.

 

[retrofive]

OK, I gotchya . I'm going to re-torque this weekend but I'm leaning towards a drive shaft issue as my noise comes on deceleration more than any other time. Not sure if this DS has ever been pulled before I got it so I'll just inspect and go from there. Thank you

My decel noise ended up being the ujoints, and check the phasing. That helped the most, but had I kept my 80 I would have put a DC in. Sorry think that was all mentioned before earlier, I skimmed the beginning of the thread and went to the last post.