97 FZJ80, unsettling noise (3 Viewers)

[ghostofamerica]

Hi mud h8ters,
I've been hearing a noise. Awful hard to diagnose a problem without hearing it, but can't hurt to ask.
The sound is a binding sound, but not a clicking. More like a tapping when rolling forward. Hard to tell if noise persists under strong acceleration, because of the engine. It's not a loud noise when moving forward. Like something is misaligned that slaps in forward, but drags in reverse (or with significant drag in reverse direction as in when rolling forward downhill).
Sound is not affected by turning, so maybe that rules out the Birfs, I am not an expert.

Interesting things that do affect the noise:
Reverse gear...sound gets louder and is more of a binding sound.
4WD Low when rolling forward downhill...noise gets louder, binding sounds more popping, like rocks crunching under tires popping.
When going forward uphill...noise disappears, maybe not entirely, but almost.
When going forward uphill in 4WD Low, noise disappears, maybe even more than without low.

Have checked:
for loose "things"
differential fluid

Aand, noise is getting worse. One week of school left for the semester. Would love to not get gutted on road before then.

Recent work:
Wheel seals all round, brake pads n rotors all round, previous owner claimed to have had "front end rebuilt."

I've owned it for about three months.

And today a guy with a pickup and an enormous flatbed sideswiped me, so there are holes in the sheet metal now too, but I can diagnose that.

Thank you for reading,
David

 

[Fj80oregon]

Have you checked your fluid level on the birfs?

 

[robnicko]

does it sound like the front or back where the noise is coming from?

remove the front drive shaft and lock the centre diff and test as RWD only, this will tell you whether its front or back

id be looking at uni's (F & R) or even the drive shaft slip yoke could be binding up if theres an associated vibration

 

[Kernal]

Wheel seals all round, brake pads n rotors all round, previous owner claimed to have had "front end rebuilt."
That's one place to start, first check the brake pads/calipers/rotors to see if anything is loose, dragging, binding.

Does the sound change when applying the brakes slowly/lightly in Forward or Reverse?

What specifically was replaced for "wheel seals all around"??

Then consider the front hubs, wheel bearings, and CV joints (Birfields or "Birfs").

Quick check to see if the steering knuckles are low on grease. There is a square pipe plug on the top front of each steering knuckle,
you can remove that (clean off around the plug first) then stick a screwdriver into the hole as far as it will go and pull it straight out
like a dipstick. There should be about an inch (or more) of grease showing. You can also look into the hole using a bright flashlight.
You can also look at the swivel balls, is there a horizontal line of grease present? If unsure take a clean finger and wipe downward starting at the top
of the swivel ball (where you see wear from the wipers), if there's grease in the knuckles you should feel it getting slippery as you swipe downward.

Might help to post up a photo of your steering knuckles/swivel balls

If you aren't familiar with the front axle on your FZJ80 this video might be useful:

 

[jonheld]

CALIPER BOLTS
Any work on the front end would have required the removal of calipers.
Should be torqued to 90 ft/lbs.

 

[ghostofamerica]

Wheel seals all round, brake pads n rotors all round, previous owner claimed to have had "front end rebuilt."
That's one place to start, first check the brake pads/calipers/rotors to see if anything is loose, dragging, binding.

Does the sound change when applying the brakes slowly/lightly in Forward or Reverse?

What specifically was replaced for "wheel seals all around"??

Then consider the front hubs, wheel bearings, and CV joints (Birfields or "Birfs").

Quick check to see if the steering knuckles are low on grease. There is a square pipe plug on the top front of each steering knuckle,
you can remove that (clean off around the plug first) then stick a screwdriver into the hole as far as it will go and pull it straight out
like a dipstick. There should be about an inch (or more) of grease showing. You can also look into the hole using a bright flashlight.
You can also look at the swivel balls, is there a horizontal line of grease present? If unsure take a clean finger and wipe downward starting at the top
of the swivel ball (where you see wear from the wipers), if there's grease in the knuckles you should feel it getting slippery as you swipe downward.

Might help to post up a photo of your steering knuckles/swivel balls

If you aren't familiar with the front axle on your FZJ80 this video might be useful:

Wheel seals all round, brake pads n rotors all round, previous owner claimed to have had "front end rebuilt."
That's one place to start, first check the brake pads/calipers/rotors to see if anything is loose, dragging, binding.

Does the sound change when applying the brakes slowly/lightly in Forward or Reverse?

What specifically was replaced for "wheel seals all around"??

Then consider the front hubs, wheel bearings, and CV joints (Birfields or "Birfs").

Quick check to see if the steering knuckles are low on grease. There is a square pipe plug on the top front of each steering knuckle,
you can remove that (clean off around the plug first) then stick a screwdriver into the hole as far as it will go and pull it straight out
like a dipstick. There should be about an inch (or more) of grease showing. You can also look into the hole using a bright flashlight.
You can also look at the swivel balls, is there a horizontal line of grease present? If unsure take a clean finger and wipe downward starting at the top
of the swivel ball (where you see wear from the wipers), if there's grease in the knuckles you should feel it getting slippery as you swipe downward.

Might help to post up a photo of your steering knuckles/swivel balls

If you aren't familiar with the front axle on your FZJ80 this video might be useful:

Kernal, there's not enough grease in the balls. do you have a recommendation for type of readily available grease i can pick up at walmart or autozone? thank you

 

[Comet]

Birfs should be 3/4 full. @Kernal will advise on grease with moly in it. I go cheap and check at every oil change.

 

[BTLSHP]

Any decent lithium base grease fortified with molybdenum. There is a strong inclination toward Valvoline Platinum Syn here, but if you think you are coming back later to do the rebuild use what you can.

 

[clx16]

@ghostofamerica what is the verdict on the calipers? What you are explaining sounds a lot like what @jonheld is mentioning. You may find some shinny spots on the inside of your wheels.

another thing that comes to mind would be if your exhaust mounts are letting your muffler touch the rear drive shaft as you mentioned some orientation making a difference. also a look for shiny spots.

 

[ghostofamerica]

@ghostofamerica what is the verdict on the calipers? What you are explaining sounds a lot like what @jonheld is mentioning. You may find some shinny spots on the inside of your wheels.

another thing that comes to mind would be if your exhaust mounts are letting your muffler touch the rear drive shaft as you mentioned some orientation making a difference. also a look for shiny spots.

Hey @clx16 it was definitely the lack of grease in the ball housings. I filled them today. Grinding my teeth over how much damage was done. They should have been full two months ago when seals were replaced. I will check them way way more often going forward. Did check the calipers, nice and tight.

 

[ghostofamerica]

Any decent lithium base grease fortified with molybdenum. There is a strong inclination toward Valvoline Platinum Syn here, but if you think you are coming back later to do the rebuild use what you can.

Hey @BTLSHP , I think I just bought myself a rebuild sooner rather than later. The grease fixed the noise, mostly. I definitely shortened the life span of the birfs tho. Can hear it popping in low coasting downhill. It stopped tapping on the blacktop. I got some supertech for now. Just happened to be the closest place.

 

[ghostofamerica]

Birfs should be 3/4 full. @Kernal will advise on grease with moly in it. I go cheap and check at every oil change.

Hey @Comet , got some supertech moly-lith. It stopped the noise, which is good and bad news. Time will tell, eh?

 

[ghostofamerica]

CALIPER BOLTS
Any work on the front end would have required the removal of calipers.
Should be torqued to 90 ft/lbs.

Thanks @jonheld, I checked em. Turned out I used just about all the grease in my birfs over the span of two months. Never again!

 

[ghostofamerica]

does it sound like the front or back where the noise is coming from?

remove the front drive shaft and lock the centre diff and test as RWD only, this will tell you whether its front or back

id be looking at uni's (F & R) or even the drive shaft slip yoke could be binding up if theres an associated vibration

Hey @robnicko it was the front, for sure. I filled the birfs today and will be checking more regularly. I was born in '77, but this is my first 4WD with a solid front axle. V. different from CV joints. I remember working for a mechanic back in '97 when my rig would have been brand new. People came in for "Lube, oil, and filter, all the time. I asked ol' Mundy what the heck the lube part was. He said most cars didn't have lubricatable parts by then and that it was from back when mechanics would have to lube all these ports to keep the parts moving. s***, I guess I've got homework. Have to find out where all the lube points are on my 80 if I want to keep it for long.

 

[ghostofamerica]

Have you checked your fluid level on the birfs?

@Fj80oregon Yep, nailed it. Thank you

 

[ghostofamerica]

Wheel seals all round, brake pads n rotors all round, previous owner claimed to have had "front end rebuilt."
That's one place to start, first check the brake pads/calipers/rotors to see if anything is loose, dragging, binding.

Does the sound change when applying the brakes slowly/lightly in Forward or Reverse?

What specifically was replaced for "wheel seals all around"??

Then consider the front hubs, wheel bearings, and CV joints (Birfields or "Birfs").

Quick check to see if the steering knuckles are low on grease. There is a square pipe plug on the top front of each steering knuckle,
you can remove that (clean off around the plug first) then stick a screwdriver into the hole as far as it will go and pull it straight out
like a dipstick. There should be about an inch (or more) of grease showing. You can also look into the hole using a bright flashlight.
You can also look at the swivel balls, is there a horizontal line of grease present? If unsure take a clean finger and wipe downward starting at the top
of the swivel ball (where you see wear from the wipers), if there's grease in the knuckles you should feel it getting slippery as you swipe downward.

Might help to post up a photo of your steering knuckles/swivel balls

If you aren't familiar with the front axle on your FZJ80 this video might be useful:

@Kernal Thanks again, this is all great stuff. The seals I had done were inner/outer bearing seals front and rear, and the ball seals. This video is going to be vital when I have to rebuild it all because I rode them dry for two weeks. There was about half an inch of grease on the screwdriver. Used it all up in two months. Need to do an oil change this weeknd and I plan on synchronizing the two jobs for future changes. Also going to look into other greasing points on the vehicle so I don't break anything else.
The noise did stop, for the most part. It still pops coasting downhill in low.

 

[robnicko]

Hey @robnicko it was the front, for sure. I filled the birfs today and will be checking more regularly. I was born in '77, but this is my first 4WD with a solid front axle. V. different from CV joints. I remember working for a mechanic back in '97 when my rig would have been brand new. People came in for "Lube, oil, and filter, all the time. I asked ol' Mundy what the heck the lube part was. He said most cars didn't have lubricatable parts by then and that it was from back when mechanics would have to lube all these ports to keep the parts moving. s***, I guess I've got homework. Have to find out where all the lube points are on my 80 if I want to keep it for long.

Its all a learning experience with these trucks

I have a few years on you, 70 but 77 was my 1st album - KISS Alive II

 

[ppc]

There was about half an inch of grease on the screwdriver. Used it all up in two months.

Doubt it was "used" sounds more like not properly filled when the joints were serviced.
In the future if you continuously have to add grease then you have a failed inner axle seal, plugged up breather and diff full of gear oil/grease mixture. It's either that or grease is being slung out of the felt seals.

 

[Kernal]

^^^This^^^

@ghostofamerica : what did you do to stop the noise, or did it stop on it's own??

If you don't have one yet, buy a good quality long arm manual pump grease gun with a flexible hose, the type that will hold standard 14oz tubes.

The nozzle of most grease guns (usually) fit into the inspection port (after removal of the pipe plug) of the steering knuckles, if it doesn't get a narrower nozzle.

One method, if the grease is very low, is to pump a tube into each side, or pump half a tube into each side, go for a drive and recheck the grease level.
It will get slung around inside but you can get a rough idea. You want enough grease to coat the inside of the knuckle (to keep water out) but
also high enough to keep the spindle bushing lubricated.

Valvoline Palladium is 3% Moly (Molybdenum)
Valvoline Full Synthetic is something less than 3%
Any lithium base grease with Moly is good.

 

[ghostofamerica]

^^^This^^^

@ghostofamerica : what did you do to stop the noise, or did it stop on it's own??

If you don't have one yet, buy a good quality long arm manual pump grease gun with a flexible hose, the type that will hold standard 14oz tubes.

The nozzle of most grease guns (usually) fit into the inspection port (after removal of the pipe plug) of the steering knuckles, if it doesn't get a narrower nozzle.

One method, if the grease is very low, is to pump a tube into each side, or pump half a tube into each side, go for a drive and recheck the grease level.
It will get slung around inside but you can get a rough idea. You want enough grease to coat the inside of the knuckle (to keep water out) but
also high enough to keep the spindle bushing lubricated.

Valvoline Palladium is 3% Moly (Molybdenum)
Valvoline Full Synthetic is something less than 3%
Any lithium base grease with Moly is good.

Got it. Yes, I put half a tube in each side yesterday and drove home. Bought two tubes so will recheck today and add if necessary. I got the grease gun from walmart, so it's a PITA but it works for the steering knuckles. Thanks again @Kernal