Found something during diff fluid change (1 Viewer)

[yukon]

This was supposed to be a boring post to my build thread that no one will read, but then something interesting happened. I found something wrong during routine maintenance.

99 LX with 145k front diff no weirdness inspired the fluid change. Fluid looked as new, not even honey colored.

Opinions

 

[AlpineAccess]

Which diff?

Obviously not great but not a big deal either - looks like the outside edge of a ring gear tooth (approximately 1/100th) of the surface on one of dozens of teeth.

If you're concerned there may be more (unlikely) you can pull the cover off if its the rear diff and spin the axle looking for which tooth it is.

Your 99 is open fronts and rears so no need to have LSD additive or anything.

 

[yukon]

Front diff.

Good points, edited the post to say front diff.

Let's see what everyone else says, but currently inclined to just run it. But really don't want it to grenade somewhere I can't get out of.

 

[yukon]

Also, the 99 has an open rear not an LSD? I thought I read somewhere it had a factory LSD.

 

[AlpineAccess]

Also, the 99 has an open rear not an LSD? I thought I read somewhere it had a factory LSD.

Open rear with locker

 

[AlpineAccess]

Front diff.

Good points, edited the post to say front diff.

Let's see what everyone else says, but currently inclined to just run it. But really don't want it to grenade somewhere I can't get out of.

You'll have some opinions on the front diff. Rear I'd run without any concerns with a small chip like that.

Front diff on the early 100's (like ours) is a 2 pinion and not as durable as the 4 pinion.

 

[yukon]

You'll have some opinions on the front diff. Rear I'd run without any concerns with a small chip like that.

Front diff on the early 100's (like ours) is a 2 pinion and not as durable as the 4 pinion.

Yup, totally agree. Rear I wouldn't have thought twice about it, not sure how the fronts fail (will do more research) but I am now worried that it could be a liability once I get the rig fully loaded for my planned RTW trip.
I had planned on an ARB front and rear, but scratched those plans after thinking really hard about budget and intended uses; I just don't need one.

 

[SS100]

I've run my front diff with a slight humming noise after getting some very similar debris on the magnetic drain plug for over 50k miles without an issue.

 

[Otis]

Also, the 99 has an open rear not an LSD? I thought I read somewhere it had a factory LSD.

My '99 had a factory LSD in the rear and I would guess yours does... See this thread: LX470 Rear diff LSD fluid

 

[AlpineAccess]

I've run my front diff with a slight humming noise after getting some very similar debris on the magnetic drain plug for over 50k miles without an issue.

This is probably more a function of the fluid, at least in my case it was. I swapped in dyno gear lube in the front and had humming present. Swapped to a full synthetic, quiet as a church mouse.

If you've had some wear a lash adjustment may improve the whine.

 

[AlpineAccess]

My '99 had a factory LSD in the rear and I would guess yours does... See this thread: LX470 Rear diff LSD fluid

No locker, LSD. Locker, open rear. Mutually exclusive.

 

[AlpineAccess]

Yup, totally agree. Rear I wouldn't have thought twice about it, not sure how the fronts fail (will do more research) but I am now worried that it could be a liability once I get the rig fully loaded for my planned RTW trip.
I had planned on an ARB front and rear, but scratched those plans after thinking really hard about budget and intended uses; I just don't need one.

Front's in general are failing from low traction spinning combined with a sudden shock load. Happens when climbing and spinning and hooking up with a surface (or snow, etc.). If I'm ever in an area with low traction and feel wheel spin I two foot that area to prevent damage. AKA "off road cruise control", smooths out the bumps anyways and prevents banging off of skid plates.

I'd like an ARB front as well but cost is prohibitive. I'll likely end up sourcing a '00-02 front member if I blow mine.

 

[Otis]

No locker, LSD. Locker, open rear. Mutually exclusive.

Point was that he may consider using LSD fluid in the rear... I don't know if it really matters though...

 

[JunkCrzr89]

Also, the 99 has an open rear not an LSD? I thought I read somewhere it had a factory LSD.

Open rear with locker

98-99 LX had LSD rear. 98-99 LC had open rear w/ locker option.

 

[JunkCrzr89]

Point was that he may consider using LSD fluid in the rear... I don't know if it really matters though...

Probably should...or at least throw in an LSD additive.

 

[ramangain]

This is MUD, right?

You'll need to rebaseline EVERYTHING, rebuild your entire front end, and finish it off by overgreasing your slip yokes. Only then you can try off-roading on some light gravel and leaves to ensure everything is OK.

 

[AlpineAccess]

This is MUD, right?

You'll need to rebaseline EVERYTHING, rebuild your entire front end, and finish it off by overgreasing your slip yokes. Only then you can try off-roading on some light gravel and leaves to ensure everything is OK.

Leaves are slippery, I'd recommend having a locker to make sure the diff doesn't explode.

 

[AlpineAccess]

98-99 LX had LSD rear. 98-99 LC had open rear w/ locker option.

Correct correct - OP I didn't look at you having an LX. Important piece of the pie.

 

[yukon]

So we have confirmed I DO have an LSD.

Now, will the front explode? I'm guessing not

 

[JunkCrzr89]

So we have confirmed I DO have an LSD.

Now, will the front explode? I'm guessing not

Maybe eventually because 2-pinion, but probably not because of those chips you found.