Going through baseline projects on my 92 LC. I noticed a layer of grease around the birfs/knuckles. Would appreciate hearing from those who’ve had this issue. Are the wipers or inner seal shot? Should the knuckles be rebuilt?
Knuckle leak question (2 Viewers)
- Thread starter ocinataS
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Pretty messy. If you don't know the history, put it all right to the best of your ability.
Here, the mess is mostly on the lower half of everything. This could be a sign that it's flung most of the grease out already and has been running low. Best to pull the square-headed plug that gives you a peek in and see what the lube level looks like. It might be scary low.
Here, the mess is mostly on the lower half of everything. This could be a sign that it's flung most of the grease out already and has been running low. Best to pull the square-headed plug that gives you a peek in and see what the lube level looks like. It might be scary low.
looks like you’re probably due for a front axle rebuild...inner axle seals are most likely letting diff oil pass to the knuckle which mixes with the grease in the knuckle and creates “birf soup”. You’ll want to make sure your knuckles have sufficient amount of grease in them and plan on a rebuild in the future. Check the FAQ for front axle rebuild.
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- #4
It’s very low. Will fill up tomorrow for the time being.
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- #5
Sounds like the way to go. Will fill up tomorrow. Not sure what the front diff looks like. Fill plug is seized, so will work on getting it out to see what oil looks like in there.
You want to fill the trunnion box (what the square head plug taps into) with the appropriate moly fortified grease. It will keep leaking out until ithe axle is rebuilt with new parts. It's probably birf soup in there, what's left of it anyway, but you need to keep it topped up until it gets fixed. Most likely, the failiure of the inner axle seal allows the moly to contaminate the lube in the pumpkin and axle. Best to use some cheap lube and run it a little then change it, in order to get most of the moly from inside where it contaminates things and may cause issues with premature wear in some bearings.
That stuck plug can be a PITA. If not too chewed up already try to tighten it a little, as that can help break them lose. Also, if you can keep an impact socket on the plug, use it to bang away on the plug. Juicing it with PBBlaster may help, too. You need to get in there, as you'll likely find the diff low on gear lube due tio its mixing with things out toward the hubs.
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The spider webs make me think it’s been sitting unused for awhile. If that’s the case, the moly fortified grease can separate a little and that’s what is probably leaking past the felt wiper seals. Waking the beast from sleep mode is an exciting experience and there will be gremlins in need of addressing. Me, I would fill the birf 3/4 full and monitor the leak as I addressed other symptoms of coming out of hybernation.
I used the valvoline moly grease during my rebuild but I found that O’Reillys had their own brand so I picked up some of that stuff as back up or for future top ups. Not that the stuff is expensive but I’m sure it’s a few bucks cheaper. Good call on it sitting for a while, first thing I noticed was those webs!
Zjohnsonua
SILVER Star
Several valid points were listed above. My vote is knuckle build. Reasoning below:
1 - There's more going on in there than just grease and oil storage, and you are baselining the rig. Future You is going to want to know what shape those birfs, wheel bearings and brake parts are in. See Kurt or Marlin for the req'd parts.
2 - This is a good project to learn your rig on, with minimal opportunity for foul ups. There's lot of documentation here to lean on if needed.
3 - Knuckle rebuild is a rite of passage for new TLC owners. It should be done by the owner and the mess should be appreciated! Clear your schedule for the day and enjoy the task.
Enjoy the 80. It's not great at anything, but it's exceptionally good at a LOT.
1 - There's more going on in there than just grease and oil storage, and you are baselining the rig. Future You is going to want to know what shape those birfs, wheel bearings and brake parts are in. See Kurt or Marlin for the req'd parts.
2 - This is a good project to learn your rig on, with minimal opportunity for foul ups. There's lot of documentation here to lean on if needed.
3 - Knuckle rebuild is a rite of passage for new TLC owners. It should be done by the owner and the mess should be appreciated! Clear your schedule for the day and enjoy the task.
Enjoy the 80. It's not great at anything, but it's exceptionally good at a LOT.
Everyone says the same thing "not hard to do but messy". There's a walkthrough video in OTRAMM's Youtube channel. It seems pretty straight forward, the only thing I have some confusion with is how to flip the birfs from one side to the other before repacking them.
Zjohnsonua
SILVER Star
Gotta pop the birfs off the axle shaft then swap which shaft they're installed on. Stretches the life of the birf by putting load on the other side of the ball pockets. Have new inner circlips on hand when doing that swap.
@Zjohnsonua Thanx for the info. I bought the clips already but i'm a 1.5 
mechanic and haven't found enough info on it to feel comfortable enough to tackle it yet. Haha
mechanic and haven't found enough info on it to feel comfortable enough to tackle it yet. Haha
Zjohnsonua
SILVER Star
No worries. Search around in here for a how-to thread. The process may look a little violent, but it's straightforward. It's also not a required step, but it does extend the life of the birf.
- Thread starter
- #14
Thanks for the plug tips. I went at it last night but it won’t budge. Didn’t want to chew it up too bad without trying Free All, so I’m going to see if I can find some at the parts store.
The spider webs lol. From the CARFAX, it was driven sparingly by the old couple I bought it from. I haven’t any more live ones, but I hunted down a gnarly looking black Widow in the rear a few days ago that rebuilt her huge web every night after I would tear it down. I’ll pick up insecticide while I’m out.
Depending on what i decide to do with the truck, I’ll either do the knuckle service myself or have a local shop do it. I live near Valley Hybrids and got a quote for a regear that includes a knuckle rebuild. Pricey, so it may be a little while if I go that route. Lots of other things to take care of first. I have the valve cover, throttle body, and air intake chamber out now.
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- #15
Thanks, yes I’d prefer to do it myself. But may take care of it if I regear.
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- #16
Thanks, yes, the cheaper house brand will do for fill ups till I take care of it.
I would vote for doing it yourself as well. Since doing my front axle rebuild, I’ve been into the hubs numerous times whether it was doing brakes or checking my bearings...it just gets easier every time! I actually had to go inside my passenger hub today since I think I may have tightened my bearing lock nuts too tight when doing a brake overhaul about a month ago. Took about an hour and half from jacking the tire up to tightening all the lug nuts at finish. This time I torqued inner nut to 20 ft lbs and outer nut to 47 ft lbs...not that you need to know this now but for future reference. 
JEEZUS you got pics of that black widow?
Dirty Koala
SILVER Star
If you decide to not do it yourself, you are in very good hands with Georg....don't take it anywhere else if you are in driving distance for Valley Hybrids.
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- #20
