"poop" in front differential (1 Viewer)

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lovetoski

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Per advice from this board, I 've been replacing all the fluids in my recently purchased fzj80 (94, with 200,000 miles). From the info I have, it apprears to have been extremely well maintained. All fluids looked/smelled good. Looks new.

However, the front differntial really threw me for a loop. For those of you with kids, lets just say thick and greeen...

The rear diff looked golden, like a rich amber beer. The front was disgusting...some thick green glop barely dripped from the drain hole.

Is this bearing grease working back to the diff...or did somebody put the wrong thing into the third, or ????

All opinions welcome...

By the way, note to all...if you are replacing the oil in the diff and the air temp is low, it would be good to warm the oil before trying to pump it under the truck. 3.5 qts at 28 degrees on your back is hard work.
 
Doug,
The poop in your front diff is grease that has been pumped in the front knuckles by using the square plugs on the back of the knuckles. It is very likely that your axle tube seals are shot and possibly worse.

Christo posted some pics of a front diff that looked just like you describe. IIRC, the customer was facing some expensive repairs to the 3rd member and birfields. Hopefully yours isn't that bad.

-B-
 
Thanks Beowolf,

Your answer is pretty much what I was expecting. It seemed like grease, and that meant it had to come from the hubs.

It may be that it was sold for this reason - if so, anything that I should look for that might be especially worn?

Are the axle hub seals hard to replace? I was just about to do a full front axle rebuild on my fj60 when we bought the fzj80. While I haven't done it yet, it appears it's messy but straitforward.

Thanks!
 
Doug,
I will defer to others on what you need to do now that you've discovered it was run with grease instead of gear oil for an undetermined time. Christo has seen this before and can tell you what they had to do to get the truck back to normal. Doug and others may have some suggestions.

I think you need to plan on a weekend *real soon* to tear into the front end and find out what is going on.

-B-
 
Birfield repack, axle seals and trunion bearings. Refill the front diff with gear oil, and change the gear oil about once a week until it lightens up....may take a few changes. Hopefully the birfs and gears, etc. aren't too messed up...

-H-
 
I have nothing to add to the bad news, but since the subject was "poop" in the diff I though I would add that when the diff fluid is drained (front and rear) there is about a 1/2 inch dip below the plug that retains "poop". I know some tilt/jack the axles to get more of the diff oil to drain but this does not get the heavy poop out.
Bill
 
If your diff is not whining and your birfs are not clicking, then I don't understand the doom and gloom. Obviously, you need new seals in your front axle, so I'd do that PLUS the front axle vent extension and removal of the 1-way flapper valve. The vent mod helps prevent incursion of grease into the diff from the vacuum of the valve's operation.

If you're truly paranoid about the 3rd, do a couple diff changes as suggested weekly above and see if there's any noise. At least if you discover the 3rd needs replacement (I'd be surprised), then it can all be done at once since
75% of the work is the birfields and seals.

Doug
 
There is no noise from the diff, nor from the birfs, so (fingers crossed) maybe I'll luck out. Ordering parts today.

What's with the flapper valve though...is it in the axle where the vent tube inserts?

Also, is there a special tool needed to remove/replace the axle seal? I think I have everything I need for the wheel and knuckle bearings.

Really appreciate the help/advice.
 
hey ya'll. i just completed this entire job on my 94 with a friend. repacked, resealed, new bearings and drained the "poop" from the front diff. i'm now on the 4th diff oil change in 4 weeks and all is going well. breather tube extended and the fluid is draining more clearly and way less thick. no clicking or other dredded sounds heard from the diff. and to top all that, the front still locks in twice as fast as the rear diff. good luck , its a total pain in the ass!!!!
 
I had 200,000 mi and the poop. The birfields were worn so I got Newfields and that solved the problem.
 
Doug,

>> What's with the flapper valve though...is it in the axle where the vent tube inserts? <<

It's on the other end of the vent tube (aka diff breather tube.) You can mod the one on the rear axle. See the diff breather extension write up in the archives of this section.

>> Also, is there a special tool needed to remove/replace the axle seal? <<

Standard T-handle seal removal tool.

-B-
 
Thanks B,

Parts coming from C-Dan. Christo gave me some good advice too - if it was his truck he'd pull the third to really clean the grease/oil "poop" combo out - so I'll do that. I'll check the writeup re vent mods - thanks. It's all coming together. A long cold day in the driveway, but at least we don't have rain in the forecast!

Appreciate the fast, thorough, response from all. Wish me luck. I'll let you know how it goes.
 
Since you just bought it the dealer or previous owner might have pumped the knuckles "full" of grease. This will force the grease past the seals at higher speeds causing your condition. I would try a refill and a couple of drains and make sure at lube time you only put 5-6 squirts in the knuckles. I doubt you have a problem with the seals unless your knuckles are dripping on the floor.
 
Pit,

Pumping too much grease through the square plug as you're alluding to would generally cause it to come out the exterior sweep seals on the inner hub face as these are meant to weep grease constantly. The grease will of course take the easiest way out if there's excess. So if it goes into his diff instead, the opposite conclusion of your post would be reached - that the axle seals are so worn the grease get by them more easily than the sweep seals. At his miles, I'd say it's time for axle seals if he cannot find records when it was done.

Good advice on the 5-6 pumps into the square plug.

Doug
 
Doug your right, but there could be a chance that the seals are not worn to the point they need to be replace if someone filled up the steering knuckles and drove at high speeds this would cause enough pressure to force it into the differential as well as on the outside of the knuckle. Just thought he might try the cleaning out and refill and then check and see how it was doing. As long as everything is well lubed he is not going to hurt anything. Norm from OZ suggested this to me several years ago and some 50K miles and mine have been fine. By the way, dealers don't lube steering knuckles and if you ask them too they fill them to the top. I found this out the hard way. If I was buying a used LC and the guy say he had it regularly serviced at the Toyota dealship I would be worried.
 
Hmmmmmm,


Dealer bashing?

:'(
 
Bashing ??? I have found that most dealers don't see enough FZJ80's to have a handle on them. This has been my reality. I have found that with the little operators you can talk to them and they are available to talk too. At the dealership I would alway end up with a service writer that was good at Camry's but not very knowledgable with LC's. JMHO
 
2 tools you can use to pull the inner seal.

I pulled one with a "cats claw" (carpenters tool) and one with a sliding hammer.

The cats claw worked great, just make sure you hook it right and it comes pretty easily. No scratching or marring.
 
Pitbull/Doug,

I really appreciate the additional thoughts on my front differential problem. I don't have access to service records, though I'm pretty sure that most/all service was done at one or two different Dealerships. The fzj80 is my wife's daily driver, and our weekend ski vehicle. Yearly milage will be ~20,000. It well may be that there was simply too much grease pumped into the square hole. But, my personality is kinda of like a landcruiser anyway...I'm going to do the full front axle service, that way I'll know for sure that it's fixed. I travel some for work, and things usually break while I'm gone. This way I'll know that this is one thing that won't break for a long time.

Now I need to go read the article about doing a front axle service again! Gotta have the whole plan clear in mind before I start.

Thanks again for the help and suggestions.
 

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