Front & Rear Differential Metal Shavings = Rebuild and/or Replace? (3 Viewers)

[ghong14]

Mudders, looking to get some advice on a new development for my 98'LX470's FRONT & REAR Differential. Truck has 191K miles.

Technician from a reputable shop I have going to for years found metal shaving in the front and rear differential when they did the fluid replacement. Spoke to owner and recommended a differential rebuild or an OEM swap. Have not experienced any symptoms during my drive.

A few questions I have:
-How imminent is this issue (especially for the back differential since the metal shavings are larger)?
-Preference between rebuild using parts from Cruiser teq and full OEM swap?

Photo below are from the REAR Differential.

 

[Trunk Monkey]

Some amount of shavings are normal. There's one piece in there that's a little concerning. If you're not feeling any driveline vibrations I wouldn't rebuild just yet.

 

[OEMGUY0720]

Is that the biggest material you got from draining the diff fluid? The differential/third member is a rotating component, you would instantly feel if the vibration is already excessive and warrants to be serviced/replaced.

 

[ghong14]

Is that the biggest material you got from draining the diff fluid? The differential/third member is a rotating component, you would instantly feel if the vibration is already excessive and warrants to be serviced/replaced.

Not feeling vibration while driving front either front or rear. Yes that is the biggest piece and it came from the back.

 

[OEMGUY0720]

Not feeling vibration while driving front either front or rear. Yes that is the biggest piece and it came from the back.

I think you're good. I would do a drain and fill again after this one you just did in about 5,000 miles just for safety.

 

[TahoeZ]

I agree with others above. Definitely keep an eye on it. You might consider running a heavier gear oil and definitely change the oil more frequently to keep tabs on deteriorating condition of gears.

The front diffs on these are fairly weak and known to fail but the rears are quite stout. It's fairly straightforward to pull a third-member out of a parts/junkyard vehicle and swap the entire thing in.

 

[SteveH]

It's fairly straightforward to pull a third-member out of a parts/junkyard vehicle and swap the entire thing in.

If you need a replacement diff, I would do this. OEM diffs (rears) are indeed bombproof. I actually found an entire locker rear axle from a '99 Land Cruiser for $400 at a local yard, and swapped in the entire axle and used aftermarket wiring for the locker. My old axle had 310K on it, and the new one only had 200K, which was nice, too.

 

[ghong14]

It's fairly straightforward to pull a third-member out of a parts/junkyard vehicle and swap the entire thing in.

If you need a replacement diff, I would do this. OEM diffs (rears) are indeed bombproof. I actually found an entire locker rear axle from a '99 Land Cruiser for $400 at a local yard, and swapped in the entire axle and used aftermarket wiring for the locker. My old axle had 310K on it, and the new one only had 200K, which was nice, too.

I believe my cruiser has a central differential lock. Did your have a rear lock?

I agree with others above. Definitely keep an eye on it. You might consider running a heavier gear oil and definitely change the oil more frequently to keep tabs on deteriorating condition of gears.

The front diffs on these are fairly weak and known to fail but the rears are quite stout. It's fairly straightforward to pull a third-member out of a parts/junkyard vehicle and swap the entire thing in.

How often would you recommend the oil change on front and rear differential. Also I am currently running 75W-90. What would you recommend?

 

[TahoeZ]

If it were mine I would change it every 5k to keep an eye on additional deterioration.

75/140 oil

 

[ghong14]

Other than seeing the metal shaving how else would I assess the state of the differential other than a catastrophic failure? Are there driving characteristics or specific noise?

 

[Trunk Monkey]

The front diffs on these are fairly weak and known to fail but the rears are quite stout. It's fairly straightforward to pull a third-member out of a parts/junkyard vehicle and swap the entire thing in.

The 98/99 MY have a 2 pinion diff, 00+ is 4 pinion. Of those that do break, it's more common for the earlier 2 pinion. They are not known to fail. They can break under certain circumstances, usually wheeling and a shock load with traction, but it's still pretty rare.

75w90 is fine, unless your LX has the LSD rear.

 

[ghong14]

The 98/99 MY have a 2 pinion diff, 00+ is 4 pinion. Of those that do break, it's more common for the earlier 2 pinion. They are not known to fail. They can break under certain circumstances, usually wheeling and a shock load with traction, but it's still pretty rare.

75w90 is fine, unless your LX has the LSD rear.

How would I know whether my lx has a LSD rear?

 

[Bisho]

How would I know whether my lx has a LSD rear?

All LXs have the LSD rear, and they still take 75W90. Just make sure the brand you buy has LSD friction modifier in it. Most do these days.

 

[x8o8drifter]

All LXs have the LSD rear, and they still take 75W90. Just make sure the brand you buy has LSD friction modifier in it. Most do these days.

No they don't.
98 & 99 LC optional rear locker or open. No LSD.
98 & 99 LX has LSD.
LC & LX 2000 and on have just ATRAC. With the option for AHC on the last to years of LC.

In OPs case he has a LSD.

 

[ghong14]

I got the Valvine 75w90. I believe the blend has LSD blend in it.

 

[x8o8drifter]

I got the Valvoline 75w90. I believe the blend has LSD blend in it.

Which one?
Conventional/Synthetic?

The single conventional one the offer say its to be used just to top off a LDS. Not replace it.

The 3 synthetic ones seem to have a friction modifier based on the label.
Hope you bought synthetic.

 

[baltistyle]

FWIW, when I recently did fluid in my rear diff, I only had what looked like dust on my magnetic plug. That was after a very long period of likely having never been changed. I think someone that has actually rebuilt a diff before should weigh in on exactly what part that larger piece of metal is. You can see if it were to be unfolded it’s a very thin piece of steel and to me looks like a piece of a bearing shell… you can always ride it until it dies, but of course that risk is up to you..I might also recommend a short interval for another flush since big material doesn’t always flow to the hole upon draining.

 

[ghong14]

Which one?
Conventional/Synthetic?

The single conventional one the offer say its to be used just to top off a LDS. Not replace it.

The 3 synthetic ones seem to have a friction modifier based on the label.
Hope you bought synthetic.

Synthetic

FWIW, when I recently did fluid in my rear diff, I only had what looked like dust on my magnetic plug. That was after a very long period of likely having never been changed. I think someone that has actually rebuilt a diff before should weigh in on exactly what part that larger piece of metal is. You can see if it were to be unfolded it’s a very thin piece of steel and to me looks like a piece of a bearing shell… you can always ride it until it dies, but of course that risk is up to you..I might also recommend a short interval for another flush since big material doesn’t always flow to the hole upon draining.

Yes I am planning another drain in 5K